Acceleration sensor and method of manufacturing the same

Abstract

The application discloses an acceleration sensor and a manufacturing method thereof. The acceleration sensor comprises a first capacitor, a second capacitor, a third capacitor and a fourth capacitor on a substrate. The first capacitor comprises a second detection mass and a first detection electrode. The second capacitor comprises a first detection mass and a first detection electrode. The third capacitor comprises a second detection mass and a second detection electrode. The fourth capacitor comprises a first detection mass and a second detection electrode. The first detection electrode and the second detection electrode are located between the first detection mass and the second detection mass and are independent of each other and located in the same plane. The application forms a full-bridge capacitor detection structure by the first detection mass, the second detection mass, the first detection electrode and the second detection electrode located between the first detection mass and the second detection mass, which can effectively reduce parasitic capacitance, optimize noise, improve stability and sensitivity.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and in particular to an accelerometer and its manufacturing method. Background Technology

[0002] An accelerometer is a sensor used to measure the acceleration of an object's motion or the acceleration due to gravity. It can detect the magnitude and direction of acceleration and convert these physical quantities into electrical signals.

[0003] MEMS accelerometers are widely used in consumer electronics, automotive electronics, and industrial electronics. With the rapid development of electronic technology, new application scenarios, such as smart wearables, automotive safety systems, and medical rehabilitation, place even higher demands on the stability and sensitivity of MEMS accelerometers.

[0004] Existing MEMS accelerometers, due to their planar layout design, have a large detection mass area, which introduces more parasitic capacitance, resulting in more noise and affecting the sensitivity of the MEMS accelerometer.

[0005] Conventional MEMS accelerometers are mostly planar designs, which have disadvantages such as large device size, large parasitic capacitance, and high noise. Summary of the Invention

[0006] In view of the above problems, the purpose of this application is to provide an accelerometer and its manufacturing method that effectively reduces parasitic capacitance, optimizes noise, and improves stability and sensitivity.

[0007] According to one aspect of this application, an acceleration sensor is provided, comprising:

[0008] The first capacitor, the second capacitor, the third capacitor, and the fourth capacitor are located on the substrate.

[0009] The first capacitor includes a second detection mass block and a first detection electrode.

[0010] The second capacitor includes a first detection mass block and a first detection electrode.

[0011] The third capacitor includes a second detection mass block and a second detection electrode.

[0012] The fourth capacitor includes a first detection mass block and a second detection electrode.

[0013] The first detection electrode and the second detection electrode are located between the first detection mass block and the second detection mass block, and the first detection electrode and the second detection electrode are independent of each other and located on the same plane.

[0014] Optionally, the second capacitor and the first capacitor are stacked along the first direction, and the fourth capacitor and the third capacitor are stacked along the first direction.

[0015] Optionally, the first capacitor and the third capacitor are arranged along the second direction, and the second capacitor and the fourth capacitor are arranged along the second direction, which is perpendicular to the first direction.

[0016] Optionally, it also includes:

[0017] A first insulating layer is located between the substrate and the first detection mass block, and a portion of the first insulating layer contacts the first detection mass block to support the first detection mass block.

[0018] Optionally, it also includes:

[0019] A wiring layer is located on the edge region of the first insulating layer, and the wiring layer and the first detection quality block have a first gap along the second direction; and

[0020] A second insulating layer is located on a portion of the wiring layer to create a second gap between the wiring layer and the first detection quality block along a first direction.

[0021] Optionally, it also includes:

[0022] A third insulating layer is located on a portion of the first detection mass block, and a portion of the third insulating layer is located between the first detection mass block and the first detection electrode, and between the first detection mass block and the second detection electrode, to create a third gap between the first detection mass block and the first detection electrode, and a fourth gap between the first detection mass block and the second detection electrode; and

[0023] A fourth insulating layer is located between a portion of the third insulating layer and a portion of the second detection mass block. The stacked fourth and third insulating layers separate the first and second detection mass blocks along a first direction and provide a fifth gap between the second detection mass block and the first detection electrode, and a sixth gap between the second detection mass block and the second detection electrode.

[0024] Optionally, the fourth insulating layer has a first distance from the first detection electrode along the second direction, and the fourth insulating layer has a second distance from the second detection electrode along the second direction, wherein the first distance and the second distance are equal.

[0025] Optionally, the upper plate region of the first capacitor in the second detection mass block, which is opposite to the first detection electrode, has a first vertical projection, and the lower plate region of the second capacitor in the first detection mass block, which is opposite to the first detection electrode, has a second vertical projection, wherein the areas of the first vertical projection and the second vertical projection are equal.

[0026] Optionally, the upper plate region of the third capacitor in the second detection mass block, which is opposite to the second detection electrode, has a third vertical projection, and the lower plate region of the fourth capacitor in the first detection mass block, which is opposite to the second detection electrode, has a fourth vertical projection, wherein the areas of the third vertical projection and the fourth vertical projection are equal.

[0027] Optionally, the upper plate region of the first capacitor in the second detection mass block, which is opposite to the first detection electrode, has a first vertical projection, and the upper plate region of the third capacitor in the second detection mass block, which is opposite to the second detection electrode, has a third vertical projection, the area of ​​which is equal to that of the first vertical projection.

[0028] Optionally, the lower plate region of the second capacitor in the first detection mass block, which is opposite to the first detection electrode, has a second vertical projection, and the lower plate region of the fourth capacitor in the first detection mass block, which is opposite to the second detection electrode, has a fourth vertical projection, wherein the areas of the second vertical projection and the fourth vertical projection are equal.

[0029] Optionally, the first detection mass block is provided with a first opening, which is close to the first detection electrode or close to the second detection electrode.

[0030] Optionally, the second detection mass block is provided with a second opening, which is close to the first detection electrode or close to the second detection electrode.

[0031] Optionally, the second opening corresponds to the first opening.

[0032] Optionally, the first detection mass block further includes a third opening, which divides the first detection mass block into a first region and a second region.

[0033] The first region includes at least the lower plate region of the second capacitor and the lower plate region of the fourth capacitor, and the first opening is located in the first region.

[0034] The second region is used to support the first detection electrode and the second detection electrode, and a third insulating layer is provided between the second region of the first detection mass block and the first detection electrode and the second detection electrode.

[0035] Optionally, the first detection mass block is parallel to the first detection electrode, the first detection mass block is parallel to the second detection electrode, the second detection mass block is parallel to the first detection electrode, and the second detection mass block is parallel to the second detection electrode.

