CN101324473A - Piezoresistance sensor chip and machining process thereof - Google Patents
Piezoresistance sensor chip and machining process thereof Download PDFInfo
- Publication number
- CN101324473A CN101324473A CNA2008101175224A CN200810117522A CN101324473A CN 101324473 A CN101324473 A CN 101324473A CN A2008101175224 A CNA2008101175224 A CN A2008101175224A CN 200810117522 A CN200810117522 A CN 200810117522A CN 101324473 A CN101324473 A CN 101324473A
- Authority
- CN
- China
- Prior art keywords
- micro
- cantilever
- sensor chip
- piezoresistance sensor
- pressure drag
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Abstract
The invention relates to a piezoresistive sensor chip and the processing technology thereof. The piezoresistive sensor chip is characterized in that the chip comprises a plurality of micro-cantilever beams and a signal detection circuit, wherein the fixed end of each micro-cantilever beam adopts a one-branched structure or a two-branched structure; a pressure resistor is arranged on a two-branched structure; the signal detection circuit is connected with each micro-cantilever beam by adopting an electrical bridge. By utilizing the piezoresistive sensor chip, a plurality of micro-cantilever beam structures and the signal detection circuit matched with the micro-cantilever beam structures are integrated, thereby enhancing the stability and the reliability of the chip. At the same time, through using the micro-cantilever beam structures with the branched fixed ends, the stress with different symbols can be prevented from appearing on the same pressure resistor; not only the contradiction between the transversal micro-force detection sensitivity and the width of the micro-cantilever beams is effectively solved, but also the single electrical bridge measurement and the double electrical bridge measurement can be realized. The piezoresistive sensor chip is manufactured by adopting the method of Post CMOS, and is suitable for batch production with low cost.
Description
Technical field
The present invention relates to a kind of microelectronic component and processing technology, particularly about a kind of piezoresistance sensor chip and processing technology thereof that is used for little horizontal applied force detection.
Background technology
(Micro Electro Mechanical Systems, MEMS) mechanics sensor is one of MEMS product the earliest to microelectromechanical systems, has pressure resistance type, condenser type, piezoelectric type etc. several by responsive principle classification.Wherein, use the piezoresistance sensor of based semiconductor micro cantilever structure to survey little power, have simple in structure, advantages such as cost is low, convenient signal treatment, have great application prospect in fields such as material science, precise measurement and control and biochemical reaction detections.
Basic functional principle based on the pressure resistance type mechanics sensor of micro cantilever structure is: when micro-cantilever bent under little power, the semiconductor lattice spacing can change, and made its resistivity change.There is certain relation in the size of the variation of resistance value and little power that applies on the micro-cantilever, and promptly resistance becomes greatly resistance decreasing during tension during pressurized.Just can obtain the changes in resistance situation by connecting signal processing circuit (as the Hui Sitong bridge circuit), thereby indirect calculation goes out the size of little power on the micro-cantilever.Micro-cantilever can along the structural plan laterally and vertical bending, detect the horizontal and vertical little power situation that comes from by the variation of resistance value.At present the structural design in the prior art and for improving the improvement that sensitivity is carried out is directed to mostly and detects vertical little power, is used to detect the making difficulty relatively of the micro-cantilever of horizontal little power.
Under horizontal oligodynamic action, half tension of neutral surface both sides of micro-cantilever, second half pressurized.If pressure drag is distributed in the both sides of neutral surface, then pressurized pressure drag value on one side will increase, and the pressure drag value on tension one side will reduce, thereby changes in resistance is little on the whole micro-cantilever, cause the sensitivity that detects very low.Prior art is that restrictively the controlled doping district makes the little power that does not occur opposite in sign in the same pressure drag zone in a certain side of neutral surface in the processing of pressure drag to this way to solve the problem.This method realizes easily for the situation of micro-cantilever broad, but needs micro-cantilever narrow as far as possible in order to obtain higher horizontal accuracy of detection.Because the restrictions such as horizontal expansion in the lithography alignment error, doping impurity process, add man-hour piezoresistive regions territory and cross over neutral surface probably, cause the deterioration of entire device performance.At present, people such as the B.W.Chui of Stanford Univ USA are in order to realize the detection of the little power in plane, the method of adopting inject is processed pressure drag on the vertical sidewall of micro-cantilever, but this method has been introduced some unconventional procedure of processings, and needs special equipment and make processing cost very high.The people such as T.Chu Duc of Holland Delft Polytechnics have proposed a kind of piezoresistance type microcantilever beam sensor that can be used for detecting both direction power, but this scheme is not to design for detecting horizontal little power specially, and the width of unresolved micro-cantilever reduces the problem that accuracy of detection improves.Simultaneously, the technical scheme that does not occur as yet at present sensor and signal processing circuit are integrated designs and job operation.For cost and the complexity that reduces technology, and can solve above problem, the present invention improves the limitation of prior art.
