CN104422550A - Capacitive pressure sensor and forming method thereof - Google Patents
Capacitive pressure sensor and forming method thereof Download PDFInfo
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- CN104422550A CN104422550A CN201310383322.4A CN201310383322A CN104422550A CN 104422550 A CN104422550 A CN 104422550A CN 201310383322 A CN201310383322 A CN 201310383322A CN 104422550 A CN104422550 A CN 104422550A
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Abstract
Provided are a capacitive pressure sensor and a forming method thereof. The capacitive pressure sensor comprises a substrate, a diaphragm covering the substrate and an etching hole, a first electrode and a second electrode which are opposite on two ends of the raised diaphragm, and a sealing layer on the back surface of the substrate. The substrate is provided with the etching hole which passes through the substrate. The part of the diaphragm on the etching hole is raised upward. A third cavity is between the upward raised diaphragm and the substrate. The third cavity and the etching hole form a second cavity. A first cavity is between the first electrode and the second electrode. The sealing layer seals the opening on the lower end of the second cavity. The area taken by the capacitive pressure sensor on the surface of the substrate is relatively small, so that integration level of a device is improved.
Description
Technical field
The present invention relates to micro electronmechanical field (MEMS), particularly a kind of capacitance pressure transducer, and forming method thereof.
Background technology
At present, the kind of pressure transducer mainly comprises pressure resistance type, piezoelectric type, condenser type, potentiometer type, inductance bridge formula, strain gage etc.Wherein, capacitive pressure transducer has high sensitivity, and the advantage be not easily affected by the external environment, commercially attracted attention gradually.
Because traditional pressure transducer exists that size is comparatively large, manufacture craft is more numerous and the restriction of the factor such as inconvenient operation.MEMS(Micro-Electro-Mechanical Systems, MEMS) technology is widely used making at pressure transducer.The pressure transducer that MEMS technology makes have microminiaturization, can low, the precision advantages of higher of batch making, cost, and can by pressure transducer and control circuit on the same base integrated, make the faint output signal of sensor can carry out amplification process nearby, avoid extraneous electromagnetic interference (EMI), improve the reliability of signal transmission.
With reference to the cross-sectional view that figure 1, Fig. 1 is existing capacitance pressure transducer.
As shown in Figure 1, described semiconductor pressure sensor comprises: semiconductor base 100; Be positioned at the doped region 104 of semiconductor base 100, described doped region 104 is for the bottom electrode as capacity plate antenna; Be positioned at the barrier film 103 above doped layer 104, barrier film 103 is as the top electrode of capacity plate antenna; Be positioned at the pedestal 101 semiconductor base 100 being supported described barrier film 103; Have cavity 102 between described barrier film 103 and doped region 104, barrier film 103, doped region 104 and cavity 102 form capacity plate antenna; Be arranged in the control circuit (not shown) of pedestal 101, described control circuit is electrically connected with capacity plate antenna.
When the barrier film 103 at above-mentioned capacity plate antenna applies testing pressure, or when there is pressure differential inside and outside barrier film 103, the middle body of barrier film 103 is under pressure and can produces deformation, thus change the capacitance of this capacity plate antenna, the variable quantity of this capacity plate antenna value can be detected, to obtain the change of pressure by control circuit.The computing formula of the capacitance of described capacity plate antenna is formula (1) C=ε S/d, wherein ε is the specific inductive capacity of the dielectric medium that cavity 102 is filled, S is that the right opposite between barrier film 103 and doped region 104 amasss, and d is the distance between barrier film 103 and doped region 104, and capacitance change (△ C=C-C
0) be formula (2) with the relational expression of pressure be F=PA=kd
0(△ C)/C
0, wherein F is the elastic force that capacity plate antenna is subject to, and k is the spring ratio of barrier film 103, d
0for the raw range between barrier film 103 and doped region 104, C
0for the initial capacitance of capacity plate antenna.Therefore capacitance change (the △ C=C-C of capacity plate antenna is measured by control module
0), just can obtain the pressure F that capacity plate antenna is subject to very easily.
But the surface area of the semiconductor base that existing capacitance pressure transducer, occupies is larger.
Summary of the invention
The problem that the present invention solves is the surface area reducing the substrate that capacitance pressure transducer, occupies.