[0036] Optionally, the first detection electrode and the second detection electrode are symmetrical about the central axis of the accelerometer.

[0037] Optionally, when the first detection mass block tilts toward the first detection electrode and simultaneously causes the second detection mass block to tilt toward the second detection electrode, the first capacitor and the fourth capacitor decrease, while the second capacitor and the third capacitor increase.

[0038] Optionally, when the first detection mass block tilts toward the second detection electrode and simultaneously causes the second detection mass block to tilt toward the first detection electrode, the first capacitor and the fourth capacitor increase, while the second capacitor and the third capacitor decrease.

[0039] According to another aspect of this application, a method for manufacturing an acceleration sensor is provided, comprising:

[0040] A first capacitor, a second capacitor, a third capacitor, and a fourth capacitor are formed on the substrate.

[0041] The first capacitor includes a second detection mass block and a first detection electrode.

[0042] The second capacitor includes a first detection mass block and a first detection electrode.

[0043] The third capacitor includes a second detection mass block and a second detection electrode.

[0044] The fourth capacitor includes a first detection mass block and a second detection electrode.

[0045] The first detection electrode and the second detection electrode are located between the first detection mass block and the second detection mass block, and the first detection electrode and the second detection electrode are independent of each other and located on the same plane.

[0046] Optionally, the second capacitor and the first capacitor are stacked along the first direction, and the fourth capacitor and the third capacitor are stacked along the first direction.

[0047] Optionally, the first capacitor and the third capacitor are arranged along the second direction, and the second capacitor and the fourth capacitor are arranged along the second direction, which is perpendicular to the first direction.

[0048] Optionally, it also includes:

[0049] A first insulating layer is formed between the substrate and the first detection mass block, and a portion of the first insulating layer contacts the first detection mass block to support the first detection mass block.

[0050] Optionally, it also includes:

[0051] A wiring layer is formed on the edge region of the first insulating layer, the wiring layer having a first gap with the first detection mass block along a second direction; and

[0052] A second insulating layer is formed on a portion of the wiring layer to create a second gap between the wiring layer and the first detection mass block along a first direction.

[0053] Optionally, it also includes:

[0054] A third insulating layer is formed on a portion of the first detection mass block, the portion of the third insulating layer being located between the first detection mass block and the first detection electrode, and between the first detection mass block and the second detection electrode, to create a third gap between the first detection mass block and the first detection electrode, and a fourth gap between the first detection mass block and the second detection electrode; and

[0055] A fourth insulating layer is formed between a portion of the third insulating layer and a portion of the second detection mass block. The stacked fourth insulating layer and the third insulating layer separate the first detection mass block and the second detection mass block along a first direction, and a fifth gap is formed between the second detection mass block and the first detection electrode, and a sixth gap is formed between the second detection mass block and the second detection electrode.

[0056] Optionally, the fourth insulating layer has a first distance from the first detection electrode along the second direction, and the fourth insulating layer has a second distance from the second detection electrode along the second direction, wherein the first distance and the second distance are equal.

[0057] Optionally, the upper plate region of the first capacitor in the second detection mass block, which is opposite to the first detection electrode, has a first vertical projection, and the lower plate region of the second capacitor in the first detection mass block, which is opposite to the first detection electrode, has a second vertical projection, wherein the areas of the first vertical projection and the second vertical projection are equal.

[0058] Optionally, the upper plate region of the third capacitor in the second detection mass block, which is opposite to the second detection electrode, has a third vertical projection, and the lower plate region of the fourth capacitor in the first detection mass block, which is opposite to the second detection electrode, has a fourth vertical projection, wherein the areas of the third vertical projection and the fourth vertical projection are equal.

[0059] Optionally, the upper plate region of the first capacitor in the second detection mass block, which is opposite to the first detection electrode, has a first vertical projection, and the upper plate region of the third capacitor in the second detection mass block, which is opposite to the second detection electrode, has a third vertical projection, the area of ​​which is equal to that of the first vertical projection.

[0060] Optionally, the lower plate region of the second capacitor in the first detection mass block, which is opposite to the first detection electrode, has a second vertical projection, and the lower plate region of the fourth capacitor in the first detection mass block, which is opposite to the second detection electrode, has a fourth vertical projection, wherein the areas of the second vertical projection and the fourth vertical projection are equal.

[0061] Optionally, it also includes:

[0062] A first opening is formed on the first detection mass block, the first opening being close to the first detection electrode or close to the second detection electrode.

[0063] Optionally, it also includes:

[0064] A second opening is formed on the second detection mass block, the second opening being close to the first detection electrode or close to the second detection electrode.

[0065] Optionally, the second opening corresponds to the first opening.

[0066] Optionally, it also includes:

[0067] A third opening is formed on the first detection mass block, the third opening dividing the first detection mass block into a first region and a second region.

[0068] The first region includes at least the lower plate region of the second capacitor and the lower plate region of the fourth capacitor, and the first opening is located in the first region.

[0069] The second region is used to support the first detection electrode and the second detection electrode, and a third insulating layer is provided between the second region of the first detection mass block and the first detection electrode and the second detection electrode.

[0070] Optionally, the first detection mass block is parallel to the first detection electrode, the first detection mass block is parallel to the second detection electrode, the second detection mass block is parallel to the first detection electrode, and the second detection mass block is parallel to the second detection electrode.

[0071] Optionally, the first detection electrode and the second detection electrode are symmetrical about the central axis of the accelerometer.

[0072] Optionally, when the first detection mass block tilts toward the first detection electrode and simultaneously causes the second detection mass block to tilt toward the second detection electrode, the first capacitor and the fourth capacitor decrease, while the second capacitor and the third capacitor increase.

[0073] Optionally, when the first detection mass block tilts toward the second detection electrode and simultaneously causes the second detection mass block to tilt toward the first detection electrode, the first capacitor and the fourth capacitor increase, while the second capacitor and the third capacitor decrease.

[0074] Optionally, forming a second insulating layer on a portion of the wiring layer includes:

[0075] A patterned first sacrificial insulating layer is grown on the surface of the wiring layer and a portion of the first insulating layer to leave a connection window for the first detection quality block;

[0076] Release the first sacrificial insulating layer located on the surface of the first insulating layer and a portion of the first sacrificial insulating layer located on the surface of the wiring layer to form a second insulating layer supporting the second region of the first detection mass block, a first gap between the wiring layer and the first detection mass block along the second direction, and a second gap between the wiring layer and the first detection mass block along the first direction.

