阅读说明：本技术 陀螺仪及工艺修正陀螺仪正交误差的方法 (The method of gyroscope and process corrections gyroscope quadrature error ) 是由 邹波 郭梅寒 于 2019-09-03 设计创作，主要内容包括：本发明提供了一种陀螺仪及工艺修正陀螺仪正交误差的方法,所述方法包括：质量块在若干弹性梁配合下适于沿驱动方向和检测方向活动；所述若干弹性梁包括相配合的第一弹性梁和第二弹性梁,所述第一弹性梁与所述第二弹性梁具有不同的结构,从而在限定所述若干弹性梁的工艺中,工艺参数的调整对于所述第一弹性梁的刚度和所述第二弹性梁的刚度的影响程度不同,从而可以通过对所述第一弹性梁的刚度和所述第二弹性梁的刚度的调整来抵消所述陀螺仪的正交误差。(The present invention provides a kind of gyroscope and the methods of process corrections gyroscope quadrature error, which comprises mass block is suitable under the cooperation of several spring beams along driving direction and detection direction activity；Several spring beams include the first spring beam and the second spring beam matched, first spring beam has different structures from second spring beam, to in the technique for limiting several spring beams, the adjustment of technological parameter is different for the rigidity of first spring beam and the influence degree of the rigidity of second spring beam, so as to offset the quadrature error of the gyroscope by the adjustment of the rigidity of rigidity and second spring beam to first spring beam.)

1. a kind of method for correcting gyroscope quadrature error, which is characterized in that mass block is suitable for edge under the cooperation of several spring beams Driving direction and detection direction activity；Several spring beams include the first spring beam and the second spring beam matched, described First spring beam has different structures from second spring beam, thus in the technique for limiting several spring beams, work The adjustment of skill parameter is different for the rigidity of first spring beam and the influence degree of the rigidity of second spring beam, thus The gyroscope can be offset by the adjustment of the rigidity of rigidity and second spring beam to first spring beam Quadrature error.

2. the method as described in claim 1, which is characterized in that the technique for limiting several spring beams is photoetching work Skill, the size of first spring beam and second spring beam is adjusted by the photoetching process, to influence the rigid of the two Degree.

3. method according to claim 2, which is characterized in that adjusted in the photoetching process by exposure energy described The size of first spring beam and second spring beam.

4. the method as described in claim 1, which is characterized in that first spring beam is single-spar construction, second elasticity Beam includes several elastic beams, and the size of any elastic beam is less than the size of first spring beam, second bullet The size of property beam is limited by the size of several elastic beams.

5. method as claimed in claim 4, which is characterized in that the quantity of the elastic beam is 2.

6. the method as described in claim 1, which is characterized in that on the wafer for preparing the gyroscope, such as different zones Gyroscope have different quadrature errors, then the different zones using accordingly the technological parameter come so that the difference The quadrature error of the gyroscope in region can be cancelled.

7. method as claimed in claim 5, which is characterized in that the technique for limiting several spring beams is photoetching work Skill uses corresponding exposure energy to the different zones by stepper, to adjust first spring beam The size of size and second spring beam, to influence the rigidity of the two.

8. the method as described in claim 1, which is characterized in that be provided with multiple first spring beams and one described Two spring beams.

9. the method as described in claim 1, which is characterized in that first spring beam and second spring beam are arranged at The periphery of the mass block.

10. a kind of gyroscope, which is characterized in that using the method preparation as described in claim 1~9 is any.

Technical field

The present invention relates to field of semiconductor manufacture more particularly to a kind of gyroscope and process corrections gyroscope quadrature errors Method.

Background technique

MEMS (Micro Electro Mechanical System, MEMS) device is since its is small in size, cost It low, the features such as integration is good, has been able to be more and more widely used in the products such as such as consumer electronics, medical treatment, automobile.Wherein, Capacitive MEMS gyroscope is much smaller than the gyroscope of other traditional technologies in cost, size, power consumption, extensive at present The fields such as the gesture stability for mobile phone photograph stabilization, unmanned plane, robot and vehicle.