Summary of the invention
At the problems referred to above, the purpose of this invention is to provide a kind of horizontal little power that is used to detect, the micro-cantilever width reduces, and precision improves, and the piezoresistance sensor chip of integrated signal processing circuit and processing technology thereof.
For achieving the above object, the present invention takes following technical scheme: a kind of piezoresistance sensor chip is characterized in that: it comprises a plurality of micro-cantilevers and a signal deteching circuit; The stiff end of each micro-cantilever is a bifurcated structure, and pressure drag is arranged on the described bifurcated structure, and described signal deteching circuit adopts electric bridge to be connected with each described micro-cantilever.
Stick for one in described bifurcated structure and be provided with described pressure drag.
The quantity of described micro-cantilever is four, and itself and described signal deteching circuit adopt single bridging to connect.
Stick two of described bifurcated structure and to be respectively arranged with described pressure drag, the pressure drag that difference is stuck is UNICOM not mutually.
The quantity of described micro-cantilever is two, and it adopts doube bridge to be connected with described signal deteching circuit.
The processing technology of above-mentioned piezoresistance sensor chip, it may further comprise the steps: a) adopt P type silicon substrate, by standard complementary metal oxide semiconductor (CMOS) production line processing signal treatment circuit; Process the N trap simultaneously, and carry out the injection doping of pressure drag at desired location; B) use the plasma reinforced chemical vapour deposition method to form silicon oxide film in P type surface of silicon; C) in microelectromechanical systems is handled, on the silicon oxide film above the described N trap, make the structure graph of each micro-cantilever by lithography, use the method for reactive ion etching to remove the silicon oxide film on surface, relevant position; D) adopt the inductively coupled plasma technology that the place of having removed silicon oxide film in the described step c) is etched groove; E) use described plasma reinforced chemical vapour deposition method in the groove of step d), to form silicon oxide film; F) method of the described reactive ion etching of use is removed the silicon oxide film of channel bottom; G) use described inductively coupled plasma technology etching P type silicon substrate, realize that the structure of each micro-cantilever discharges; H) sliver is some single piezoresistance sensor chips.
Doped region in the described step a) is equal to or greater than setting range.
The degree of depth of groove exceeds the N trap in the described step d).
The present invention is owing to take above technical scheme, and it has the following advantages: 1, the present invention integrates a plurality of micro cantilever structures and the signal deteching circuit supporting with it, thereby has improved the stability and the reliability of chip.2, the present invention is by using the micro cantilever structure of stiff end bifurcated, avoided on same pressure drag, occurring the stress of distinct symbols, not only efficiently solve the contradiction between horizontal little power detection sensitivity and the micro-cantilever width, also can realize the measurement of single bridge measurement or double bridge.3, the pressure drag of micro cantilever structure of the present invention can be self-aligned to the design attitude on the bifurcated micro-cantilever in manufacturing process, thereby has eliminated the influence of factor such as horizontal expansion when mixing.4, the doping process of pressure drag of the present invention is finished in CMOS processing, finishes in the MEMS processing that is defined in the back of pressure drag shape, does not need any additional step in the whole process, has reduced the complexity of whole technology.5, the present invention adopts the method manufacturing of Post CMOS, is suitable for low-cost batch process the in batches.
Description of drawings
Fig. 1 be the present invention integrated the synoptic diagram of micro cantilever structure and signal deteching circuit
Fig. 2 is the schematic side view of bifurcated micro-cantilever of the present invention
Fig. 3 is the schematic top plan view of bifurcated micro-cantilever of the present invention
Fig. 4 a-4f is the processing process synoptic diagram of pressure drag sensing chip of the present invention
Fig. 5 is a pressure drag doped region synoptic diagram on the micro-cantilever of the present invention
Embodiment
Below in conjunction with accompanying drawing and example the present invention is described in detail.
As shown in Figure 1, the present invention is the some piezoresistance sensor chips of processing on a P type silicon substrate 1, and each piezoresistance sensor chip comprises a plurality of micro-cantilevers 2 and the signal deteching circuit 3 supporting with it.Chip manufacturing is finished, and forms some single piezoresistance sensor chips through sliver.