For solving the problem, the invention provides a kind of formation method of capacitance pressure transducer, comprising: substrate is provided, in described substrate, forming etched hole; Form the first sacrifice layer on the substrate, described first sacrifice layer comprises fills the full Part I of etched hole and the Part II of cover part substrate surface, and Part I is positioned at immediately below Part II; Described first sacrifice layer and substrate form barrier film; Portion septum is formed the second sacrifice layer, and described second sacrifice layer is positioned at above the Part II of the first sacrifice layer; The both sides sidewall surfaces of described second sacrifice layer forms the first relative electrode and the second electrode, and described first electrode and the second electrode part are positioned at membrane surface; Remove described second sacrifice layer, form the first cavity between the first electrode and the second electrode; Planarization or etch the back side of described substrate, until expose the first sacrifice layer bottom etched hole; Remove described first sacrifice layer, form the second cavity in the bottom of barrier film; The back side of substrate is formed the sealant of the bottom opening of described second cavity of sealing.
Optionally, described second sacrifice layer width is less than the width of the Part II of the first sacrifice layer, and the length of the second sacrifice layer is equal to or less than the length of the first sacrifice layer Part II.
Optionally, the thickness of the Part II of described first sacrifice layer is 0.1 ~ 10 micron, and the width of the Part II of the first sacrifice layer is 0.1 ~ 10000 micron.
Optionally, the forming process of described first electrode and the second electrode is: form electrode material layer at the sidewall of described second sacrifice layer and the surface of surface and barrier film; Described electrode material layer forms mask layer, and described mask layer to cover on the second sacrifice layer both sides sidewall and electrode material layer on portion septum; Remove not by the electrode material layer that mask layer covers, the both sides sidewall surfaces of described second sacrifice layer forms the first relative electrode and the second electrode.
Optionally, described first electrode or the second electrode comprise Part I and Part II, and Part I is positioned at the both sides sidewall surfaces of the second sacrifice layer, and Part II is positioned at the surface of the barrier film on the top of the Part II of the first sacrifice layer and sidewall.
Optionally, described first electrode or the second electrode comprise Part I and Part II, Part I is positioned at the both sides sidewall surfaces of the second sacrifice layer, and Part II is positioned at the surface of barrier film on the top of the Part II of the first sacrifice layer and sidewall and the suprabasil membrane surface of the second sacrifice layer both sides.
Optionally, the spacing between the first electrode and the second electrode is 0.1 ~ 10000 micron.
Optionally, the width of described etched hole is less than the width of the first sacrifice layer Part II, and the degree of depth of described etched hole is for being greater than 50 microns, and width is 0.1 ~ 10000 micron.
Optionally, described first sacrifice layer or the second sacrificial layer material have high etching selection ratio relative to substrate, barrier film, the first electrode and the second electrode material.
Optionally, the material of described first sacrifice layer or the second sacrifice layer is bottom antireflective coating, polysilicon, amorphous silicon, agraphitic carbon, SiN, SiON, SiCN, SiC, BN, SiCOH, BN or SiGe.
Optionally, also comprise: formation control circuit and interconnection structure on other regions or other substrates of described substrate, the first electrode is connected with control circuit by interconnection structure with the second electrode.
Optionally, the thickness of described barrier film is 0.1 ~ 10 micron.
Present invention also offers a kind of capacitance pressure transducer, comprising: substrate, be arranged in substrate and run through the etched hole of its thickness; Cover the barrier film of described substrate and etched hole, and the portion septum above etched hole raises up, have the 3rd cavity between the barrier film raised up and substrate, the 3rd cavity and etched hole form the second cavity; Be positioned at the first relative electrode and the second electrode on protruding barrier film two ends, there is between the first electrode and the second electrode the first cavity; Be positioned at the sealant on the back side of substrate, sealant seals the opening of the second cavity lower end.
Optionally, the height of described 3rd cavity is 0.1 ~ 10 micron, and width is 0.1 ~ 10000 micron.
Optionally, the spacing between the first electrode and the second electrode is 0.1 ~ 10000 micron.
Optionally, the width of described 3rd cavity is greater than the width of etched hole.
Optionally, described first electrode or the second electrode comprise Part I and Part II, and Part I is positioned at the both sides of the first cavity, and Part II is positioned at top and the sidewall surfaces of the bossing of barrier film.
Optionally, described first electrode or the second electrode comprise Part I and Part II, and Part I is positioned at the both sides of the first cavity, and Part II is positioned in the substrate of the top of the bossing of barrier film and the bossing both sides of sidewall surfaces and barrier film.
Optionally, other regions of described substrate or other substrates also have control circuit and interconnection structure, and the first electrode is connected with control circuit by interconnection structure with the second electrode.
Optionally, the thickness of described barrier film is 0.1 ~ 10 micron.
Compared with prior art, technical scheme of the present invention has the following advantages:
Capacitance pressure transducer, of the present invention comprises protruding barrier film, is positioned at the first relative electrode and the second electrode on protruding barrier film two ends, has the first cavity between the first electrode and the second electrode.Top electrode and the bottom electrode of semiconductor base is parallel to compared to two of capacitance pressure transducer, of prior art, the surface of the first electrode and the second electrode vertical and substrate in the present invention, the surface area of the substrate that the first electrode and the second electrode are occupied reduces, save the area that capacitance pressure transducer, occupies, thus be conducive to the integrated level improving device.