[0077] Optionally, forming a third insulating layer includes:

[0078] A patterned second sacrificial insulating layer is grown on the surface of the first detection mass block;

[0079] A portion of the second sacrificial insulating layer located on the surface of the first region of the first detection mass block is released to form a third insulating layer located on the surface of the second region of the first detection mass block and a portion of the surface of the first region of the first detection mass block, a third gap between the first detection mass block and the first detection electrode, and a fourth gap between the first detection mass block and the second detection electrode.

[0080] Optionally, forming the fourth insulating layer includes:

[0081] A patterned third sacrificial insulating layer is grown on the surface of the first detection electrode, the second detection electrode, and a portion of the third insulating layer;

[0082] The third sacrificial insulating layer located on the surfaces of the first and second detection electrodes is released to form a fourth insulating layer located on a portion of the surface of the third insulating layer, a fifth gap between the second detection mass block and the first detection electrode, and a sixth gap between the second detection mass block and the second detection electrode.

[0083] The accelerometer and its manufacturing method provided in this application include a first capacitor, a second capacitor, a third capacitor, and a fourth capacitor located on a substrate. The first capacitor includes a second detection mass block and a first detection electrode; the second capacitor includes a first detection mass block and a first detection electrode; the third capacitor includes a second detection mass block and a second detection electrode; and the fourth capacitor includes a first detection mass block and a second detection electrode. The first and second detection electrodes are located between the first and second detection mass blocks, and are independent of each other and located on the same plane. This application uses the first and second detection mass blocks, along with the first and second detection electrodes located between them, to form a full-bridge capacitive sensing structure. This effectively reduces parasitic capacitance, optimizes noise, and improves stability and sensitivity, thereby ensuring that the accelerometer can effectively and quickly detect motion and attitude information. Furthermore, since the first and second detection electrodes are located between the two detection mass blocks and are independently arranged on the same plane, the electric field distribution is more uniform, effectively reducing the influence of edge effects and parasitic capacitance.

[0084] Furthermore, the second capacitor and the first capacitor are stacked along the first direction, and the fourth capacitor and the third capacitor are stacked along the first direction, reducing the size of the chip along the second direction. This allows for a greater number of accelerometer chips to be produced on a single wafer, reducing production costs.

[0085] Furthermore, this application uses a first insulating layer, a second insulating layer, a third insulating layer, and a fourth insulating layer to separate the substrate, the first detection mass block, the detection electrode, and the second detection mass block from each other, forming a full-bridge capacitor structure. This not only achieves electrical isolation and mechanical support between the upper and lower mass blocks but also ensures a stable and controllable gap between each capacitor plate, thereby improving the stability of the device. This structure allows the two detection mass blocks to tilt collaboratively under external acceleration excitation, resulting in a differential change in the paired capacitors and improving the detection accuracy of the accelerometer.

[0086] Furthermore, the first detection mass block and the second detection mass block of this application have opposite polarities, and the first detection electrode and the second detection electrode are symmetrical about the central axis of the accelerometer, which can reduce or eliminate the influence of substrate deformation on the detection results and further improve the sensitivity of the accelerometer.

[0087] Furthermore, the projected areas of the plates of the first and second capacitors are equal, and the corresponding projected areas of the third and fourth capacitors are consistent. The projected areas of the plates of different capacitors on the same mass block are symmetrical and equal, which can reduce the influence of common-mode error and temperature drift.

[0088] Furthermore, the first, second, and third openings on the two detection mass blocks not only help release stress during the manufacturing process but also enhance response sensitivity under minute accelerations. Attached Figure Description

[0089] The above and other objects, features and advantages of this application will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0090] Figure 1 A schematic diagram of the structure of an acceleration sensor provided according to an embodiment of this application is shown;

[0091] Figure 2 This diagram illustrates a capacitance detection method for an accelerometer provided according to an embodiment of this application.

[0092] Figure 3 This diagram illustrates another capacitance detection schematic of an accelerometer provided according to an embodiment of this application;

[0093] Figures 4a-4i The diagram shows the structural schematics of each stage of the manufacturing method of the accelerometer provided according to an embodiment of this application. Detailed Implementation

[0094] Various embodiments of the present application will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements are indicated by the same or similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale.

[0095] The specific implementation methods of this application will be further described in detail below with reference to the accompanying drawings and embodiments.

[0096] Figure 1 A schematic diagram of the structure of an acceleration sensor provided according to an embodiment of this application is shown. Figure 2 This diagram illustrates a capacitance detection method for an accelerometer provided according to an embodiment of this application. Figure 3 This diagram illustrates another capacitance detection schematic of an accelerometer provided according to an embodiment of this application.

[0097] like Figure 1 As shown, the accelerometer includes a first capacitor C1, a second capacitor C2, a third capacitor C3, and a fourth capacitor C4 located on the substrate 100. The first capacitor C1 includes a second detection mass block 204 and a first detection electrode 203a; the second capacitor C2 includes a first detection mass block 202 and a first detection electrode 203a; the third capacitor C3 includes a second detection mass block 204 and a second detection electrode 203b; and the fourth capacitor C4 includes a first detection mass block 202 and a second detection electrode 203b.

[0098] The first detection electrode 203a and the second detection electrode 203b are located between the first detection mass block 202 and the second detection mass block 204. The first detection electrode 203a and the second detection electrode 203b are independent of each other and are located on the same plane.

[0099] For example, the first detection electrode 203a forms a first capacitor C1 and a second capacitor C2 with the second detection mass block 204 and the first detection mass block 202, respectively, and the second detection electrode 203b forms a third capacitor C3 and a fourth capacitor C4 with the second detection mass block 204 and the first detection mass block 202, respectively.

[0100] Furthermore, the second capacitor C2 and the first capacitor C1 are stacked along the first direction, and the fourth capacitor C4 and the third capacitor C3 are stacked along the first direction.

[0101] Furthermore, the first capacitor C1 and the third capacitor C3 are arranged along the second direction, and the second capacitor C2 and the fourth capacitor C4 are arranged along the second direction.

[0102] Furthermore, the accelerometer also includes a first insulating layer 101, a wiring layer 201, and a second insulating layer 102.

[0103] The first insulating layer 101 includes a central region 101b and an edge region 101a. The first insulating layer 101 is located between the substrate 100 and the first detection mass block 202, and the central region 101b of the first insulating layer 101 contacts a portion of the first detection mass block 202 to support the first detection mass block 202.

