WO2008113707A1 - Puce de capteur de pression - Google Patents
Puce de capteur de pression Download PDFInfo
- Publication number
- WO2008113707A1 WO2008113707A1 PCT/EP2008/052825 EP2008052825W WO2008113707A1 WO 2008113707 A1 WO2008113707 A1 WO 2008113707A1 EP 2008052825 W EP2008052825 W EP 2008052825W WO 2008113707 A1 WO2008113707 A1 WO 2008113707A1
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- WIPO (PCT)
- Prior art keywords
- layer
- pressure sensor
- sensor chip
- silicon
- differential pressure
- Prior art date
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- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 105
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 104
- 239000010703 silicon Substances 0.000 claims abstract description 104
- 239000012528 membrane Substances 0.000 claims abstract description 41
- 230000001419 dependent effect Effects 0.000 claims abstract description 23
- 239000002131 composite material Substances 0.000 claims abstract description 15
- 238000004519 manufacturing process Methods 0.000 claims description 19
- 238000000034 method Methods 0.000 claims description 16
- 238000002513 implantation Methods 0.000 claims description 14
- 239000000463 material Substances 0.000 claims description 14
- 238000005259 measurement Methods 0.000 claims description 13
- 230000008021 deposition Effects 0.000 claims description 9
- 150000002500 ions Chemical class 0.000 claims description 8
- 125000006850 spacer group Chemical group 0.000 claims description 7
- 239000011810 insulating material Substances 0.000 claims description 4
- 238000002161 passivation Methods 0.000 claims description 4
- 238000005137 deposition process Methods 0.000 claims description 3
- 238000005496 tempering Methods 0.000 claims 1
- 239000000758 substrate Substances 0.000 abstract description 13
- 238000009530 blood pressure measurement Methods 0.000 abstract description 3
- 235000012431 wafers Nutrition 0.000 description 16
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 14
- 238000011161 development Methods 0.000 description 12
- 238000000151 deposition Methods 0.000 description 8
- 238000005530 etching Methods 0.000 description 8
- 235000012239 silicon dioxide Nutrition 0.000 description 7
- 239000000377 silicon dioxide Substances 0.000 description 7
- 229910004298 SiO 2 Inorganic materials 0.000 description 6
- 239000012212 insulator Substances 0.000 description 6
- 238000001020 plasma etching Methods 0.000 description 6
- 229910052581 Si3N4 Inorganic materials 0.000 description 5
- 238000009413 insulation Methods 0.000 description 5
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 5
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 4
- 238000000137 annealing Methods 0.000 description 4
- 229910052796 boron Inorganic materials 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 238000010292 electrical insulation Methods 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- 238000001465 metallisation Methods 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 3
- 239000007858 starting material Substances 0.000 description 3
- 238000011835 investigation Methods 0.000 description 2
- 229910021421 monocrystalline silicon Inorganic materials 0.000 description 2
- -1 nitrogen ions Chemical class 0.000 description 2
- 238000000623 plasma-assisted chemical vapour deposition Methods 0.000 description 2
- 229920001296 polysiloxane Polymers 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000001312 dry etching Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005670 electromagnetic radiation Effects 0.000 description 1
- 230000002706 hydrostatic effect Effects 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- QPJSUIGXIBEQAC-UHFFFAOYSA-N n-(2,4-dichloro-5-propan-2-yloxyphenyl)acetamide Chemical compound CC(C)OC1=CC(NC(C)=O)=C(Cl)C=C1Cl QPJSUIGXIBEQAC-UHFFFAOYSA-N 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N nitrogen Substances N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 238000000206 photolithography Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000000992 sputter etching Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
- 238000003631 wet chemical etching Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
- G01L9/0041—Transmitting or indicating the displacement of flexible diaphragms
- G01L9/0051—Transmitting or indicating the displacement of flexible diaphragms using variations in ohmic resistance
- G01L9/0052—Transmitting or indicating the displacement of flexible diaphragms using variations in ohmic resistance of piezoresistive elements
- G01L9/0054—Transmitting or indicating the displacement of flexible diaphragms using variations in ohmic resistance of piezoresistive elements integral with a semiconducting diaphragm
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
- G01L9/0041—Transmitting or indicating the displacement of flexible diaphragms
- G01L9/0042—Constructional details associated with semiconductive diaphragm sensors, e.g. etching, or constructional details of non-semiconductive diaphragms
Definitions
- the invention relates to a pressure sensor chip for measuring a differential pressure.