Further, described first electrode or the second electrode comprise Part I and Part II, and Part I is positioned at the both sides sidewall surfaces of the second sacrifice layer, and Part II is positioned at the surface of the barrier film on the Part II top of the first sacrifice layer and sidewall.The Part II of the first electrode or the second electrode contacts with the membrane surface on the Part II top of the first sacrifice layer and sidewall, contact area is larger, improve contact adhesion and the physical strength of the first electrode or the second electrode and barrier film, effectively prevent coming off or being out of shape of the first electrode or the second electrode.
The formation method of capacitance pressure transducer, of the present invention, its formation process is simple, the integrated level of the capacitance pressure transducer, formed is higher, in addition, by substrate is carried out thinning after, remove the first sacrifice layer from the direction of separator bottom, make barrier film bossing keep integrality, make barrier film keep stronger physical strength and larger pressure can be born, improve the performance of capacitance pressure transducer.
Accompanying drawing explanation
Fig. 1 is the cross-sectional view of the capacitance pressure transducer, of prior art;
Fig. 2 ~ Figure 11 is the cross-sectional view of embodiment of the present invention capacitance pressure transducer, forming process.
Embodiment
Existing capacitance pressure transducer, adopts capacity plate antenna as sensing element, with reference to figure 1, the capacity plate antenna that MEMS technology makes comprises doped region 104(bottom electrode), relative with doped region 104 barrier film 103(top electrode) and cavity 103(dielectric medium between doped region 104 and barrier film 103).
Sensitivity is the important indicator of the performance weighing capacitance pressure transducer, barrier film 103(top electrode) area or barrier film 103 and doped region 104(bottom electrode) between right opposite to amass S be parameter sensitivity to material impact, in general, barrier film 103 under condition of equivalent thickness, barrier film 103(top electrode) area larger, can make the area in pressure sensitive face can be larger, the sensing of barrier film 103 pairs of pressure can be more responsive, barrier film 103 can be sensitiveer with the change of doped region 104 distance, thus improve the sensitivity of capacitance pressure transducer.Although the increase area of barrier film 103 or the right opposite between barrier film 103 and doped region 104 amass the sensitivity that S can improve capacitance pressure transducer, but the surface area that the right opposite increasing barrier film 103 and doped region 104 to a certain extent amasss the semiconductor base that capacitance pressure transducer, can be made to occupy increases, and is unfavorable for the raising of the integrated level of device.Therefore, adopt the capacitance pressure transducer, sensitivity of capacity plate antenna and can detected pressures scope need to improve.
The invention provides a kind of capacitance pressure transducer, and forming method thereof, wherein said capacitance pressure transducer, comprises protruding barrier film, be positioned at the first relative electrode and the second electrode on protruding barrier film two ends, there is between the first electrode and the second electrode the first cavity.Compared to two top electrode and the bottom electrodes being parallel to semiconductor base of the capacitance pressure transducer, of prior art, the surface of the first electrode and the second electrode vertical and substrate in the present invention, the surface area of the substrate that the first electrode and the second electrode are occupied reduces, save the area that capacitance pressure transducer, occupies, thus be conducive to the integrated level improving device.
For enabling above-mentioned purpose of the present invention, feature and advantage more become apparent, and are described in detail specific embodiments of the invention below in conjunction with accompanying drawing.When describing the embodiment of the present invention in detail, for ease of illustrating, schematic diagram can be disobeyed general ratio and be made partial enlargement, and described schematic diagram is example, and it should not limit the scope of the invention at this.In addition, the three-dimensional space of length, width and the degree of depth should be comprised in actual fabrication.
Fig. 2 ~ Figure 11 is the cross-sectional view of embodiment of the present invention capacitance pressure transducer, forming process.
With reference to figure 2, provide substrate 200, in described substrate 200, form etched hole 201.
Described substrate 200 is as the carrier of follow-up formation capacitance pressure transducer.
Substrate 200 described in substrate 200 substrate 200 can be single or multiple lift stacked structure.When described substrate 200 is multilayer lamination structure, such as: when described substrate is double stacked structure, described substrate comprises Semiconductor substrate and is positioned at the dielectric layer of semiconductor substrate surface, or described substrate comprises first medium layer and is positioned at the second dielectric layer on first medium layer surface.