[0104] The wiring layer 201 is located on the edge region 101a of the first insulating layer 101, and the wiring layer 201 and the first detection quality block 202 have a first gap 601 along the second direction.

[0105] The second insulating layer 102 is located on a portion of the wiring layer 201 to form a second gap 602 between the wiring layer 201 and the first detection quality block 202 along a first direction.

[0106] Furthermore, the accelerometer also includes a third insulating layer 103 and a fourth insulating layer 104.

[0107] The third insulating layer 103 is located on a portion of the first detection mass block 202, and the portion of the third insulating layer 103 is located between the first detection mass block 202 and the first detection electrode 203a, and between the first detection mass block 202 and the second detection electrode 203b, so that a third gap 603 is formed between the first detection mass block 202 and the first detection electrode 203a, and a fourth gap 604 is formed between the first detection mass block 202 and the second detection electrode 203b.

[0108] The fourth insulating layer 104 is located between a portion of the third insulating layer 103 and a portion of the second detection mass block 202. The stacked fourth insulating layer 104 and third insulating layer 103 separate the first detection mass block 202 and the second detection mass block 204 along a first direction, and a fifth gap 605 is formed between the second detection mass block 204 and the first detection electrode 203a, and a sixth gap 606 is formed between the second detection mass block 204 and the second detection electrode 203b.

[0109] Furthermore, the fourth insulating layer 104 has a first distance from the first detection electrode 203a along the second direction, and the fourth insulating layer 104 has a second distance from the second detection electrode 203b along the second direction, and the first distance and the second distance are equal.

[0110] Further, the substrate 100 serves as the base of the accelerometer. The wiring layer 201, the first detection mass block 202, the detection electrode 203, and the second detection mass block 204 are, for example, polycrystalline layers. The wiring layer 201 is electrically isolated from the substrate 100 via the first insulating layer 101. The first detection mass block 202 and the second detection mass block 204 are electrically isolated via the third insulating layer 103 and the fourth insulating layer 104. The detection electrode 203, the first detection mass block 202, and the second detection mass block 204 form a parallel-plate full-bridge capacitive sensing structure. Exemplarily, the first detection mass block 202 is parallel to the first detection electrode 203a and the second detection electrode 203b, while the second detection mass block 204 is parallel to both the first and second detection electrodes 203a and 203b.

[0111] Furthermore, the first and second detection electrodes are symmetrical about the central axis of the accelerometer.

[0112] Furthermore, the upper plate region of the first capacitor in the second detection mass block, which is opposite to the first detection electrode, has a first vertical projection, and the lower plate region of the second capacitor in the first detection mass block, which is opposite to the first detection electrode, has a second vertical projection. The areas of the first vertical projection and the second vertical projection are equal.

[0113] Furthermore, the upper plate region of the third capacitor in the second detection mass block, which is opposite to the second detection electrode, has a third vertical projection, and the lower plate region of the fourth capacitor in the first detection mass block, which is opposite to the second detection electrode, has a fourth vertical projection. The areas of the third vertical projection and the fourth vertical projection are equal.

[0114] Furthermore, the upper plate region of the first capacitor in the second detection mass block, which is opposite to the first detection electrode, has a first vertical projection, and the upper plate region of the third capacitor in the second detection mass block, which is opposite to the second detection electrode, has a third vertical projection, the area of ​​the third vertical projection being equal to the area of ​​the first vertical projection.

[0115] Furthermore, the lower plate region of the second capacitor in the first detection mass block, which is opposite to the first detection electrode, has a second vertical projection, and the lower plate region of the fourth capacitor in the first detection mass block, which is opposite to the second detection electrode, has a fourth vertical projection. The areas of the second vertical projection and the fourth vertical projection are equal.

[0116] Furthermore, the first detection mass block 202 and the second detection mass block 204 have opposite polarities.

[0117] Furthermore, the second detection mass block 204 is provided with a second opening 301, which separates the upper plate region of the first capacitor C1 in the second detection mass block 204 that is opposite to the first detection electrode 203a, and the upper plate region of the third capacitor C3 in the second detection mass block 204 that is opposite to the second detection electrode 203b. The second opening 301 is close to the first detection electrode or close to the second detection electrode.

[0118] Furthermore, the first detection mass block 202 is provided with a first opening 302, which separates the lower electrode region of the second capacitor C2, which is opposite to the first detection electrode 203a, and the lower electrode region of the fourth capacitor C4, which is opposite to the second detection electrode 203b, in the first detection mass block 202. The first opening 302 is close to the first detection electrode or close to the second detection electrode.

[0119] Furthermore, the first opening 302 corresponds to the second opening 301.

[0120] Furthermore, the first detection mass block 202 is also provided with a third opening 303, which divides the first detection mass block 202 into a first region 202b and a second region 202a. The first region 202b includes at least the lower electrode region of the second capacitor C2 and the lower electrode region of the fourth capacitor C4, and the first opening 302 is located in the first region 202b. The second region 202a is used to support the first detection electrode and the second detection electrode, and a third insulating layer 103 is provided between the second region 202a of the first detection mass block 202 and the first detection electrode and the second detection electrode.

[0121] like Figure 1As shown, a first capacitor C1 is formed in the second detection mass block 204 (RS) opposite to the first detection electrode 203a. A third capacitor C3 is formed in the second detection mass block 204 (RS) opposite to the second detection electrode 203b. A second capacitor C2 is formed in the first detection mass block 202 (-RS) opposite to the first detection electrode 203a. A fourth capacitor C4 is formed in the first detection mass block 202 (-RS) opposite to the second detection electrode 203b.

[0122] The output of the full-bridge capacitive sensing structure of the accelerometer is (expressed as charge change):

[0123] △Q=RS×(C1-C3)-RS×(C2-C4)=RS×(C1-C2-C3+C4)

[0124] like Figure 2 As shown, when the substrate 100 deforms, it causes the detection electrode 203 to deform, resulting in displacement of the wiring in the detection electrode 203. This causes changes in the capacitances C1, C2, C3, and C4 formed by the electrode, the second detection mass block RS, and the first detection mass block RS. At this time, the output of the full-bridge capacitive detection structure of the accelerometer is (expressed as charge change):

[0125] △Q1=RS×(C1+△C1-C3-△C3)-RS×(C2+△C2-C4-△C4)=

[0126] RS×(C1-C2-C3+C4)+RS×(△C1-△C2-△C3+△C4)

[0127] Where △C1=△C2, △C3=△C4, the above equation can be simplified to:

[0128] △Q1=RS×(C1-C2-C3+C4)+RS×(△C1-△C2-△C3+△C4)=

[0129] RS×(C1-C2-C3+C4)

[0130] In other words, the accelerometer provided in this application can reduce or even eliminate the influence of substrate deformation on the detection signal.