- Differential pressure sensors are used to detect a pressure difference between a first and a second pressure acting on the sensor and are used for example in industrial metrology pressure gauges. There they are used for example for level measurement or flow measurement.
- level measurement for example, the difference between a first pressure acting down in a container and a second pressure prevailing above the contents is measured. The difference is proportional to a level-dependent hydrostatic pressure in the tank and thus to the level.
- flow measurement for example, a flow resistance is used in a line and determined by means of a Differenzdruckmessaufillons a difference of a prevailing before the first resistance and a pressure prevailing behind the resistance second pressure. This differential pressure is a measure of the flow through the pipe.
- System pressure here refers to the outlet pressure to which the pressure difference is superimposed.
- the system pressure is the lower of the two pressures whose difference is to be measured.
- Differential pressure sensor chips comprise a differential pressure measuring diaphragm, one side of which is subjected to a first pressure during measuring operation and the second side to a second pressure.
- the applied pressures cause a resulting deflection of the differential pressure measuring diaphragm, which corresponds to the differential pressure to be measured.
- Pressure sensor chips are usually very sensitive and are therefore not directly exposed to a medium whose pressure is to be recorded. Instead, with a liquid filled diaphragm seals are connected upstream.
- a force acting on the measuring diaphragm differential pressure causes a differential pressure dependent deflection of the differential pressure measuring diaphragm, which detects by means of the piezoresistive elements, and converted into an electrical signal that is then a further processing and / or evaluation available.
- BESOI wafers bonded and etched silicon on insulator
- BESOI wafers are manufactured using silicon direct bonding.
- two oxidized silicon wafers are aligned against each other and bonded under pressure and high temperature. This results in a three-layered wafer, in which there is an oxide layer between two silicon layers.
- the buried oxide layer known as BOX (buried oxide layer) has a thickness of a few nm to a few ⁇ m. This composite is thinned and polished from one side. The thinned polished side subsequently forms the active layer.
- the active layer may be a few microns thick and is known in the English speaking art e.g. referred to as device wafer or as silicone overlayer (SOL).
- SOL silicone overlayer
- a major advantage of using BESOI wafers for the manufacture of pressure sensors is that the buried Oxide layer (BOX) forms a reliable etch stop. This is used primarily for the production of movable electrodes of capacitive pressure sensors.
- BOX buried Oxide layer
- the remaining after the etching outer edge of the silicon layer bounds the recess on the outside and forms a support for the exposed through the recess membrane. After this etching process, the area of the oxide layer serving as an etching stop is removed by a further etching process.
- the piezoresistive elements are for example a positive doping elements, which are applied to a silicon layer having a negative doping.
- a silicon layer having a negative doping As a result, there is a pn junction between the p-doped piezoresistive elements and the silicon layer, which results in that the temperature range in which these pressure sensor chips can be used is limited.
- above temperatures of about 125 ° C sufficient electrical insulation between the piezoresistive elements and the substrate on which they are arranged is no longer guaranteed.
- the object of the invention is a process for the preparation of this
- the invention consists in a pressure sensor chip for measuring a differential pressure with [0014] a carrier made of silicon, an oxide layer arranged on the carrier, a silicon layer arranged on the oxide layer, [0017] ] - an insulating layer arranged on the silicon layer, and - a recess provided in the support which exposes a region of the oxide pressure layer, silicon layer and insulating layer which adjoins [0019] a differential pressure measuring membrane, - whose deflection, which is dependent on a differential pressure acting on it, is detected by at least one piezoresistive element, in that on the side of the insulating layer of the differential pressure measuring diaphragm facing away from the recess is arranged. [0025] According to a first development of the invention, the carrier made of silicon, an oxide layer arranged on the carrier, a silicon layer arranged on the oxide layer, [0017] ] - an insulating layer arranged on the silicon layer, and - a recess provided in the support which exposes
- Pressure sensor chip additionally designed as a system pressure sensor
- the oxide layer is arranged, [0027] on the oxide layer the silicon layer is arranged, [0028] on the silicon layer the insulating layer is arranged, and [0029] in the oxide layer one of the Differential pressure measuring membrane spaced recess is provided, which on its [0031] side facing away from the carrier of a one
- the first development extends through the oxide layer, the silicon layer and the insulating layer, a section through which the differential pressure measuring membrane is mechanically decoupled from the system pressure measuring diaphragm.
- the system pressure measuring diaphragm has a cylindrical opening arranged in its center, which is closed by a plug which extends through the opening and the recess in the oxide layer to the carrier and a spacer between the carrier and the system pressure measuring diaphragm forms.