Substrate 200 described in the present embodiment is double stacked structure, comprising: Semiconductor substrate and the dielectric layer be positioned in Semiconductor substrate, and Semiconductor substrate can be silicon substrate, germanium substrate, silicon-Germanium substrate, silit; The substrate of silicon-on-insulator substrate, germanium substrate on insulator, gallium arsenide substrate or other etchings, described dielectric layer material can be SiO
2, SiN, SiON or SiCN etc.In the present embodiment, described Semiconductor substrate is silicon substrate, and the material of described dielectric layer is SiO
2, described etched hole 201 runs through dielectric layer, and part is arranged in Semiconductor substrate.
Described etched hole 201 as passage during follow-up removal the first sacrifice layer, the degree of depth D1 of described etched hole 201 is greater than 50 microns, the width W 2 of etched hole 201 can be 0.1 ~ 10000 micron, and the width of etched hole 201 is less than the width of the Part II of the first sacrifice layer of follow-up formation.It should be noted that described etched hole can be other suitable degree of depth or width.
With reference to figure 3, described substrate 200 is formed the first sacrifice layer 202, described first sacrifice layer 202 comprises fills full etched hole 201(with reference to figure 2) Part I 21 and the Part II 22 on cover part substrate 200 surface, Part I 21 is positioned at immediately below Part II 22.It should be noted that, in accompanying drawing 3 and subsequent drawings, in order to distinguish conveniently, separate with dotted line between Part I and Part II.
The forming process of described first sacrifice layer 202 is: in described substrate 200, form the first sacrificial material layer, and the first sacrificial material layer fills full etched hole 201; Form mask layer on the first sacrificial material layer surface, described mask layer has the opening on the part of substrate surface exposing etched hole both sides; Remove suprabasil part first sacrificial material layer along opening etching, form the first sacrifice layer 202.
The Part II 22 of the first sacrifice layer 202 is higher than the surface of substrate 200, and follow-up can formation on a substrate 200 has protruding barrier film, and forms the second cavity after follow-up removal first sacrifice layer 202.
The material of described first sacrifice layer 202 has high etching selection ratio relative to the first electrode of substrate 200, barrier film 203 and follow-up formation and the second electrode material.
The material of described first sacrifice layer 202 can be bottom antireflective coating, polysilicon, amorphous silicon, agraphitic carbon, SiN, SiON, SiCN, SiC, BN, SiCOH, BN or SiGe.In the present embodiment, the material of described first sacrifice layer 202 is bottom antireflective coating.
The thickness T1 of the Part II 22 of described first sacrifice layer 202 can be 0.1 ~ 10 micron, and the width W 1 of Part II 22 can be 0.1 ~ 10000 micron, and the width W 1 of Part II 22 is greater than the width of etched hole.It should be noted that the Part II of described first sacrifice layer can be other suitable thickness or width.
With reference to figure 4, described first sacrifice layer 202 and substrate 200 form barrier film 203.
Described barrier film 203 is as the pressure sensitive film of capacitance pressure transducer.
Described barrier film 203 is fine and close insulating dielectric materials, such as: SiN, SiON, SiCN, SiC or BN or other suitable materials.In the present embodiment, the material of described barrier film 203 is SiN.
Portion septum 203 above the Part II 22 of the first sacrifice layer 202 is raised in substrate 200 surface, follow-up after removal first sacrifice layer, the second cavity can be formed between barrier film 203 and substrate 200, after forming the second cavity, the bossing of barrier film 203 contacts with substrate 200 surface of surrounding, improve the physical strength of barrier film 203, make barrier film 203 can bear larger pressure.
The thickness of described barrier film 203 is 0.1 ~ 10 micron, makes barrier film 203 have higher physical strength.It should be noted that described barrier film can be other suitable thickness.
Then, with reference to figure 5, portion septum 203 forms the second sacrifice layer 204, and described second sacrifice layer 204 is positioned at above the Part II 22 of the first sacrifice layer 202.
Directly over the Part II 22 that described second sacrifice layer 204 is positioned at the first sacrifice layer 202 (or being positioned at the part surface of protruding barrier film 203), the width of described second sacrifice layer 204 is less than the width of the Part II 22 of the first sacrifice layer 202, the length of the second sacrifice layer 204 equals the length of the first sacrifice layer Part II, follow-uply on the both sides sidewall of the second sacrifice layer 204, form the first relative electrode and the second electrode, the width of the second sacrifice layer 204 determines the distance between the first electrode of follow-up formation and the second electrode.It should be noted that, the width of the width of described second sacrifice layer 204 and the Part II 22 of the first sacrifice layer 202 refers to size along the x-axis direction, and the length of the length of the second sacrifice layer 204 and the Part II 22 of the first sacrifice layer 202 refers to size along the y-axis direction.