[0131] like Figure 3 As shown, when the first detection mass block 202 tilts toward the first detection electrode 203a and simultaneously causes the second detection mass block 204 to tilt toward the second detection electrode 203b, the first capacitor C1 and the fourth capacitor C4 decrease, while the second capacitor C2 and the third capacitor C3 increase.

[0132] In other embodiments, when the first detection mass block 202 tilts toward the second detection electrode 203b and simultaneously causes the second detection mass block 204 to tilt toward the first detection electrode 203a, the first capacitor C1 and the fourth capacitor C4 increase, while the second capacitor C2 and the third capacitor C3 decrease.

[0133] Figures 4a-4i The diagram shows the structural schematics of each stage of the manufacturing method of the accelerometer provided according to an embodiment of this application.

[0134] like Figure 4a As shown, a substrate 100 is provided. The substrate 100 is, for example, a silicon substrate, and the crystal orientation of the silicon substrate can be selected from crystal orientations such as 100 and 110 according to design requirements.

[0135] like Figure 4b As shown, a first insulating layer 101 is formed. A first insulating layer 101 with a thickness of approximately 2 μm is grown on the surface of the substrate 100. The first insulating layer 101 can be selected from silicon oxide, silicon nitride, etc., depending on requirements and design. The fabrication process of the first insulating layer 101 can be thermal oxidation, CVD, etc. In alternative embodiments, an SOI wafer can be directly selected, omitting this step.

[0136] like Figure 4c As shown, in other embodiments, a wiring layer 201 is also formed. A first polycrystalline layer is formed on the first insulating layer 101, for example, using a PECVD process, and a patterned wiring layer 201 is formed by a photolithography etching process. The thickness of the wiring layer 201 is, for example, 1 μm or less; exemplarily, the thickness of the wiring layer 201 is, for example, about 0.8 μm.

[0137] like Figure 4d As shown, a first sacrificial insulating layer 502 is formed. The first sacrificial insulating layer 502 undergoes subsequent processes to form a second insulating layer 102. In... Figure 4c A first sacrificial insulating layer 502 is grown on the surface of the structure shown (on the surface of wiring layer 201 and part of the first insulating layer 101) and patterned by photolithography etching to leave a connection window for the first detection quality block 202. This first sacrificial insulating layer 502 also serves as a sacrificial release layer, which needs to be fumigated and released in subsequent processes to form a cavity. The first sacrificial insulating layer 502 is, for example, a silicon oxide insulating layer with a thickness of approximately 1.5 μm.

[0138] like Figure 4e As shown, a first detection quality block 202 is formed. In the case of... Figure 4dA second polycrystalline layer is epitaxially grown on the surface of the structure shown (the surface of the first sacrificial insulating layer 502 and part of the first insulating layer 101), and a first detection mass block 202 (-RS) is formed by photolithography etching. The thickness of the first detection mass block 202 is approximately 20 μm. Further, the first detection mass block 202 is provided with a first opening 302 and a third opening 303. The first opening 302 separates the lower electrode region of the second capacitor C2, which is opposite to the first detection electrode, and the lower electrode region of the fourth capacitor C4, which is opposite to the second detection electrode, in the first detection mass block 202. The third opening 303 divides the first detection mass block 202 into a first region 202b and a second region 202a. The first region 202b includes at least the lower electrode region of the second capacitor C2 and the lower electrode region of the fourth capacitor C4, and the first opening 302 is located in the first region 202b. The second region 202a is used to support the first detection electrode and the second detection electrode, and a third insulating layer 103 is provided between the second region 202a and the first detection electrode and the second detection electrode.

[0139] like Figure 4f As shown, a second sacrificial insulating layer 503 is formed. In the case of... Figure 4e An insulating layer is grown integrally on the surface of the structure shown, and a second sacrificial insulating layer 503 is formed on the surface of the first detection mass block 202 by photolithography etching. The second sacrificial insulating layer 503 also serves as a sacrificial release layer, which needs to be released by fumigation in subsequent processes to form a cavity. The second sacrificial insulating layer 503 is, for example, a silicon oxide insulating layer with a thickness of approximately 1.5 μm.

[0140] like Figure 4g As shown, a first detection electrode 203a and a second detection electrode 203b are formed. In... Figure 4f On the surface of the structure shown, a third polycrystalline layer is epitaxially grown, and a first detection electrode 203a and a second detection electrode 203b are patterned using a photolithography etching process. The thickness of the first detection electrode 203a and the second detection electrode 203b is approximately 1.5 μm.

[0141] like Figure 4h As shown, a third sacrificial insulating layer 504 is formed. In... Figure 4g The surface of the structure shown is integrally grown with an insulating layer, and patterned using photolithography to leave a connection window for the second detection quality block 204. The third sacrificial insulating layer 504 also serves as a sacrificial release layer, which needs to be fumigated and released in subsequent processes to form a cavity. The third sacrificial insulating layer 504 is, for example, a silicon oxide insulating layer with a thickness of approximately 1.5 μm.

[0142] like Figure 4i As shown, a second detection quality block 204 is formed. In... Figure 4hA fourth polycrystalline layer is epitaxially grown on the surface of the structure shown, and a second detection mass block 204 (RS) is formed by photolithography etching. The thickness of the second detection mass block 204 is approximately 20 μm. Further, a second opening 301 is provided on the second detection mass block 204, which separates the upper electrode region of the first capacitor C1, which is opposite to the first detection electrode 203a, and the upper electrode region of the third capacitor C3, which is opposite to the second detection electrode 203b. Further, the first opening 302 is close to either the first detection electrode 203a or the second detection electrode 203b. Further, the second opening 301 is close to either the first detection electrode 203a or the second detection electrode 203b. Further, the first opening 302 and the second opening 301 correspond to each other.

[0143] Further, see Figure 1 Through a vacuum chamber fumigation release process, the silicon oxide sacrificial insulating layer is released by fumigation, forming a cavity structure and a patterned second insulating layer, third insulating layer, and fourth insulating layer. This realizes the parallel plate movement space between the first detection electrode, the second detection electrode, the first detection mass block - RS, and the second detection mass block RS, forming the first capacitor C1, the third capacitor C3, the second capacitor C2, and the fourth capacitor C4.