- an electronics is arranged on the side facing away from the carrier top of the pressure sensor chip, to which the arranged on the insulating layer piezoresistive elements are connected.
- the piezoresistive elements for measuring the differential pressure and / or the piezoresistive elements for measuring the system pressure are each connected together to form a resistance bridge, and the electronics is used to a temperature that is exposed to the pressure sensor chip based derive an internal resistance of at least one resistance bridge and to provide compensation for temperature-dependent measurement error.
- the invention consists in a method for producing a pressure sensor chip according to the invention, in which
- the first silicon layer forms a support of silicon
- the differential pressure measuring diaphragm is arranged.
- the invention further comprises a first development of the method according to [0060] - in a region of the distance from the differential pressure measuring diaphragm
- Pressure sensor chip is formed a cylindrical opening which penetrates the insulating layer and the silicon layer, - through the opening a recess spaced from the differential pressure measuring membrane [0064] is etched into the oxide layer, which is referred to [0065] FIG ] whose side facing away from the carrier is closed by a region of the composite of silicon layer and insulating layer which forms a system pressure measuring membrane, the temperature of which depends on a system pressure acting on it
- piezoresisitive elements are generated by the silicon film is doped by implantation of ions, and a structuring of the doped silicon film is made in which only serving as piezoresistive elements regions of the doped silicon film remain on the insulating layer.
- the cylindrical opening is sealed under vacuum by deposition of at least one material, wherein a plug is built from the material, which extends through the opening and the recess in the oxide layer to the carrier and forms a spacer between the carrier and the system pressure measuring membrane.
- Deposition process carried out, in which at least one layer 33 of an insulating material on the side facing away from the carrier 1 surface of the pressure sensor chip with the piezoresisitive elements 13, 19 thereon is deposited, which is a primary passivation of the top of the pressure sensor chip and the thereon Piezoresistive elements causes.
- the pressure sensor according to the invention has the advantage that it can be used at high temperatures of up to 250 ° C.
- One reason for this is that the piezoresistive elements are electrically insulated by the insulating layer from the substrate on which they are located.
- the insulation layer provides reliable insulation even at high temperatures of up to 250 ° C.
- a further advantage is that the oxide layer arranged on the carrier serves as a reliable etch stop in the production of the recess through which the differential pressure measuring membrane is exposed.
- the oxide layer arranged on the carrier serves as a reliable etch stop in the production of the recess through which the differential pressure measuring membrane is exposed.
- thin differential pressure measuring membranes can be produced with a very homogeneous thickness over the entire surface of the membrane. This means that even very small differential pressures, esp. Differential pressures of less than 30 mbar can be detected with the pressure sensor chip of the invention high accuracy and reproducibility.
- Fig. 1 shows a section through a differential pressure sensor
- FIG. 2 shows a section through a differential pressure sensor and a
- FIG. 3 is a view of the pressure sensor chip of FIG. 2;
- FIG. Fig. 4 shows a section through a BESOI wafer with a thinned [0085] silicon layer;
- Fig. 5 shows an implantation of an insulating layer, which is a thin
- FIG. 6 shows a doping of the silicon film of Fig. 5 with boron
- FIG. 7 shows a surface of the pressure sensor chip structured to produce the piezoresistive elements
- FIG. Fig. 8 shows a recess in the carrier through which the
- Fig. 9 shows one for generating the system pressure measuring membrane in the
- Fig. 10 shows a recess etched through the aperture in the oxide layer, through which the system pressure sensing membrane is exposed;
- Fig. 11 shows a stopper closing the opening and a layer of insulator applied on the pressure sensor chip; and FIG. 12 shows a metallization applied to the pressure sensor chip, which causes electrical connection of the piezoresistive elements and forms contact pads for contacting the elements interconnected [0101].
- Fig. 1 shows a pressure sensor chip according to the invention.
- Pressure sensor chip is a differential pressure sensor that can be used in particular for measuring low differential pressures, in particular of differential pressures of less than 30 mbar, at high temperatures, in particular at temperatures of up to 250 ° C.
- FIG. 2 shows a section through a further development of the
- FIG. 3 shows a view of the top of the
- Pressure sensor chips of Fig. 2. This is a multifunctional pressure sensor chip, especially for measuring low differential pressures, in particular of differential pressures of less than 30 mbar, at high system pressures, in particular at system pressures of more than 100 bar, at high temperatures, in particular at temperatures of up to 250 ° C is usable.
- the pressure sensor chip comprises a region I designed as a differential pressure sensor and a region II designed as a system pressure sensor.