As Fig. 2, shown in Figure 3, the micro-cantilever 2 in each single piezoresistance sensor chip of the present invention, its stiff end 21 is a bifurcated structure, the cantilever end 22 of micro-cantilever 2 bears external force.Stick at 2 two branches of micro-cantilever and to be respectively arranged with pressure drag 23 that a pressure drag stuck in 23, two minutes UNICOM not mutually.Because resistance became big when pressure drag 23 had pressurized, the characteristic that resistance diminishes in the time of tension, therefore when cantilever end 22 was subjected to horizontal little power F, the pressure drag change in resistance trend that different branches are stuck on the stiff end 21 were opposite, and the variation of two pressure drags, 23 resistances has embodied the stressing conditions on the micro-cantilever.
Be positioned at that pressure drag on the micro-cantilever 2 can be formed single electric bridge or double bridge is measured.Because the structure of each micro-cantilever is identical and adopt same sampling technology, machine simultaneously, so the performance of pressure drag is in full accord above them.If two bifurcateds on each micro-cantilever 2 all are processed with pressure drag, when carrying out the doube bridge measurement, per two micro-cantilevers 2 are one group so, and four pressure drags 23 above them are formed Wheatstone bridges.If only stick processing pressure drag 23 at a branch of each micro-cantilever 2, then carrying out single bridge when measuring, four micro-cantilevers 2 are one group, four pressure drags 23 above them are formed Wheatstone bridges.The effect that two kinds of group bridge modes all have only a micro-cantilever 2 to be subjected to power when the measuring deformation that bends, the effect that does not stress on all the other micro-cantilevers 2.Pressure drag on the micro-cantilever 2 that does not stress is as reference resistance.Single electric bridge group bridge mode can reduce the complexity of metal connecting line and mutual interference mutually; But double bridge is measured compensation temperature and the influence of other factors to measuring.The width of piezoresistive regions length of field, bifurcated structure and the junction depth of doping process have determined the size of pressure drag value.This bifurcated structural design and job operation can effectively reduce the width k of micro-cantilever 2 simultaneously, thereby increase the sensitivity that detects.The wiring of pressure drag 23 and electric bridge is integrated machining on P type silicon substrate 1, can directly read electric signal thus, is used for the size that indirect calculation goes out cantilever end 22 suffered horizontal little power F of micro-cantilever 2.
The bifurcated structure Design of stiff end 21 is according to following principle: the little power F of maximum transversal that 1) can bear on the micro-cantilever 2 should in use not be damaged to guarantee it less than the permissible stress of its material; 2) as far as possible pressure drag 23 is arranged in the bigger zone of little power of bearing on the micro-cantilever 2, such as root, with the sensitivity that guarantees to detect near stiff end 21; 3) power with horizontal little power F different directions should not appear on the micro-cantilever 2; 4) the width k of micro-cantilever 2 is as far as possible little, to obtain higher horizontal little power F accuracy of detection.
Shown in Fig. 4 a～f, processing technology of the present invention is employing standard complementary metal oxide semiconductor (CMOS) (Complementary Metal-Oxide Semiconductor, CMOS) technology is in conjunction with microelectromechanical systems (Micro Electro Mechanical Systems, MEMS) processes piezoresistance sensor chip.The characteristics of this technology are: it integrates micro-cantilever 2 and signal deteching circuit 3, in the CMOS of standard production line processing signal testing circuit 3, on P type silicon substrate 1, process the processing of extra N trap 4, and finish the doping process of pressure drag 23 as micro-cantilever 2.The definition of the bifurcated structure width v of the width k of micro-cantilever and stiff end 21, after MEMS technology in finish.This job operation based on CMOS technology is called back CMOS (Post CMOS) method, is suitable for low-cost batch process the in batches.
The procedure of processing of piezoresistance sensor chip of the present invention is as follows:
1, shown in Fig. 4 a, adopt the standard P type silicon substrate 1 in the CMOS technology, process signal processing circuit 3 at the standard CMOS production line, and the metal lead wire 5 of micro cantilever structure 2.Process extra N trap 4 simultaneously, and finish the injection that in N trap 4 assigned address carries out P type pressure drag 23 and mix, doped region 6 (shown in Figure 5) can equal or exceed the setting range of pressure drag 23.
2, use plasma enhanced chemical vapor deposition (PECVD) method to form silicon oxide film 7, as the isolation and the protection of circuit on P type silicon substrate 1 surface.