The material of described second sacrifice layer 204 has high etching selection ratio relative to substrate 200, barrier film 203, first electrode and the second electrode material, follow-up when removal the second sacrifice layer 204, can prevent from causing damage or over etching to substrate 200, barrier film 203, first electrode and the second electrode material etc.Concrete, the material of described second sacrifice layer 204 is bottom antireflective coating, polysilicon, amorphous silicon, agraphitic carbon, SiN, SiON, SiCN, SiC, BN, SiCOH, BN or SiGe.In the present embodiment, the material of described second sacrifice layer 204 is agraphitic carbon.
The shape of described second sacrifice layer 204 is the spatial structure at least with both sides parallel side, follow-uply can form the first electrode and the second electrode respectively in two parallel side of spatial structure, described parallel side can be parallel plane, parallel cambered surface, parallel surfaces etc.Parallel side be parallel cambered surface or parallel surfaces time make the first electrode of follow-up formation and the second electrode accordingly also for parallel cambered surface or parallel surfaces, compared to plane electrode, increase the size that the right opposite of electrode is long-pending, thus increase the size of electric capacity, be conducive to the sensitivity improving capacitance pressure transducer.
In the present embodiment, the shape of described second sacrifice layer 204 is for having two plane-parallel cubes, and its formation process is simple, and technique burden is less.
Then, with reference to figure 6 and Fig. 7, electrode material layer 205 is formed at the sidewall of described second sacrifice layer 204 and the surface of surface and barrier film 203; Described electrode material layer 205 forms mask layer 206, and described mask layer 206 to cover on the second sacrifice layer 204 both sides sidewall and electrode material layer 205 on portion septum 203.
Follow-up the first electrode for the formation of capacitance pressure transducer, of described electrode material layer 205 and the second electrode, the formation process of electrode material layer 205 is deposition or sputtering.
Described electrode material layer 205 can be Al, Cu, Ag, Au, Pt, Ni, Ti, TiN, TaN, Ta, TaC, TaSiN, W, WN or Wsi.
Described electrode material layer 205 can be single or multiple lift stacked structure.
In the present embodiment, electrode material layer 205 is single layer structure, and the material of electrode material layer 205 is TiN, and form the technique of electrode material layer 205 for sputtering, the thickness of electrode material layer 205 is 0.1 ~ 10 micron.
Described mask layer 206 to cover on the second sacrifice layer 204 both sides sidewall and electrode material layer 205 on portion septum 203, mask layer 206 has opening, the electrode material layer that described opening exposes the partial sidewall (two opposite side walls of arranging along the y-axis direction) of the second sacrifice layer 204 top surface and the second sacrifice layer and the electrode material layer be positioned in substrate 200.
The material of described mask layer 206 can be photoresist.
Then, with reference to figure 8, remove not by mask layer 206(with reference to figure 7) electrode material layer 205 that covers, the both sides sidewall surfaces of described second sacrifice layer 204 is formed the first relative electrode 207 and the second electrode 208.
The technique removing described electrode material layer 205 is dry etching, in the present embodiment, adopt fluorine-containing plasma etching remove not by mask layer 206(with reference to figure 7) electrode material layer 205 that covers.
In the present embodiment, described first electrode 207 or the second electrode 208 comprise Part I and Part II, Part I is positioned at the both sides sidewall surfaces of the second sacrifice layer 208, and Part II is positioned at the surface of the barrier film on Part II 22 top of the first sacrifice layer 202 and sidewall.After follow-up removal second sacrifice layer 204, the Part I of the first electrode 207 or the second electrode 208 is perpendicular to barrier film 203 surface (or substrate 200 surface), Part II is formed Part I and supports, and, first electrode 207 or the Part II of the second electrode 208 contact with barrier film 203 surface on Part II 22 top of the first sacrifice layer 202 and sidewall, contact area is larger, improve contact adhesion and the physical strength of the first electrode 207 or the second electrode 208 and barrier film 203, effectively prevent coming off or being out of shape of the first electrode 207 or the second electrode 208.
In other embodiments of the invention, described first electrode or the second electrode comprise Part I and Part II, Part I is positioned at the both sides sidewall surfaces of the second sacrifice layer, Part II is positioned at the surface of barrier film on the Part II top of the first sacrifice layer and sidewall and the suprabasil membrane surface of the second sacrifice layer both sides, further increases the first electrode or the second electrode contact adhesion and physical strength.
Then, please refer to Fig. 9, remove described second sacrifice layer 204(with reference to figure 8), between the first electrode 207 and the second electrode 208, form the first cavity 209.
The technique removing described second sacrifice layer is dry method or wet-etching technology, in the embodiment of the present invention, adopts and removes described second sacrifice layer 204 containing ammonia plasma treatment.