- the area I designed as a differential pressure sensor is identical to the differential pressure sensor shown in FIG. In the following, therefore, only the pressure sensor chip shown in FIGS. 2 and 3 will be described in detail.
- the description contained therein of the area I designed as a differential pressure sensor apply in identical form to the pressure sensor chip shown in FIG. 1 and is therefore not listed twice. The same applies in analogous form for the associated manufacturing process described below.
- Differential pressure sensor and a system pressure sensor it is very versatile.
- the integration of these two sensors in a single pressure sensor chip has the advantage that it is very compact and allows a compensation of system pressure dependent measurement errors of the differential pressure sensor.
- the measurement accuracy that can be achieved with the differential pressure sensor which can greatly depend on the system pressure, especially when measuring low differential pressures at high system pressures, can be significantly increased.
- the pressure sensor chip has a carrier 1 made of silicon, on which an oxide layer 3 is arranged.
- the carrier 1 is preferably a monocrystalline substrate with negative doping. Alternatively, however, it is also possible to use a monocrystalline substrate without doping or with positive doping.
- the oxide layer 3 is made of silicon dioxide (SiO 2 ).
- On the oxide layer 3 is another silicon layer 5, which preferably also has a negative doping. Alternatively, a monocrystalline substrate without doping or with positive doping can also be used here.
- an insulating layer 7 is arranged, which preferably also consists of silicon dioxide (SiO 2 ).
- the carrier 1 is formed in the as a differential pressure sensor
- a recess 9 is provided which exposes a differential pressure measuring diaphragm 11 forming region of the adjacent thereto composite of oxide layer 3, silicon layer 5 and insulating layer 7.
- the differential pressure measuring diaphragm 11 is exposed to a differential pressure, which causes a differential pressure-dependent deflection of the differential pressure measuring diaphragm 11.
- a first pressure p1 of the side facing away from the carrier 1 side of the differential pressure measuring diaphragm 11 is supplied.
- a second pressure p 2 is supplied through the recess 9 of the side facing the carrier 1 of the differential pressure measuring diaphragm 11.
- the differential pressure to be measured corresponds to the difference between the first and the second pressure p1, p2.
- the force acting on the differential pressure measuring diaphragm 11 differential pressure dependent deflection of the differential pressure measuring diaphragm 11 is detected by at least one piezoresistive element 13 that is arranged on the side facing away from the recess 9 side of the insulating layer 7 of the differential pressure measuring diaphragm 11.
- the insulating layer 7 causes an electrical insulation of the piezoresistive elements 13 with respect to the underlying silicon layer 5. This makes it possible to use the pressure sensor chip at high temperatures, esp. At temperatures up to 250 ° C.
- a plurality of piezoresistive elements 13 are provided for this purpose, which are interconnected to form a Wheatstone bridge.
- FIG. 3 shows four piezoresistive elements 13, which are shown here only schematically, and which are combined by a connection, not shown in the figures, to form a Wheatstone bridge.
- Wheatstone bridges have a temperature-dependent internal resistance, which can be determined via corresponding taps on the differential pressure measuring diaphragm 11, in a simple manner. This temperature-dependent internal resistance is then available Determining the temperature that is exposed to the pressure sensor chip is available. Based on the temperature compensation of temperature-dependent measurement errors of the differential pressure sensor can then be made. Likewise, based on the temperature compensation of temperature-dependent measurement errors of the system pressure sensor can be made.
- the system pressure sensor is located in the second area II of the
- a recess 15 is provided which is spaced from the differential pressure measuring diaphragm 11 and which faces away from the carrier 1 from a region of the composite of silicon layer 5 and forming a system pressure measuring diaphragm 17 Insulating layer 7 is completed.
- the system pressure p sys to be measured is supplied to the side facing away from the carrier 1 side of the system pressure measuring diaphragm 17, and causes a system pressure p sys dependent deflection thereof.
- at least one piezoresistive element 19 is likewise provided, that is arranged on the side of the insulating layer 7 of the system pressure measuring membrane 17 facing away from the recess 15.
- the insulating layer 7 causes an electrical insulation of the piezoresistive elements 19 with respect to the underlying silicon layer 5, which makes it possible to use the pressure sensor chip at high temperatures, esp. At temperatures up to 250 ° C.
- a plurality of piezoresistive elements 19 are also provided here, which are interconnected to form a Wheatstone bridge.
- FIG. 3 shows four piezoresistive elements 19, which are shown here only schematically, and which are connected together by a connection, not shown in the figures, to form a Wheatstone bridge.