[0144] Furthermore, the fumigation-released silicon dioxide sacrificial insulation layer includes:

[0145] Release the first sacrificial insulating layer located on the surface of the first insulating layer 101 and a portion of the first sacrificial insulating layer 502 located on the surface of the wiring layer to form a second insulating layer 102 supporting the second region 202a of the first detection mass block 202, a first gap 601 between the wiring layer 201 and the first detection mass block 202 along the second direction, and a second gap 602 between the wiring layer 201 and the first detection mass block 202 along the first direction.

[0146] A portion of the second sacrificial insulating layer 503 located on the surface of the first region 202b of the first detection mass block 202 is released to form a third insulating layer 103 located on the surface of the second region 202a of the first detection mass block 202 and a portion of the surface of the first region 202b of the first detection mass block 202, a third gap 603 between the first detection mass block 202 and the first detection electrode 203a, and a fourth gap 604 between the first detection mass block 202 and the second detection electrode 203b;

[0147] The third sacrificial insulating layer 504 located on the surfaces of the first detection electrode 203a and the second detection electrode 203b is released to form a fourth insulating layer located on a portion of the surface of the third insulating layer 103, a fifth gap 605 between the second detection mass block 204 and the first detection electrode 203a, and a sixth gap 606 between the second detection mass block 204 and the second detection electrode 203b.

[0148] Furthermore, the fourth insulating layer 104 has a first distance from the first detection electrode 203a along the second direction, and the fourth insulating layer 104 has a second distance from the second detection electrode 203b along the second direction, and the first distance and the second distance are equal.

[0149] Furthermore, the upper plate region of the first capacitor in the second detection mass block, which is opposite to the first detection electrode, has a first vertical projection, and the lower plate region of the second capacitor in the first detection mass block, which is opposite to the first detection electrode, has a second vertical projection. The areas of the first vertical projection and the second vertical projection are equal.

[0150] Furthermore, the upper plate region of the third capacitor in the second detection mass block, which is opposite to the second detection electrode, has a third vertical projection, and the lower plate region of the fourth capacitor in the first detection mass block, which is opposite to the second detection electrode, has a fourth vertical projection. The areas of the third vertical projection and the fourth vertical projection are equal.

[0151] Furthermore, the upper plate region of the first capacitor in the second detection mass block, which is opposite to the first detection electrode, has a first vertical projection, and the upper plate region of the third capacitor in the second detection mass block, which is opposite to the second detection electrode, has a third vertical projection, the area of ​​the third vertical projection being equal to the area of ​​the first vertical projection.

[0152] Furthermore, the lower plate region of the second capacitor in the first detection mass block, which is opposite to the first detection electrode, has a second vertical projection, and the lower plate region of the fourth capacitor in the first detection mass block, which is opposite to the second detection electrode, has a fourth vertical projection. The areas of the second vertical projection and the fourth vertical projection are equal.

[0153] Furthermore, the first detection mass block is parallel to the first detection electrode, the first detection mass block is parallel to the second detection electrode, the second detection mass block is parallel to the first detection electrode, and the second detection mass block is parallel to the second detection electrode.

[0154] Furthermore, the first and second detection electrodes are symmetrical about the central axis of the accelerometer.

[0155] Furthermore, when the first detection mass block tilts toward the first detection electrode and simultaneously causes the second detection mass block to tilt toward the second detection electrode, the first capacitor and the fourth capacitor decrease, while the second capacitor and the third capacitor increase.

[0156] Furthermore, when the first detection mass block tilts toward the second detection electrode and simultaneously causes the second detection mass block to tilt toward the first detection electrode, the first capacitor and the fourth capacitor increase, while the second capacitor and the third capacitor decrease.

[0157] The accelerometer and its manufacturing method provided in this application include a first capacitor, a second capacitor, a third capacitor, and a fourth capacitor located on a substrate. The first capacitor includes a second detection mass block and a first detection electrode; the second capacitor includes a first detection mass block and a first detection electrode; the third capacitor includes a second detection mass block and a second detection electrode; and the fourth capacitor includes a first detection mass block and a second detection electrode. The first and second detection electrodes are located between the first and second detection mass blocks, and are independent of each other and located on the same plane. This application uses the first and second detection mass blocks, along with the first and second detection electrodes located between them, to form a full-bridge capacitive sensing structure. This effectively reduces parasitic capacitance, optimizes noise, and improves stability and sensitivity, thereby ensuring that the accelerometer can effectively and quickly detect motion and attitude information. Furthermore, since the first and second detection electrodes are located between the two detection mass blocks and are independently arranged on the same plane, the electric field distribution is more uniform, effectively reducing the influence of edge effects and parasitic capacitance.

[0158] Furthermore, the second capacitor and the first capacitor are stacked along the first direction, and the fourth capacitor and the third capacitor are stacked along the first direction, reducing the size of the chip along the second direction. This allows for a greater number of accelerometer chips to be produced on a single wafer, reducing production costs.

[0159] Furthermore, this application uses a first insulating layer, a second insulating layer, a third insulating layer, and a fourth insulating layer to separate the substrate, the first detection mass block, the detection electrode, and the second detection mass block from each other, forming a full-bridge capacitor structure. This not only achieves electrical isolation and mechanical support between the upper and lower mass blocks but also ensures a stable and controllable gap between each capacitor plate, thereby improving the stability of the device. This structure allows the two detection mass blocks to tilt collaboratively under external acceleration excitation, resulting in a differential change in the paired capacitors and improving the detection accuracy of the accelerometer.

[0160] Furthermore, the first detection mass block and the second detection mass block of this application have opposite polarities, and the first detection electrode and the second detection electrode are symmetrical about the central axis of the accelerometer, which can reduce or eliminate the influence of substrate deformation on the detection results and further improve the sensitivity of the accelerometer.

[0161] Furthermore, the projected areas of the plates of the first and second capacitors are equal, and the corresponding projected areas of the third and fourth capacitors are consistent. The projected areas of the plates of different capacitors on the same mass block are symmetrical and equal, which can reduce the influence of common-mode error and temperature drift.

[0162] Furthermore, the first, second, and third openings on the two detection mass blocks not only help release stress during the manufacturing process but also enhance response sensitivity under minute accelerations.

[0163] As described above, these embodiments of this application do not exhaustively cover all details, nor do they limit the application to merely the specific embodiments described. Clearly, many modifications and variations can be made based on the above description. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this application, thereby enabling those skilled in the art to effectively utilize this application and its modifications. This application is limited only by the claims and their full scope and equivalents.