3, shown in Fig. 4 b, on the assigned address of the silicon oxide film above the N trap 4, make the structure graph (as shown in Figure 3) of micro-cantilever by lithography, the bifurcated structure width v of definition micro-cantilever width k and stiff end 21 uses reactive ion etching (RIE) to remove a (as shown in Figure 3) between two bifurcateds and locates the silicon oxide film that b (shown in Fig. 4 b) outside the outline with micro-cantilever locates the surface.
4, shown in Fig. 4 c, the place of adopting inductively coupled plasma (ICP) technology that silicon oxide film has been removed at a place in the step 3 and b place etches groove, and gash depth will be above the degree of depth of N trap 4, and gash depth also is the micro-cantilever depth of beam.
5, shown in Fig. 4 d, use the PECVD method in the two place's grooves that process of step 4, to form silicon oxide film 8, realize side wall protection.
6, shown in Fig. 4 e, utilize the RIE technology that monox is carried out anisotropic etching, remove the silicon oxide film of two channel bottoms, and keep the silicon oxide film on the sidewall.
7, shown in Fig. 4 f, utilize the ICP technology in the step 4 that the P type silicon substrate 1 of two channel bottoms is carried out anisotropy and isotropic etching, realize that the structure of micro-cantilever discharges.Wherein stiff end 21 links to each other with P type silicon substrate 1, its upper bifurcation and stick whenever and to be provided with pressure drag 23; And cantilever end 22 is unsettled, is subjected to the effect of horizontal little power F.
As shown in Figure 5, by above technology, can obtain the piezoresistance sensor chip of an integrated signal deteching circuit 3.In step 1 and step 2, because pressure drag 23 is to spread earlier, back etching is shaped, so the factors such as transverse dispersion of the size of pressure drag 23 when mixing has nothing to do.Be convenient to accurately grasp the size of pressure drag 23 like this, make its automatic design attitude of aiming on the micro-cantilever 2.
Piezoresistance sensor chip of the present invention is mainly used in the horizontal little power that detects, and connects the detection that also can be used for vertical little power by electric bridge suitable in the chip.The present invention has solved the prior art processes complexity substantially, and the problem of transverse force accuracy of detection difference is fit to low-cost production in enormous quantities the in enormous quantities.
Claims (9)
1, a kind of piezoresistance sensor chip is characterized in that: it comprises a plurality of micro-cantilevers and a signal deteching circuit; The stiff end of each micro-cantilever is a bifurcated structure, and pressure drag is arranged on the described bifurcated structure, and described signal deteching circuit adopts electric bridge to be connected with each described micro-cantilever.
2, a kind of piezoresistance sensor chip as claimed in claim 1 is characterized in that: stick for one in described bifurcated structure and be provided with described pressure drag.
3, a kind of piezoresistance sensor chip as claimed in claim 2 is characterized in that: the quantity of described micro-cantilever is four, and itself and described signal deteching circuit adopt single bridging to connect.
4, a kind of piezoresistance sensor chip as claimed in claim 1 is characterized in that: stick two of described bifurcated structure and be respectively arranged with described pressure drag, the pressure drag that difference is stuck is UNICOM not mutually.
5, a kind of piezoresistance sensor chip as claimed in claim 4 is characterized in that: the quantity of described micro-cantilever is two, and it adopts doube bridge to be connected with described signal deteching circuit.
6, as the processing technology of the described a kind of piezoresistance sensor chip of claim 1～5, it may further comprise the steps:
A) adopt P type silicon substrate, process some signal processing circuits by standard complementary metal oxide semiconductor (CMOS) production line; Process some N traps simultaneously, and carry out the injection doping of pressure drag at desired location;
B) use the plasma reinforced chemical vapour deposition method to form silicon oxide film in P type surface of silicon;
C) in microelectromechanical systems is handled, on the silicon oxide film above the described N trap, make the structure graph of each micro-cantilever by lithography, use the method for reactive ion etching to remove the silicon oxide film on surface, relevant position;
D) adopt the inductively coupled plasma technology that the place of having removed silicon oxide film in the described step c) is etched groove;
E) use described plasma reinforced chemical vapour deposition method in the groove of step d), to form silicon oxide film;
F) method of the described reactive ion etching of use is removed the silicon oxide film of channel bottom;
G) use described inductively coupled plasma technology etching P type silicon substrate, realize that the structure of each micro-cantilever discharges;
H) sliver is some single piezoresistance sensor chips.