- the temperature dependent internal resistance of the Wheatstone bridge can be detected and used to determine the temperature to which the pressure sensor chip is exposed. As a rule, it is sufficient to determine the temperature on the basis of one of the two pressure sensors integrated on the pressure sensor chip and for all desired compensations of temperature-dependent measuring errors.
- the section 21 is a longitudinal section, which separates the two regions I, Il of the pressure sensor chip from each other and leads into the carrier 1 into it.
- the system pressure measuring diaphragm 17 has a cylindrical opening disposed in the center thereof, which is closed by a plug 23 made of an insulator.
- the plug 23 extends through the opening and the recess 15 in the oxide layer 3 through to the carrier 1 and forms a spacer between the carrier 1 and the system pressure measuring diaphragm 17.
- the system pressure measuring diaphragm 17 is a rigid annular membrane, which is also at low Membrane thickness is able to take very high system pressures, for example system pressures of more than 100 bar.
- the thicknesses of the differential pressure measuring diaphragm 11 and the system pressure measuring diaphragm 17 can be identical even up to the thickness of the oxide layer 5, if the differential pressure measuring diaphragm 11 is designed for low differential pressures, especially for differential pressures of less than 30 mbar, and System pressure measuring diaphragm 17 for the detection of high system pressures, esp. Of system pressures of up to 100 bar, is designed.
- a differential pressure measuring diaphragm 11 with a size of 4 mm ⁇ 4 mm can be combined with a system pressure measuring diaphragm 17 with a diameter of 0.5 mm.
- an electronics 25 is arranged on the side facing away from the carrier 1 top of the pressure sensor chip, to which the piezoresistive elements 13 for measuring the differential pressure and the piezoresistive elements 19 for measuring the system pressure are connected.
- this electronics 25 is a simple amplifier circuit that processes the measurement signals for further processing and / or evaluation and provides them via a corresponding output. But it can also contain other signal processing and / or evaluation circuits. Examples include a circuit which is the temperature of the chip is exposed, based on the internal resistance of the Wheatstone bridge, and circuits for compensating temperature-dependent measurement errors of the two sensors and circuits for compensating a system pressure dependent measurement error of the differential pressure sensor.
- the invention further comprises a method for producing a pressure sensor chip according to the invention. This is explained in detail below with reference to the pressure sensor chip shown in FIGS. 2 and 3 for measuring the differential pressure and the system pressure. Since the pressure sensor chip of FIG. 1 is part of this embodiment, this description also contains the description of the corresponding manufacturing method for the pressure sensor chip according to the invention shown in FIG. 1, which exclusively comprises the differential pressure sensor. The production of this pressure sensor chip is therefore not listed again separately.
- the pressure sensor chip of the present invention is a silicon based semiconductor chip fabricated using silicon-on-insulator (SOI) technology.
- the starting material is a commercially available BESOI wafer (bonded and etched silicon on insulator).
- BESOI wafers are made from two oxidized silicon wafers, which are aligned and bonded under pressure and high temperature. This results in a three-layer wafer shown in FIG. 4, which has a first and a second silicon layer. Both layers have, for example, a negative doping and are designated in FIG. 4 with n-Si1 and n-Si2.
- the negative doping can be achieved for example by phosphorus.
- the two layers but also a positive doping or even have no doping.
- n-Si2 is the oxide layer 3.
- the known under the name BOX (buried oxide layer) buried oxide layer 3 has a thickness of a few nm to a few microns and consists for example made of silicon dioxide SiO 2 .
- This composite is thinned and polished from one side.
- the thinned polished side here the second layer n-Si2
- SOL silicone overlayer
- the thickness of this layer can already be produced very accurately and uniformly and with high reproducibility using today's production methods.
- the first silicon layer n-Si1 forms the carrier 1 of the pressure sensor chip.
- the insulating layer 7 and an overlying thin monocrystalline silicon film 27 covering the insulating layer 7 are formed.
- the implantation of the ions is shown in FIG. 5 by arrows.
- the implantation energy is preferably between 100 keV and 1000 keV.
- the structure is tempered at a temperature of 1150 ° C to 1400 ° C. Implantation and subsequent annealing can be repeated several times. This results in the formation of an insulating layer 7 of silicon dioxide or silicon nitride arranged on the silicon layer 5, which is covered by the thin silicon film 27.
- Oxygen implantation is known by the name Separation by implantation of oxygen (SIMOX).