Capacitive MEMS gyroscope is the device based on micromachined, relies primarily on coriolis force to detect angular speed letter Number, there are two operation modes, i.e. driven-mode and sensed-mode for tool.As shown in Figure 1, in the ideal case, when the drive of gyroscope After moved end applies driven-mode eigenfrequency electric signal, the mass block of gyroscope can again drive shaft (X-axis) done with eigenfrequency it is past Multiplex vibration.When the external world have Z axis to turning rate input when, under the action of coriolis force, mass block can simultaneously in detection axis (Y-axis) The size of vibration, Oscillation Amplitude and angular speed is in a linear relationship, by detecting mass block in the Oscillation Amplitude of detection axis Acquire current angular speed size.

There is non-ideal type structure, real work since the manufacturing process defect of micromachined may result in gyroscope When, not strictly in driving shaft vibration, actual direction of vibration may have one small mass block with drive shaft under driven-mode Angular deviation, this deviation can make the vibration of drive shaft be directly coupled to detection axis, even if so that gyroscope is in angular speed Input also still has detection signal output in the case where being zero, this phenomenon is referred to as quadrature error.

Compared to fibre optic gyroscope, the floated-type gyroscope for being traditionally used for the fields such as Aeronautics and Astronautics, military project, condenser type The absolute precision and bias stability of MEMS gyroscope still have obvious gap.The quadrature error of capacitive MEMS gyroscope is to make At a principal element of this gap, numerous documents are to the existing research extensively and profoundly of quadrature error in the industry, when gyroscope is set When using difference output on meter, ideally quadrature error can be by perfect positive and negative counteracting.But it is processed in MEMS wafer Cheng Zhong, current techniques working ability not can guarantee the crucial knots such as the spring beam rigidity of positive and negative electrode capacitance spacing or influence capacitive displacement Structure is full symmetric, and quadrature error no doubt exists.Additional mechanism is needed to reduce quadrature error, or reduces quadrature error to detection The influence of signal.

The mode of most common compensation quadrature error signal is to measure and work as in gyroscope chip test phase in the industry When quadrature error value, then try to cut the signal of quadrature error part in the signal processing circuit, to reduce orthogonal mistake Influence of the difference to gyroscope detection output signal.The shortcomings that this method is only to be compensated from signal, gyroscope structure sheet The practical quadrature error movement of body still has, and when compensation circuit itself fluctuates, after offset variation, still suffers from quadrature error Signal generates.Also there is the method for other physics amendment gyroscope structure quadrature errors, as laser repairs resistance, but its operation difficulty and cost It is higher.

Summary of the invention

In view of the problems of the prior art, the present invention provides a kind of method for correcting gyroscope quadrature error, and mass block exists Several spring beam cooperations are lower to be suitable for along driving direction and detection direction activity；Several spring beams include the first bullet matched Property beam and the second spring beam, first spring beam has different structures from second spring beam, thus described in the restriction In the technique of several spring beams, the adjustment of technological parameter for first spring beam rigidity and second spring beam it is rigid The influence degree of degree is different, so as to pass through the tune of the rigidity of rigidity and second spring beam to first spring beam The whole quadrature error to offset the gyroscope.

Further, the technique for limiting several spring beams is photoetching process, is adjusted by the photoetching process The size of first spring beam and second spring beam, to influence the rigidity of the two.

Further, first spring beam and second bullet are adjusted by exposure energy in the photoetching process The size of property beam.

Further, first spring beam is single-spar construction, and second spring beam includes several elastic beams, any The size of the elastic beam is less than the size of first spring beam, and the size of second spring beam is by several bullets The size of property beam is limited.

Further, the quantity of the elastic beam is 2.

Further, on the wafer for preparing the gyroscope, as the gyroscope of different zones has different orthogonal mistakes Difference, then the different zones using the corresponding technological parameter come so that the gyroscope of the different zones quadrature error It can be cancelled.

Further, the technique for limiting several spring beams is photoetching process, by stepper come pair The different zones use corresponding exposure energy, to adjust the size of first spring beam and the ruler of second spring beam It is very little, to influence the rigidity of the two.

Further, multiple first spring beams and second spring beam are provided with.

Further, first spring beam and second spring beam are arranged at the periphery of the mass block.