Claims

1. An acceleration sensor, wherein, include: The first capacitor, the second capacitor, the third capacitor, and the fourth capacitor are located on the substrate. The first capacitor includes a second detection mass block and a first detection electrode. The second capacitor includes a first detection mass block and a first detection electrode. The third capacitor includes a second detection mass block and a second detection electrode. The fourth capacitor includes a first detection mass block and a second detection electrode. The first detection electrode and the second detection electrode are located between the first detection mass block and the second detection mass block, and the first detection electrode and the second detection electrode are independent of each other and located on the same plane.

2. The acceleration sensor according to claim 1, wherein, The second capacitor and the first capacitor are stacked together along the first direction, and the fourth capacitor and the third capacitor are stacked together along the first direction.

3. The acceleration sensor according to claim 1 or 2, wherein, The first capacitor and the third capacitor are arranged along the second direction, and the second capacitor and the fourth capacitor are arranged along the second direction, which is perpendicular to the first direction.

4. The acceleration sensor according to claim 1, wherein, Also includes: A first insulating layer is located between the substrate and the first detection mass block, and a portion of the first insulating layer contacts the first detection mass block to support the first detection mass block.

5. The acceleration sensor according to claim 4, wherein, Also includes: A wiring layer is located on the edge region of the first insulating layer, and the wiring layer and the first detection mass block have a first gap along the second direction; as well as A second insulating layer is located on a portion of the wiring layer to create a second gap between the wiring layer and the first detection quality block along a first direction.

6. The acceleration sensor according to claim 1, wherein, Also includes: A third insulating layer is located on a portion of the first detection mass block, and a portion of the third insulating layer is located between the first detection mass block and the first detection electrode, and between the first detection mass block and the second detection electrode, so as to create a third gap between the first detection mass block and the first detection electrode, and to create a fourth gap between the first detection mass block and the second detection electrode. as well as A fourth insulating layer is located between a portion of the third insulating layer and a portion of the second detection mass block. The stacked fourth and third insulating layers separate the first and second detection mass blocks along a first direction and provide a fifth gap between the second detection mass block and the first detection electrode, and a sixth gap between the second detection mass block and the second detection electrode.

7. The acceleration sensor according to claim 6, wherein, The fourth insulating layer has a first distance from the first detection electrode along the second direction, and the fourth insulating layer has a second distance from the second detection electrode along the second direction, wherein the first distance and the second distance are equal.

8. The acceleration sensor according to claim 1, wherein, The upper plate region of the first capacitor in the second detection mass block, which is opposite to the first detection electrode, has a first vertical projection, and the lower plate region of the second capacitor in the first detection mass block, which is opposite to the first detection electrode, has a second vertical projection. The areas of the first vertical projection and the second vertical projection are equal.

9. The acceleration sensor according to claim 1, wherein, The upper plate region of the third capacitor in the second detection mass block, which is opposite to the second detection electrode, has a third vertical projection, and the lower plate region of the fourth capacitor in the first detection mass block, which is opposite to the second detection electrode, has a fourth vertical projection. The areas of the third vertical projection and the fourth vertical projection are equal.

10. The acceleration sensor according to claim 1, wherein, The upper plate region of the first capacitor in the second detection mass block, which is opposite to the first detection electrode, has a first vertical projection, and the upper plate region of the third capacitor in the second detection mass block, which is opposite to the second detection electrode, has a third vertical projection, the area of ​​which is equal to that of the first vertical projection.

11. The acceleration sensor according to claim 1, wherein, The lower plate region of the second capacitor in the first detection mass block, which is opposite to the first detection electrode, has a second vertical projection, and the lower plate region of the fourth capacitor in the first detection mass block, which is opposite to the second detection electrode, has a fourth vertical projection. The areas of the second vertical projection and the fourth vertical projection are equal.

12. The acceleration sensor according to claim 1, wherein, The first detection mass block has a first opening, which is close to the first detection electrode or close to the second detection electrode.

13. The acceleration sensor according to claim 12, wherein, The second detection mass block has a second opening, which is close to the first detection electrode or close to the second detection electrode.

14. The acceleration sensor according to claim 13, wherein, The second opening corresponds to the first opening.

15. The acceleration sensor according to claim 12, wherein, The first detection mass block also has a third opening, which divides the first detection mass block into a first region and a second region. The first region includes at least the lower plate region of the second capacitor and the lower plate region of the fourth capacitor, and the first opening is located in the first region. The second region is used to support the first detection electrode and the second detection electrode, and a third insulating layer is provided between the second region of the first detection mass block and the first detection electrode and the second detection electrode.

16. The acceleration sensor according to claim 1, wherein, The first detection mass block is parallel to the first detection electrode, the first detection mass block is parallel to the second detection electrode, the second detection mass block is parallel to the first detection electrode, and the second detection mass block is parallel to the second detection electrode.

17. The acceleration sensor according to claim 1, wherein, The first detection electrode and the second detection electrode are symmetrical about the central axis of the accelerometer.

18. The acceleration sensor according to claim 1, wherein, When the first detection mass block tilts toward the first detection electrode and simultaneously causes the second detection mass block to tilt toward the second detection electrode, the first capacitor and the fourth capacitor decrease, while the second capacitor and the third capacitor increase.

19. The acceleration sensor according to claim 1, wherein, When the first detection mass block tilts toward the second detection electrode and simultaneously causes the second detection mass block to tilt toward the first detection electrode, the first capacitor and the fourth capacitor increase, while the second capacitor and the third capacitor decrease.

20. A method for manufacturing an accelerometer, wherein, include: A first capacitor, a second capacitor, a third capacitor, and a fourth capacitor are formed on the substrate. The first capacitor includes a second detection mass block and a first detection electrode. The second capacitor includes a first detection mass block and a first detection electrode. The third capacitor includes a second detection mass block and a second detection electrode. The fourth capacitor includes a first detection mass block and a second detection electrode. The first detection electrode and the second detection electrode are located between the first detection mass block and the second detection mass block, and the first detection electrode and the second detection electrode are independent of each other and located on the same plane.

21. The method for manufacturing an accelerometer according to claim 20, wherein, The second capacitor and the first capacitor are stacked together along the first direction, and the fourth capacitor and the third capacitor are stacked together along the first direction.

22. The method for manufacturing an acceleration sensor according to claim 20 or 21, wherein, The first capacitor and the third capacitor are arranged along the second direction, and the second capacitor and the fourth capacitor are arranged along the second direction, which is perpendicular to the first direction.