- SIMOX Separation by implantation of oxygen
- the SIMOX technology makes it possible to produce the thin silicon film 27 with a thickness which can be precisely set and reproduced to within 5 nm.
- the thickness of the silicon film 27 is preferably less than 500 nm.
- the thin silicon film 27 becomes the piezoresistive elements 13, 19 generates.
- This is preferably done by doping the silicon film 27 in a first operation by implantation of ions.
- a positive doping is carried out in the silicon film 27 located on the insulating layer 7. This can be done, for example, as shown in Fig. 6 symbolically by arrows, by the implantation of boron. This results in the thin silicon film 27, a homogeneous layer 29 with uniform positive doping.
- a structuring of the homogeneous layer 29 is carried out, in which only the areas of the layer 29 serving as piezoresistive elements 13, 19 remain on the insulating layer 7.
- the remaining areas of the layer 29 are removed during structuring.
- the structuring takes place for example by means of dry etching.
- a plasma etching as it is known for example under the name Reactive Ion Etching (RIE).
- RIE Reactive Ion Etching
- the temperature coefficients of the resistances of these piezoresistive elements 13, 19 and the temperature coefficients of the piezoresistive constants of the piezoresistive elements 13, 19 are decisively determined by the dose used for the last implantation, here the boron.
- the dimensions of the piezoresistive elements 13, 19 are selected as a function of these parameters.
- a desired resistance of the piezoresistive element 13, 19 can be targeted be set.
- Differential pressure measuring diaphragm 11 produced.
- the recess 9 is etched into the carrier 1.
- an anisotropic wet-chemical etching method in particular using a KOH etching solution, can be used.
- the buried oxide layer 3 of the BESOI wafer serves as a reliable etch stop.
- the region of the adjacent composite of oxide layer 3, silicon layer 5 and insulating layer 7 that forms the differential pressure measuring diaphragm 11 is uncovered.
- a deflection of the differential pressure measuring membrane 11 which is dependent on a differential pressure acting thereon is detected by at least one of the piezoresistive element 13 as described above in connection with the pressure sensor chip according to the invention with reference to FIG. 2, that on the side facing away from the recess 9 Side of the differential pressure measuring diaphragm 11 is arranged.
- the pressure sensor chip shown in Fig. 1 the pressure sensor chip shown in Fig. 1.
- the system pressure sensor is generated in the second area II.
- US-A 5 510 276 relates to a piezoresistive pressure sensor chip and related manufacturing method.
- Starting material there is a silicon substrate with negative doping in the top side by an implantation of oxygen ions and subsequent annealing an oxide layer is introduced, which is covered by a silicon film.
- On the silicon film is epitaxially deposited another silicon layer with negative doping.
- the piezoresistive elements are produced by forming in the regions of the further silicon layer, which subsequently form the piezoresistive elements, a positive doping limited to these regions, e.g. by boron, is introduced.
- a cylindrical opening 28 is created in a region II of the pressure sensor chip which is at a distance from the differential pressure measuring diaphragm 11 and penetrates the insulating layer 7 and the silicon layer 5. This is shown in FIG. 9.
- the opening 28 is centered between the for measuring the System pressure p sys provided piezoresistive elements 19 arranged.
- classical photolithography methods which are preferably used in conjunction with a plasma etching or an ion etching, for example a reactive ion etching (RIE), are suitable for the production of the opening 28.
- the buried oxide layer 3 of the BESOI wafer just as in the generation of the differential pressure measuring membrane 11 exposing recess 9, serves as an etch stop.
- a recess 29 spaced from the differential pressure measuring diaphragm 11 is etched into the oxide layer 3 through the opening 28.
- the oxide layer 3 forms a sacrificial layer in this area, which is preferably removed by means of a selective etching solution, for example based on hydrofluoric acid (HF).
- HF hydrofluoric acid
- This lateral etching is perfectly reproducible and has a speed of the order of 1 ⁇ m / min at room temperature.
- the recess 29 is on its side facing away from the carrier 1 side of a system pressure measuring membrane 17 forming region of the composite of silicon layer 5 and insulating layer 7 completed.
- a deflection which is dependent on a system pressure p sys acting on the system pressure measuring diaphragm 17 is detected by the piezoresistive element 19, which are arranged on the side of the insulating layer 7 of the system pressure measuring diaphragm 17 facing away from the recess 29.
- the recess 29 is evacuated and the opening 28 is closed under vacuum.
- the opening 28 is closed by a deposition of a material, wherein from the material, a plug 31 is constructed, which extends through the opening 28 and the recess 29 in the oxide layer 5 through to the carrier 1.