The present invention also provides a kind of gyroscopes, are prepared using the method for above-mentioned amendment gyroscope quadrature error.

The present invention also provides a kind of patterns to shift version, at least pattern for the spring beam of quality of connection block in gyroscope Change, the pattern of the spring beam includes the first spring beam pattern and the second spring beam pattern, the first spring beam pattern and institute It is different to state the second spring beam pattern, so that the variation of exposure energy is to described in the photoetching process for patterning the spring beam The size of first spring beam is different with the influence degree of the size of second spring beam.

Further, the first spring beam pattern is single line item, and the second spring beam pattern includes several sub-line items, The size of any sub-line item is less than the size of the first spring beam pattern, and the size of the second spring beam pattern is by institute The size for stating several sub-line items is limited.

The method of gyroscope and process corrections gyroscope quadrature error of the invention, passes through the improvement knot to elastic beam structure The adjustment for closing technological parameter to effectively cancel out quadrature error, and can solve wafer to overcome the asymmetry of spring beam rigidity The problem of upper quadrature error is unevenly distributed.In practical applications, compared to the side of other physics amendment gyroscope structure quadrature error Method is easily achieved and at low cost if laser repairs resistance.

It is described further below with reference to technical effect of the attached drawing to design of the invention, specific structure and generation, with It is fully understood from the purpose of the present invention, feature and effect.

Detailed description of the invention

Fig. 1 is a kind of orthogonal coupling schematic diagram of existing capacitive MEMS gyroscope；

Fig. 2 is the structural schematic diagram of a specific embodiment of the invention；

Fig. 3 is quadrature error distribution schematic diagram in one embodiment of the present of invention；

Fig. 4 is to increase the structural schematic diagram after exposure energy in one embodiment of the present of invention；

Fig. 5 is that the structural schematic diagram after exposure energy is reduced in one embodiment of the present of invention.

Specific embodiment

In the description of embodiments of the present invention, it is to be understood that term " on ", "lower", "front", "rear", " left side ", The orientation of the instructions such as " right side ", " vertical ", "horizontal", "top", "bottom", "inner", "outside", " clockwise ", " counterclockwise " or position are closed System is merely for convenience of description of the present invention and simplification of the description to be based on the orientation or positional relationship shown in the drawings, rather than indicates Or imply that signified device or element must have a particular orientation, be constructed and operated in a specific orientation, therefore cannot understand For the limitation to invention.Attached drawing is schematic diagram or concept map, relationship and each section between each section thickness and width it Between proportionate relationship etc., it is not completely the same with its actual value.

Fig. 2 is the structural schematic diagram of a specific embodiment of the invention, including center anchor point A0, mass block M0, Fixed anchor point A1~A4 and fixed electrode E1~E4, overall structure are axisymmetricly arranged both horizontally and vertically.

By spring beam La, Lb, Lc, Ld and mass block M0 connection, spring beam La, Lb, Lc, Ld connect center anchor point A0 respectively It connects on four angles of mass block M0 and extends outwardly in 45 degree and same length and be connected to mass block M0, make spring beam La and Ld It is arranged symmetrically in the horizontal direction, spring beam La and Lb are vertically arranged symmetrically, and spring beam Lb and Lc is symmetrical in the horizontal direction Arrangement, spring beam Lc and Ld are vertically arranged symmetrically.

Fixed electrode E1 and E3 are symmetrically disposed in the left and right sides of mass block M0, are respectively set on fixed electrode E1 and E3 Have and be directed toward the horizontal-extending fixed broach E10 and E30 in the direction mass block M0, is respectively arranged with level at left and right sides of mass block M0 Extend movable comb E11 and E31 that ground is matched with fixed broach E10 and E30.Fixed electrode E1 and E3 can be used as gyroscope Driving electrodes or detecting electrode, in the present embodiment, using fixed electrode E1 and E3 as driving electrodes.

Fixed electrode E2 and E4 are symmetrically disposed in the two sides up and down of mass block M0, are respectively set on fixed electrode E2 and E4 Have and be directed toward the vertically extending fixed broach E20 and E40 in the direction mass block M0, the two sides up and down of mass block M0 are respectively arranged with vertically Extend movable comb E21 and E41 that ground is matched with fixed broach E20 and E40.Fixed electrode E2 and E4 can be used as gyroscope Driving electrodes or detecting electrode, in the present embodiment, using fixed electrode E2 and E4 as detecting electrode.