After removing described second sacrifice layer 204, make to form the first cavity 209 between the first electrode 207 and the second electrode 208, the two ends of what the first electrode 207 was relative with the second electrode 208 be positioned at protruding barrier film, compared to two electrode runs parallel of existing electric capacity in the surface of substrate, in the present invention, the first electrode 207 and the second electrode 208 are perpendicular to the surface of substrate 200, the surface area of the substrate 200 occupied bottom the first electrode 207 and the second electrode 208 is relatively little, thus can improve the integrated level of device.
In other embodiments of the invention, the step of described removal second sacrifice layer 204, at planarization or the back etching substrate 200, is carried out after exposing the first sacrifice layer 202 bottom etched hole.
Finally, with reference to Figure 10 and Figure 11, the back side of substrate 200 described in planarization, until the first sacrifice layer 202 exposing bottom etched hole; Remove described first sacrifice layer 202, form the second cavity 210 in the bottom of barrier film 203; The back side of substrate 200 is formed the sealant 211 of the bottom opening of described second cavity 210 of sealing.
Remove the Part I 21(of the first sacrifice layer 201 with reference to figure 8) correspondingly afterwards form etched hole 201, remove the Part II 22(of the first sacrifice layer 201 with reference to figure 8) corresponding formation the 3rd cavity 23 afterwards, etched hole 201 and the 3rd cavity 23 form the second cavity 210.In the embodiment of the present invention, by substrate 200 is carried out thinning after, the first sacrifice layer 202 is removed from the direction bottom barrier film 203, the bossing of barrier film 203 is made to keep integrality, make barrier film keep stronger physical strength and larger pressure can be born, improve the performance of capacitance pressure transducer.
The technique at the back side of planarization of substrates 200 is cmp, until expose the first sacrifice layer 202 bottom etched hole.
In other embodiments of the invention, also can etch the back side of substrate, form the second etched hole, the second etched hole exposes the first sacrifice layer bottom etched hole; Remove the first sacrifice layer by the second etched hole, form the second cavity.
Described sealant 211 is fine and close insulating dielectric materials, such as: SiN, SiON, SiCN, SiC, BN or macromolecule resin etc.In the embodiment of the present invention, adopt low-pressure chemical vapor deposition process to form sealant 211, make the environment in the second cavity 210 keep low pressure.
In other embodiments of the invention, described sealant 211 can be silicon substrate, silicon nitrate substrate or silicon-Germanium substrate, can adopt bonding technology that sealant 211 is bonded together with the back side of substrate 200, thus close the opening of the second cavity 210 lower end.Bonding technology can be anode linkage, glass paste bonding and silicon direct bonding, low temperature eutectic bonding, metal diffusion (congruent melting is brilliant) bonding etc.
Also comprise: in other region formation control circuit and interconnection structure (not shown)s of described substrate 200, the first electrode 207 is connected with control circuit by interconnection structure with the second electrode 208.Described control circuit is for receiving, process and transmitting the signal that electric capacity exports.In the present embodiment, can in the Semiconductor substrate of substrate 200 formation control circuit; Then form dielectric layer on a semiconductor substrate, dielectric layer and Semiconductor substrate form substrate 200; Then capacitance pressure transducer, is made in the dielectric layer; And then make interconnection structure in dielectric layer, by capacitance pressure transducer, and control circuit adjacent.
In other embodiments of the invention, can also at the upper formation control circuit of the second substrate (or second Semiconductor substrate), after capacitance pressure transducer, is formed, etched hole interconnection structure (interconnection structure) is formed in substrate 100, then by stacking with the substrate with control circuit for the substrate 100 with capacitance pressure transducer, by etched hole interconnection structure (interconnection structure) by control circuit and capacitance pressure transducer, electrical connection.
After formation second cavity 210, first electrode 207, second electrode 208 and the first cavity 209 form pressure sensing capacitance, when described barrier film 203 can be out of shape up or down when being under pressure (such as hydraulic pressure or air pressure etc.), the distance between the first electrode 207 and the second electrode 208 is made to increase or reduce, the capacitance of pressure sensing capacitance changes, control circuit receives pressure sensing capacitance output signal, and processes signal, obtains the pressure size and Orientation that barrier film 203 is subject to.
The capacitance pressure transducer, that above-mentioned direction is formed, please refer to Figure 11, comprising:
Substrate 200, is arranged in substrate 200 and runs through the etched hole 201 of its thickness;
Cover the barrier film 203 of described substrate 200 and etched hole 201, and the portion septum 203 above etched hole 201 raises up, there is between the barrier film 203 raised up and substrate 200 the 3rd cavity the 23, three cavity 23 and etched hole 201 forms the second cavity 210;
To be positioned on protruding barrier film 203 two ends the first relative electrode 207 and between the second electrode 208, first electrode 207 and the second electrode 208, to there is the first cavity 209;
Be positioned at the sealant 211 on the back side of substrate 200, sealant 211 seals the opening of the second cavity 210 lower end.