- the plug 31 hermetically seals the opening 28 and forms a spacer between the carrier 1 and the system pressure measuring diaphragm 17.
- the plug 31 turns the system pressure measuring diaphragm 11 into a rigid annular diaphragm. This makes it possible even with relatively thin system pressure measuring membranes 11 to detect high static pressures of up to 100 bar.
- the material is preferably an insulating material, such as. B.
- the plug 31 is made up of layers of silicon dioxide (SiO 2 ) and silicon nitride (Si 3 N 4 ) deposited on one another.
- the deposition of the material or the material layers is preferably carried out by chemical vapor deposition under vacuum (LPCVD) or by plasma enhanced chemical vapor deposition (PECVD). In this case, for example, classic photolithographic methods can be used to limit the deposition to the region of the opening 28.
- At least one deposition process is carried out in which at least one layer 33 of an insulating material is deposited on the surface of the pressure sensor chip facing away from the carrier 1 with the piezoresisitive elements 13, 19 thereon.
- a small area 34 is preferably recessed in the immediate vicinity of each piezoresistive element 13, 19, in which subsequently an electrical contacting of the piezoresistive elements 13, 19 can take place.
- the regions 34 may be e.g. be covered by corresponding photolithographic processes by means of appropriately shaped masks during the deposition, which are then subsequently removed again. In principle, it would also be possible to provide the entire chip with the layer, and to subsequently remove these in the areas 34. However, this may be difficult depending on the material and may result in damage to the surface of the chip in the affected areas 34.
- the large-area deposition of the layer 33 on the chip surface has the advantage that it causes a primary passivation of the chip surface and esp.
- the passivation forms a protection of the piezoresistive elements 13, 19 from moisture and at the same time prevents a charge transport on the surface of the Pressure sensor chips.
- silicon nitride (Si 3 N 4 ) or silicon oxynitride (SION) is used to form the layer 33. These materials offer the advantage of providing additional shielding from electromagnetic radiation.
- the layer 33 preferably has a thickness of more than 50 nm. Ideally, the thickness of the layer 33 is between 80 nm and 100 nm.
- a metallization 35 is applied to the pressure sensor chip, by which an electrical interconnection of the piezoresistive elements 13, 19 is effected and contact pads for contacting the interconnected elements 13, 19 are generated.
- the contacting takes place in the previously recessed in the deposition of the layer 33 areas 34. This is shown in Fig. 12.
- a contacting material system suitable for use at high temperatures such as e.g. TiWN / Au used.
- the saw cut 21 already described above is then introduced into the pressure sensor chip, by means of which the differential pressure measuring diaphragm 11 is mechanically decoupled from the system pressure measuring diaphragm 17.
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Measuring Fluid Pressure (AREA)
- Pressure Sensors (AREA)
Abstract
L'invention concerne une puce de capteur de pression à usage le plus universel possible destinée à mesurer des pressions différentielles, laquelle peut être utilisée à des températures élevées. Elle comprend un support en silicium (1), une couche d'oxyde (3) disposée sur le support (1), une couche de silicium (5) disposée sur la couche d'oxyde (3), une couche isolante (7) disposée sur la couche de silicium (5) et un évidement (9) pratiqué dans le support (1). Cet évidement libère une zone formant une membrane (11) de mesure de pression différentielle du composé adjacent constitué de la couche d'oxyde (3), de la couche de silicium (5) et de la couche isolante (7), dont la déviation dépendant d'une pression différentielle appliquée sur celle-ci est détectée par au moins un élément piézorésistif (13) qui est disposé sur le côté de la couche isolante (7) de la membrane (11) de mesure de pression différentielle qui se trouve à l'opposé de l'évidement (9).