Fixed anchor point A1~A4 is symmetrically dispersed in four angles end of the periphery mass block M0, and fixed anchor point A1~A4 leads to respectively Spring beam L1~L4 is crossed to be connected with mass block M0.Spring beam L1~L4 all has L-type structure, the L-type structure of the present embodiment The equal length of horizontal segment and vertical section.In further embodiments, spring beam L1~L4 can also be suitable for matching using other Mass block M0 is closed in driving and the movable structure of detection direction, such as arcuate structure.

Spring beam L1, L3, L4 structure is identical, and spring beam L2 is similar to spring beam L1, L3, L4 overall structure, and difference is, Spring beam L1, L3, L4 are all made of single girder construction, and spring beam L2 is made of two thinner spring beam L21 and L22 , spring beam L21 and L22 all have L-type structure, and the two is integrally set in distance, and the spring beam L22 in the present embodiment is in L-type There is a bit of extension in 90 degree of knees of structure in the horizontal direction and the vertical direction, and extended segment is connected with spring beam L21, So that spring beam L2 is integrally consolidated.

Spring beam L2 is designed to its rigidity on driving direction and detection direction and matches with spring beam L1, L3, L4, I.e. the structure of the present embodiment will not generate quadrature error in the ideal situation.

But as previously mentioned, the issuable defect of manufacturing process institute of micromachined will lead to product and non-ideal type occurs Structure, for capacitive MEMS gyroscope, it is possible to create the reason of quadrature error is numerous, including but not limited to processing technology The factors such as capacitor spacing, spring beam rigidity, stress distribution asymmetry caused by imperfect, and often many factors in actual product It mixes, or even also different with the quadrature error of different zones chip on wafer, it is consistent to gyroscope properties of product Property and yield significantly affect.

Such structure asymmetry as caused by fabrication error usually with processing step used in concrete technology flow process, equipment And its parameter setting is closely related.For the wafer of volume production, processing step and device parameter are usually not likely to change, many feelings It is difficult to avoid the non-uniform Distribution of product parameters on wafer adjusting process and/or parameter under condition, this is because many works It is heteropical in skill to occur being constrained to capacity of equipment, so keeping the stability of technique and equipment for production It is only most important.Therefore usually there is similar quadrature error gradient distribution on the more wafers of volume production.

It is based in existing production, the repeatability that quadrature error is distributed on wafer allows to using the present embodiment Structure relatively conveniently corrects quadrature error according to different zones on wafer respectively.

Firstly, by the distribution of the quadrature error value of chip on gyroscope wafer on test confirmation production line, below with Fig. 3 Shown in be distributed for, it is maximum it is round indicate wafer, wherein 4 × 4 16 grids are exposure of the stepper on wafer Light sequential matrix, wafer 4 region ZONE1~ZONE4 gyro chip there are biggish quadrature error, wherein region ZONE1 and region ZONE3 error amount are positive, and region ZONE2 and region ZONE4 error amount are negative.Correspond to the top of the present embodiment In spiral shell instrument structure, using fixed electrode E1 and E3 as driving electrodes, fixed electrode E2 and E4 are as detecting electrode, thus when elasticity When beam L2 rigidity is greater than spring beam L1, L3, L4, asymmetric resilient support will lead to additional positive quadrature error signal； When spring beam L2 rigidity is less than spring beam L1, L3, L4, the quadrature error of additional negative direction will lead to.

It when forming the photoengraving pattern of spring beam L1~L4, is exposed using stepper, in establishment photoetching work During making file, increases exposure energy when the 6th time and the 11st time exposure, make region ZONE1's and region ZONE3 The critical size of spring beam L1~L4 reduces in chip, i.e. the width of the photoetching lines of reduction spring beam L1~L4, makes subsequent quarter The width of the spring beam L1~L4 formed after etching technique is less than the width of the corresponding spring beam using default exposure energy.