Concrete, the height of described 3rd cavity 23 is 0.1 ~ 10 micron, and width is 0.1 ~ 10000 micron, and the width of the 3rd cavity 23 is greater than the width of etched hole 201.
Spacing between first electrode 207 and the second electrode 208 is 0.1 ~ 10000 micron.
In the present embodiment, described first electrode 207 or the second electrode 208 comprise Part I and Part II, and Part I is positioned at the both sides of the first cavity 209, and Part II is positioned at top and the sidewall surfaces of the bossing of barrier film 203.The Part I of the first electrode 207 or the second electrode 208 is perpendicular to barrier film 203 surface (or substrate 200 surface), Part II is formed Part I and supports, and, first electrode 207 or the Part II of the second electrode 208 contact with the atop part of the bossing of barrier film and sidewall surfaces, contact area is larger, improve contact adhesion and the physical strength of the first electrode 207 or the second electrode 208 and barrier film 203, effectively prevent coming off or being out of shape of the first electrode 207 or the second electrode 208.
In other embodiments of the invention, described first electrode or the second electrode comprise Part I and Part II, Part I is positioned at the both sides of the first cavity, Part II is positioned at atop part and the sidewall surfaces of the bossing of barrier film, further increases the first electrode or the second electrode contact adhesion and physical strength.
Other regions of described substrate 200 also have control circuit and interconnection structure (not shown), and the first electrode 207 is connected with control circuit by interconnection structure with the second electrode 208.
The thickness of described barrier film 203 is 0.1 ~ 10 micron.
Although the present invention discloses as above, the present invention is not defined in this.Any those skilled in the art, without departing from the spirit and scope of the present invention, all can make various changes or modifications, and therefore protection scope of the present invention should be as the criterion with claim limited range.
Claims (20)
1. a formation method for capacitance pressure transducer, is characterized in that, comprising:
Substrate is provided, in described substrate, forms etched hole;
Form the first sacrifice layer on the substrate, described first sacrifice layer comprises fills the full Part I of etched hole and the Part II of cover part substrate surface, and Part I is positioned at immediately below Part II;
Described first sacrifice layer and substrate form barrier film;
Portion septum is formed the second sacrifice layer, and described second sacrifice layer is positioned at above the Part II of the first sacrifice layer;
The both sides sidewall surfaces of described second sacrifice layer forms the first relative electrode and the second electrode, and described first electrode and the second electrode part are positioned at membrane surface;
Remove described second sacrifice layer, form the first cavity between the first electrode and the second electrode;
Planarization or etch the back side of described substrate, until expose the first sacrifice layer bottom etched hole;
Remove described first sacrifice layer, form the second cavity in the bottom of barrier film;
The back side of substrate is formed the sealant of the bottom opening of described second cavity of sealing.
2. the formation method of capacitance pressure transducer, as claimed in claim 1, it is characterized in that, described second sacrifice layer width is less than the width of the Part II of the first sacrifice layer, and the length of the second sacrifice layer is equal to or less than the length of the first sacrifice layer Part II.
3. the formation method of capacitance pressure transducer, as claimed in claim 1, it is characterized in that, the thickness of the Part II of described first sacrifice layer is 0.1 ~ 10 micron, and the width of the Part II of the first sacrifice layer is 0.1 ~ 10000 micron.
4. the formation method of capacitance pressure transducer, as claimed in claim 1, it is characterized in that, the forming process of described first electrode and the second electrode is: form electrode material layer at the sidewall of described second sacrifice layer and the surface of surface and barrier film; Described electrode material layer forms mask layer, and described mask layer to cover on the second sacrifice layer both sides sidewall and electrode material layer on portion septum; Remove not by the electrode material layer that mask layer covers, the both sides sidewall surfaces of described second sacrifice layer forms the first relative electrode and the second electrode.
5. the formation method of capacitance pressure transducer, as claimed in claim 1, it is characterized in that, described first electrode or the second electrode comprise Part I and Part II, Part I is positioned at the both sides sidewall surfaces of the second sacrifice layer, and Part II is positioned at the surface of the barrier film on the top of the Part II of the first sacrifice layer and sidewall.
6. the formation method of capacitance pressure transducer, as claimed in claim 1, it is characterized in that, described first electrode or the second electrode comprise Part I and Part II, Part I is positioned at the both sides sidewall surfaces of the second sacrifice layer, and Part II is positioned at the surface of barrier film on the top of the Part II of the first sacrifice layer and sidewall and the suprabasil membrane surface of the second sacrifice layer both sides.