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102007014468.9 | 2007-03-22 | ||
DE102007014468A DE102007014468A1 (de) | 2007-03-22 | 2007-03-22 | Drucksensor-Chip |
Publications (1)
Publication Number | Publication Date |
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WO2008113707A1 true WO2008113707A1 (fr) | 2008-09-25 |
Family
ID=39541169
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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PCT/EP2008/052825 WO2008113707A1 (fr) | 2007-03-22 | 2008-03-10 | Puce de capteur de pression |
Country Status (2)
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DE (1) | DE102007014468A1 (fr) |
WO (1) | WO2008113707A1 (fr) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105403244A (zh) * | 2014-09-04 | 2016-03-16 | 横河电机株式会社 | 传感器装置、应变传感器装置及压力传感器装置 |
CN114061823A (zh) * | 2021-11-16 | 2022-02-18 | 杭州电子科技大学温州研究院有限公司 | 一种温度自补偿的高灵敏度压力传感器阵列及其制备方法 |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102012109325A1 (de) | 2012-10-01 | 2014-05-15 | Endress + Hauser Gmbh + Co. Kg | Drucksensor mit Deckschicht |
DE102014118850A1 (de) | 2014-12-17 | 2016-06-23 | Endress + Hauser Gmbh + Co. Kg | Drucksensor zur Messung eines Differenzdrucks und eines Systemdrucks |
US9967679B2 (en) | 2015-02-03 | 2018-05-08 | Infineon Technologies Ag | System and method for an integrated transducer and temperature sensor |
DE102015202423A1 (de) * | 2015-02-11 | 2016-01-14 | Robert Bosch Gmbh | Bauteil mit einer Wheatstone´schen Messbrücke für eine MEMS-Sensorfunktion |
CN112903087A (zh) * | 2021-01-18 | 2021-06-04 | 中国兵器工业集团第二一四研究所苏州研发中心 | Mems单片集成标矢量复合声波传感器及其加工方法 |
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US5259248A (en) * | 1990-03-19 | 1993-11-09 | Hitachi Ltd. | Integrated multisensor and static and differential pressure transmitter and plant system using the integrated multisensor |
US5444901A (en) * | 1993-10-25 | 1995-08-29 | United Technologies Corporation | Method of manufacturing silicon pressure sensor having dual elements simultaneously mounted |
US20050160827A1 (en) * | 2003-12-11 | 2005-07-28 | Proteus Biomedical, Inc. | Pressure sensors having transducers positioned to provide for low drift |
US20070013014A1 (en) * | 2005-05-03 | 2007-01-18 | Shuwen Guo | High temperature resistant solid state pressure sensor |
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US4975390A (en) * | 1986-12-18 | 1990-12-04 | Nippondenso Co. Ltd. | Method of fabricating a semiconductor pressure sensor |
FR2700003B1 (fr) | 1992-12-28 | 1995-02-10 | Commissariat Energie Atomique | Procédé de fabrication d'un capteur de pression utilisant la technologie silicium sur isolant et capteur obtenu. |
EP0672899B1 (fr) * | 1994-03-18 | 1999-10-06 | The Foxboro Company | Capteur semi-conducteur de pression avec membrane en silicium monocristallin et jauges de contraintes monocristaux et son procédé de fabrication |
US20010001550A1 (en) * | 1998-11-12 | 2001-05-24 | Janusz Bryzek | Integral stress isolation apparatus and technique for semiconductor devices |
US6952042B2 (en) * | 2002-06-17 | 2005-10-04 | Honeywell International, Inc. | Microelectromechanical device with integrated conductive shield |
-
2007
- 2007-03-22 DE DE102007014468A patent/DE102007014468A1/de not_active Withdrawn
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2008
- 2008-03-10 WO PCT/EP2008/052825 patent/WO2008113707A1/fr active Application Filing
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
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US5259248A (en) * | 1990-03-19 | 1993-11-09 | Hitachi Ltd. | Integrated multisensor and static and differential pressure transmitter and plant system using the integrated multisensor |
US5444901A (en) * | 1993-10-25 | 1995-08-29 | United Technologies Corporation | Method of manufacturing silicon pressure sensor having dual elements simultaneously mounted |
US20050160827A1 (en) * | 2003-12-11 | 2005-07-28 | Proteus Biomedical, Inc. | Pressure sensors having transducers positioned to provide for low drift |
US20070013014A1 (en) * | 2005-05-03 | 2007-01-18 | Shuwen Guo | High temperature resistant solid state pressure sensor |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105403244A (zh) * | 2014-09-04 | 2016-03-16 | 横河电机株式会社 | 传感器装置、应变传感器装置及压力传感器装置 |
CN105403244B (zh) * | 2014-09-04 | 2019-01-15 | 横河电机株式会社 | 应变传感器装置 |
CN114061823A (zh) * | 2021-11-16 | 2022-02-18 | 杭州电子科技大学温州研究院有限公司 | 一种温度自补偿的高灵敏度压力传感器阵列及其制备方法 |
CN114061823B (zh) * | 2021-11-16 | 2024-04-02 | 杭州电子科技大学温州研究院有限公司 | 一种温度自补偿的高灵敏度压力传感器阵列及其制备方法 |
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DE102007014468A1 (de) | 2008-09-25 |
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