7, the processing technology of a kind of piezoresistance sensor chip as claimed in claim 6 is characterized in that: the doped region in the described step a) equals setting range.
8, the processing technology of a kind of piezoresistance sensor chip as claimed in claim 6 is characterized in that: the doped region in the described step a) is greater than setting range.
9, as the processing technology of claim 6 or 7 or 8 described a kind of piezoresistance sensor chips, it is characterized in that: the degree of depth of groove exceeds the N trap in the described step d).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2008101175224A CN101324473B (en) | 2008-07-31 | 2008-07-31 | Piezoresistance sensor chip and machining process thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2008101175224A CN101324473B (en) | 2008-07-31 | 2008-07-31 | Piezoresistance sensor chip and machining process thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101324473A true CN101324473A (en) | 2008-12-17 |
| CN101324473B CN101324473B (en) | 2010-07-21 |
Family
ID=40188101
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2008101175224A Expired - Fee Related CN101324473B (en) | 2008-07-31 | 2008-07-31 | Piezoresistance sensor chip and machining process thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101324473B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105974104A (en) * | 2016-05-12 | 2016-09-28 | 南京信息工程大学 | Giant piezoresistive structure based cantilever beam biochemical sensor and production method of cantilever beam |
-
2008
- 2008-07-31 CN CN2008101175224A patent/CN101324473B/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105974104A (en) * | 2016-05-12 | 2016-09-28 | 南京信息工程大学 | Giant piezoresistive structure based cantilever beam biochemical sensor and production method of cantilever beam |
| CN105974104B (en) * | 2016-05-12 | 2017-12-15 | 南京信息工程大学 | Cantilever beam biochemical sensor and cantilever beam preparation method based on huge piezo-resistive arrangement |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101324473B (en) | 2010-07-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| WO2017028466A1 (en) | Mems strain gauge chip and manufacturing process therefor | |
| CN100506686C (en) | Method for manufacturing piezoresistance type micro-cantilever beam sensor on SOI silicon sheet | |
| US6912759B2 (en) | Method of manufacturing a thin piezo resistive pressure sensor | |
| CN101627292B (en) | Pressure sensor | |
| CN107796955B (en) | Double-shaft acceleration sensor chip and preparation method thereof in more beam type single mass face | |
| US20040129087A1 (en) | Extraordinary piezoconductance in inhomogeneous semiconductors | |
| CN101419227A (en) | Piezoresistive micro-cantilever beam sensor based on suture stress concentration and manufacture method | |
| Kumar et al. | Effect of piezoresistor configuration on output characteristics of piezoresistive pressure sensor: an experimental study | |
| CN104729784A (en) | Beam and groove combined stepped island film micropressure sensor chip and manufacturing method thereof | |
| US5335544A (en) | Apparatus for measuring mechanical forces and force actions | |
| CN106092428A (en) | There is the pressure transducer devices of high sensitivity and pinpoint accuracy | |
| EP1511996A1 (en) | A cantilever sensor with a current shield and a method for its production | |
| CN113551812A (en) | Cross beam membrane stress concentration micro-pressure sensor chip and preparation method thereof | |
| KR101652369B1 (en) | Manufacturing method for piezoresistive pressure sensor using wet and dry etching process | |
| CN101324473B (en) | Piezoresistance sensor chip and machining process thereof | |
| CN114275731A (en) | MEMS-based double-beam type micro-pressure sensing core and preparation process thereof | |
| KR100904994B1 (en) | Method for fabricating pressure sensor and structure of the same | |
| Sujit et al. | Polysilicon piezoresistive MEMS pressure sensor: Study of analytical solutions for diaphragm and design & simulation | |
| Nambisan et al. | Sensitivity and non-linearity study and performance enhancement in bossed diaphragm piezoresistive pressure sensor | |
| CN105258738B (en) | A kind of pressure/two-dimensional magnetic field monolithic integrated sensor | |
| Stavrov et al. | MEMS sensors for mm-range displacement measurements with sub-nm resolution | |
| CN213023334U (en) | Polysilicon piezoresistive coefficient test structure | |
| Ham et al. | Design, fabrication, and characterization of piezoresisitve strain gage-based pressure sensors for mechatronic systems | |
| CN110207864B (en) | Sensitive membrane and force transmission guide rod integrated micro-force sensor and processing method thereof | |
| CN112284606B (en) | T-shaped cross beam cross island membrane pressure sensor chip and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20100721 Termination date: 20130731 |