7. the formation method of capacitance pressure transducer, as claimed in claim 1, it is characterized in that, the spacing between the first electrode and the second electrode is 0.1 ~ 10000 micron.
8. the formation method of capacitance pressure transducer, as claimed in claim 1, it is characterized in that, the width of described etched hole is less than the width of the first sacrifice layer Part II, and the degree of depth of described etched hole is for being greater than 50 microns, and width is 0.1 ~ 10000 micron.
9. the formation method of capacitance pressure transducer, as claimed in claim 1, it is characterized in that, described first sacrifice layer or the second sacrificial layer material have high etching selection ratio relative to substrate, barrier film, the first electrode and the second electrode material.
10. the formation method of capacitance pressure transducer, as claimed in claim 9, it is characterized in that, the material of described first sacrifice layer or the second sacrifice layer is bottom antireflective coating, polysilicon, amorphous silicon, agraphitic carbon, SiN, SiON, SiCN, SiC, BN, SiCOH, BN or SiGe.
The formation method of 11. capacitance pressure transducer,s as claimed in claim 1, it is characterized in that, also comprise: formation control circuit and interconnection structure on other regions or other substrates of described substrate, the first electrode is connected with control circuit by interconnection structure with the second electrode.
The formation method of 12. capacitance pressure transducer,s as claimed in claim 1, is characterized in that, the thickness of described barrier film is 0.1 ~ 10 micron.
13. 1 kinds of capacitance pressure transducer,s, is characterized in that, comprising:
Substrate, is arranged in substrate and runs through the etched hole of its thickness;
Cover the barrier film of described substrate and etched hole, and the portion septum above etched hole raises up, have the 3rd cavity between the barrier film raised up and substrate, the 3rd cavity and etched hole form the second cavity;
Be positioned at the first relative electrode and the second electrode on protruding barrier film two ends, there is between the first electrode and the second electrode the first cavity;
Be positioned at the sealant on the back side of substrate, sealant seals the opening of the second cavity lower end.
14. capacitance pressure transducer,s as claimed in claim 13, is characterized in that, the height of described 3rd cavity is 0.1 ~ 10 micron, and width is 0.1 ~ 10000 micron.
15. capacitance pressure transducer,s as claimed in claim 13, it is characterized in that, the spacing between the first electrode and the second electrode is 0.1 ~ 10000 micron.
16. capacitance pressure transducer,s as claimed in claim 13, is characterized in that, the width of described 3rd cavity is greater than the width of etched hole.
17. capacitance pressure transducer,s as claimed in claim 13, it is characterized in that, described first electrode or the second electrode comprise Part I and Part II, and Part I is positioned at the both sides of the first cavity, and Part II is positioned at top and the sidewall surfaces of the bossing of barrier film.
18. capacitance pressure transducer,s as claimed in claim 13, it is characterized in that, described first electrode or the second electrode comprise Part I and Part II, Part I is positioned at the both sides of the first cavity, and Part II is positioned in the substrate of the top of the bossing of barrier film and the bossing both sides of sidewall surfaces and barrier film.
19. capacitance pressure transducer,s as claimed in claim 13, it is characterized in that, other regions of described substrate or the second substrate also have control circuit and interconnection structure, and the first electrode is connected with control circuit by interconnection structure with the second electrode.
20. capacitance pressure transducer,s as claimed in claim 13, is characterized in that, the thickness of described barrier film is 0.1 ~ 10 micron.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111170264A (en) * | 2018-11-12 | 2020-05-19 | 中国科学院微电子研究所 | Semiconductor device and method for manufacturing the same |
| CN115655534A (en) * | 2022-10-31 | 2023-01-31 | 歌尔微电子股份有限公司 | Pressure sensor and method for manufacturing pressure sensor |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2004147152A (en) * | 2002-10-25 | 2004-05-20 | Sanyo Electric Co Ltd | Acoustic sensor and method of manufacturing the same |
| DE102004061796A1 (en) * | 2004-12-22 | 2006-07-13 | Robert Bosch Gmbh | Micromechanical capacitive sensor element |
| EP2520917A1 (en) * | 2011-05-04 | 2012-11-07 | Nxp B.V. | MEMS Capacitive Pressure Sensor, Operating Method and Manufacturing Method |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111170264A (en) * | 2018-11-12 | 2020-05-19 | 中国科学院微电子研究所 | Semiconductor device and method for manufacturing the same |
| CN115655534A (en) * | 2022-10-31 | 2023-01-31 | 歌尔微电子股份有限公司 | Pressure sensor and method for manufacturing pressure sensor |
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