23. The method for manufacturing an accelerometer according to claim 20, wherein, Also includes: A first insulating layer is formed between the substrate and the first detection mass block, and a portion of the first insulating layer contacts the first detection mass block to support the first detection mass block.

24. The method for manufacturing an accelerometer according to claim 23, wherein, Also includes: A wiring layer is formed on the edge region of the first insulating layer, and the wiring layer has a first gap with the first detection mass block along the second direction; as well as A second insulating layer is formed on a portion of the wiring layer to create a second gap between the wiring layer and the first detection mass block along a first direction.

25. The method for manufacturing an accelerometer according to claim 20, wherein, Also includes: A third insulating layer is formed on a portion of the first detection mass block, the portion of the third insulating layer being located between the first detection mass block and the first detection electrode, and between the first detection mass block and the second detection electrode, to create a third gap between the first detection mass block and the first detection electrode, and a fourth gap between the first detection mass block and the second detection electrode; and A fourth insulating layer is formed between a portion of the third insulating layer and a portion of the second detection mass block. The stacked fourth insulating layer and the third insulating layer separate the first detection mass block and the second detection mass block along a first direction, and a fifth gap is formed between the second detection mass block and the first detection electrode, and a sixth gap is formed between the second detection mass block and the second detection electrode.

26. The method for manufacturing an accelerometer according to claim 25, wherein, The fourth insulating layer has a first distance from the first detection electrode along the second direction, and the fourth insulating layer has a second distance from the second detection electrode along the second direction, wherein the first distance and the second distance are equal.

27. The method for manufacturing an accelerometer according to claim 20, wherein, The upper plate region of the first capacitor in the second detection mass block, which is opposite to the first detection electrode, has a first vertical projection, and the lower plate region of the second capacitor in the first detection mass block, which is opposite to the first detection electrode, has a second vertical projection. The areas of the first vertical projection and the second vertical projection are equal.

28. The method for manufacturing an accelerometer according to claim 20, wherein, The upper plate region of the third capacitor in the second detection mass block, which is opposite to the second detection electrode, has a third vertical projection, and the lower plate region of the fourth capacitor in the first detection mass block, which is opposite to the second detection electrode, has a fourth vertical projection. The areas of the third vertical projection and the fourth vertical projection are equal.

29. The method for manufacturing an accelerometer according to claim 20, wherein, The upper plate region of the first capacitor in the second detection mass block, which is opposite to the first detection electrode, has a first vertical projection, and the upper plate region of the third capacitor in the second detection mass block, which is opposite to the second detection electrode, has a third vertical projection, the area of ​​which is equal to that of the first vertical projection.

30. The method for manufacturing an accelerometer according to claim 20, wherein, The lower plate region of the second capacitor in the first detection mass block, which is opposite to the first detection electrode, has a second vertical projection, and the lower plate region of the fourth capacitor in the first detection mass block, which is opposite to the second detection electrode, has a fourth vertical projection. The areas of the second vertical projection and the fourth vertical projection are equal.

31. The method for manufacturing an accelerometer according to claim 20, wherein, Also includes: A first opening is formed on the first detection mass block, the first opening being close to the first detection electrode or close to the second detection electrode.

32. The method for manufacturing an accelerometer according to claim 31, wherein, Also includes: A second opening is formed on the second detection mass block, the second opening being close to the first detection electrode or close to the second detection electrode.

33. The method for manufacturing an accelerometer according to claim 32, wherein, The second opening corresponds to the first opening.

34. The method for manufacturing an accelerometer according to claim 31, wherein, Also includes: A third opening is formed on the first detection mass block, the third opening dividing the first detection mass block into a first region and a second region. The first region includes at least the lower plate region of the second capacitor and the lower plate region of the fourth capacitor, and the first opening is located in the first region. The second region is used to support the first detection electrode and the second detection electrode, and a third insulating layer is provided between the second region of the first detection mass block and the first detection electrode and the second detection electrode.

35. The method for manufacturing an accelerometer according to claim 20, wherein, The first detection mass block is parallel to the first detection electrode, the first detection mass block is parallel to the second detection electrode, the second detection mass block is parallel to the first detection electrode, and the second detection mass block is parallel to the second detection electrode.

36. The method for manufacturing an accelerometer according to claim 20, wherein, The first detection electrode and the second detection electrode are symmetrical about the central axis of the accelerometer.

37. The method for manufacturing an accelerometer according to claim 20, wherein, When the first detection mass block tilts toward the first detection electrode and simultaneously causes the second detection mass block to tilt toward the second detection electrode, the first capacitor and the fourth capacitor decrease, while the second capacitor and the third capacitor increase.

38. The method for manufacturing an accelerometer according to claim 20, wherein, When the first detection mass block tilts toward the second detection electrode and simultaneously causes the second detection mass block to tilt toward the first detection electrode, the first capacitor and the fourth capacitor increase, while the second capacitor and the third capacitor decrease.

39. The method for manufacturing an accelerometer according to claim 24, wherein, Forming a second insulating layer on a portion of the wiring layer includes: A patterned first sacrificial insulating layer is grown on the surface of the wiring layer and a portion of the first insulating layer to leave a connection window for the first detection quality block; Release the first sacrificial insulating layer located on the surface of the first insulating layer and a portion of the first sacrificial insulating layer located on the surface of the wiring layer to form a second insulating layer supporting the second region of the first detection mass block, a first gap between the wiring layer and the first detection mass block along the second direction, and a second gap between the wiring layer and the first detection mass block along the first direction.

40. The method for manufacturing an accelerometer according to claim 25, wherein, The formation of the third insulating layer includes: A patterned second sacrificial insulating layer is grown on the surface of the first detection mass block; A portion of the second sacrificial insulating layer located on the surface of the first region of the first detection mass block is released to form a third insulating layer located on the surface of the second region of the first detection mass block and a portion of the surface of the first region of the first detection mass block, a third gap between the first detection mass block and the first detection electrode, and a fourth gap between the first detection mass block and the second detection electrode.

41. The method for manufacturing an accelerometer according to claim 25, wherein, The formation of the fourth insulating layer includes: A patterned third sacrificial insulating layer is grown on the surface of the first detection electrode, the second detection electrode, and a portion of the third insulating layer; The third sacrificial insulating layer located on the surfaces of the first and second detection electrodes is released to form a fourth insulating layer located on a portion of the surface of the third insulating layer, a fifth gap between the second detection mass block and the first detection electrode, and a sixth gap between the second detection mass block and the second detection electrode.

Images