As shown in figure 4, after increasing exposure energy (dotted line is the line width increased after exposure energy), for spring beam L1, The △ d that the influence of L3, L4 width is twice, i.e. the photoetching line thickness of spring beam L1, L3, L4 respectively reduce 2 × △ d；And it is right For spring beam L2, the photoetching line thickness of spring beam L21 and L22 therein is reduced 2 × △ d respectively, thus elastic Width reduces 4 × △ d to beam L2 on the whole, so that spring beam L2 reduces more than spring beam L1, L3, L4 in rigidity, from And the quadrature error of additional negative direction is generated, quadrature error caused by the error is imperfect with technique is contrary, can be mutual It offsets.

Similarly, exposure energy is reduced when the 7th time and the 10th time exposure, makes the core of region ZONE2 and region ZONE4 The critical size of spring beam L1~L4 reduces in piece, i.e. the width of the photoetching lines of increase spring beam L1~L4, makes subsequent etching The width of the spring beam L1~L4 formed after technique is greater than the width of the corresponding spring beam using default exposure energy.

As shown in figure 5, after reducing exposure energy (dotted line is the line width reduced after exposure energy), for spring beam L1, The △ d that the influence of L3, L4 width is twice, i.e. the photoetching line thickness of spring beam L1, L3, L4 increase 2 × △ d respectively；And it is right For spring beam L2, the photoetching line thickness of spring beam L21 and L22 therein all increases 2 × △ d respectively, thus elastic Width increases 4 × △ d to beam L2 on the whole, so that spring beam L2 increases more than spring beam L1, L3, L4 in rigidity, from And the quadrature error of additional positive direction is generated, quadrature error caused by the error is imperfect with technique is contrary, can be mutual It offsets.

Carrying out line width adjustment in actual production to spring beam by exposure energy in above-mentioned photoetching process is to be easy in fact Existing, this is because the feature sizes (micron order) of the spring beam in such product are much larger than the feature sizes of general IC circuit (nanoscale) can have very big surplus selection suitable so that the width of spring beam and the lithographic process window of spacing are very wide Technological parameter line width effectively adjusted.

In further embodiments, when being exposed energy adjusting, need to increase spring beam L2 relative to spring beam L1, Spring beam L2 can be designed as being made of a plurality of elastic beam thus, from the foregoing, it will be observed that elastic beam by the variation degree of L3, L4 Quantity it is more, variation degree is bigger.For any elastic beam of spring beam L2, size (being embodied in width) is less than Any size in spring beam L1, L3, L4.

The present embodiment further includes pattern transfer version (or perhaps reticle) being used in the above method, is at least used for The patterning of spring beam L1~L4.As previously mentioned, spring beam L2 is designed to its rigidity on driving direction and detection direction Match with spring beam L1, L3, L4, i.e., the structure of the present embodiment will not generate quadrature error in the ideal situation.For elasticity The design of beam L2, be based on theory can obtain corresponding domain, thus be made pattern transfer version, for actual production processing in, Due to some processing line overall variations, such as great equipment adjusts or carries out transferred product to different manufactories It processes (reticle can also shift together), generates the rigidity of the spring beam L2 of wafer on the whole relative to spring beam L1, L3, L4 Drift, but the modification method based on the present embodiment, the rigidity of spring beam L2 can adjust in a larger range, i.e., The rigidity of spring beam L2 is the rigidity that can be both adjusted to less than spring beam L1, L3, L4, can also be adjusted to be greater than elasticity The rigidity of beam L1, L3, L4, thus even if offset occurs in the integrated artistic of processing line, it still can be by adjusting photolithographic parameters Come so that spring beam L2 matches with spring beam L1, L3, L4, to form preset process condition.Similarly, when wafer be taken in it is orthogonal Error distribution is because of above situation when changing, still can modification method through the invention targetedly adjusted.

The preferred embodiment of the present invention has been described in detail above.It should be appreciated that those skilled in the art without It needs creative work according to the present invention can conceive and makes many modifications and variations.Therefore, all technologies in the art Personnel are available by logical analysis, reasoning, or a limited experiment on the basis of existing technology under this invention's idea Technical solution, all should be within the scope of protection determined by the claims.