CN113120855A - Preparation method of cavity structure and micro-electro-mechanical system sensor - Google Patents
Preparation method of cavity structure and micro-electro-mechanical system sensor Download PDFInfo
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- CN113120855A CN113120855A CN202110400939.7A CN202110400939A CN113120855A CN 113120855 A CN113120855 A CN 113120855A CN 202110400939 A CN202110400939 A CN 202110400939A CN 113120855 A CN113120855 A CN 113120855A
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- 238000002360 preparation method Methods 0.000 title claims abstract description 29
- 239000000758 substrate Substances 0.000 claims abstract description 43
- 239000011368 organic material Substances 0.000 claims abstract description 10
- 238000000034 method Methods 0.000 claims description 55
- 238000004519 manufacturing process Methods 0.000 claims description 15
- 238000005530 etching Methods 0.000 claims description 14
- 239000000725 suspension Substances 0.000 claims description 8
- 239000000126 substance Substances 0.000 claims description 7
- 238000005240 physical vapour deposition Methods 0.000 claims description 5
- 230000001133 acceleration Effects 0.000 claims description 3
- 239000010408 film Substances 0.000 description 29
- 239000000463 material Substances 0.000 description 17
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 6
- 229910052710 silicon Inorganic materials 0.000 description 6
- 239000010703 silicon Substances 0.000 description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000005265 energy consumption Methods 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- 238000007667 floating Methods 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 238000005498 polishing Methods 0.000 description 2
- 238000004528 spin coating Methods 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000001312 dry etching Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 238000000059 patterning Methods 0.000 description 1
- 238000001259 photo etching Methods 0.000 description 1
- 238000000206 photolithography Methods 0.000 description 1
- 229920002120 photoresistant polymer Polymers 0.000 description 1
- 238000001020 plasma etching Methods 0.000 description 1
- 238000009832 plasma treatment Methods 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
- B81B7/00—Microstructural systems; Auxiliary parts of microstructural devices or systems
- B81B7/02—Microstructural systems; Auxiliary parts of microstructural devices or systems containing distinct electrical or optical devices of particular relevance for their function, e.g. microelectro-mechanical systems [MEMS]
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
- B81B7/00—Microstructural systems; Auxiliary parts of microstructural devices or systems
- B81B7/0032—Packages or encapsulation
- B81B7/0035—Packages or encapsulation for maintaining a controlled atmosphere inside of the chamber containing the MEMS
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
- B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
- B81C1/00015—Manufacture or treatment of devices or systems in or on a substrate for manufacturing microsystems
- B81C1/00261—Processes for packaging MEMS devices
- B81C1/00277—Processes for packaging MEMS devices for maintaining a controlled atmosphere inside of the cavity containing the MEMS
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
- B81B2201/00—Specific applications of microelectromechanical systems
- B81B2201/02—Sensors
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
- B81B2203/00—Basic microelectromechanical structures
- B81B2203/01—Suspended structures, i.e. structures allowing a movement
- B81B2203/0118—Cantilevers
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- Microelectronics & Electronic Packaging (AREA)
- Manufacturing & Machinery (AREA)
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Abstract
The embodiment of the invention discloses a preparation method of a cavity structure and a micro electro mechanical system sensor, wherein the preparation method of the cavity structure comprises the steps of providing a substrate, wherein the substrate comprises a first surface and a second surface which are oppositely arranged, and the first surface is provided with a groove structure; preparing at least two planarization layers on one side of the first surface, wherein the planarization layers cover the first surface and the groove structures; the planarization layer comprises an organic material layer, and the thickness of the planarization layer on one side of the first surface is smaller than that of the planarization layer on one side of the groove structure; thinning the planarization layer to expose the first surface, and filling the groove structure with the planarization layer; preparing a suspended film on the first surface and the surface of the planarization layer, and preparing a window in the suspended film; the planarization layer in the groove structure is removed through the window, and the cavity structure is obtained.
Description
Technical Field
The embodiment of the invention relates to the technical field of micro electro mechanical systems, in particular to a preparation method of a cavity structure and a micro electro mechanical system sensor.
Background
In the field of micro-electro-mechanical systems, many micro-electro-mechanical structures are bulk structures, and a sensing device needs to be provided with a plurality of cavities.
At present, most of the structures for manufacturing the cavity film or the cantilever beam generally adopt deep silicon etching, back double-sided alignment is carried out from the back of a wafer for photoetching patterning, a deep silicon etching machine or a wet bulk silicon etching process is adopted for etching, and a back cavity is opened, so that the method has higher requirements on equipment and process precision, longer equipment time and higher machine time cost, and then a pattern with a particularly high depth-to-width ratio cannot be realized, because the inherent thickness of a common silicon wafer is about 400-600 mu m, if a window pattern is smaller, the depth-to-width ratio is more than 100: 1, the current process technology cannot be realized generally.
And a part of the cantilever beam or the film structure adopts a surface process, and the film is bonded on the sacrificial layer by using a bonding process. The process has high difficulty, firstly, the requirement on equipment is high, the machine-hour cost is high, and secondly, the yield is also influenced by the surface quality of the sacrificial layer.
In addition, some processes are surface mechanical polishing by CMP, although the precision and the surface condition are both advantageous, the surface material, thickness and the like have many requirements, so the material is not suitable for the method, the method is time-consuming and labor-consuming, and many MEMS sensor devices do not have such high roughness requirement, or some MEMS sensor devices cannot work on the surface by using some chemical polishing agent, so the method cannot be compatible with most sensor process manufacturing processes.
Disclosure of Invention
In view of this, embodiments of the present invention provide a method for manufacturing a cavity structure and a mems sensor, so as to solve the technical problems of the prior art that the manufacturing process of the cavity structure is high in cost and complex in operation.
In a first aspect, an embodiment of the present invention provides a method for preparing a cavity structure, including:
providing a substrate, wherein the substrate comprises a first surface and a second surface which are oppositely arranged, and the first surface is provided with a groove structure;
preparing at least two planarization layers on one side of the first surface, wherein the planarization layers cover the first surface and the groove structures; the planarization layer comprises an organic material layer, and the thickness of the planarization layer on one side of the first surface is smaller than that of the planarization layer on one side of the groove structure;
thinning the planarization layer to expose the first surface, wherein the planarization layer fills the groove structure;
preparing a suspension film on the first surface and the surface of the planarization layer, and preparing a window in the suspension film, wherein a vertical projection of the window on the plane of the substrate at least partially overlaps with the groove structure;
and removing the planarization layer in the groove structure through the window to obtain a cavity structure.
Optionally, at least two planarization layers are prepared on one side of the first surface, including:
preparing at least two planarization layers on one side of the first surface according to the depth-to-width ratio and the flatness requirement of the groove structure;
the planarization layer on one side of the first surface is provided with a first height h1, and the planarization layer on one side of the groove structure is provided with a second height h2, wherein | h1-h2|/h1 is less than or equal to 10%.
Optionally, the at least two planarization layers include a first planarization layer and a second planarization layer;
preparing at least two planarization layers on one side of the first surface, including:
preparing a first planarization layer on one side of the first surface, wherein the first planarization layer covers the first surface and the groove structure;
curing the first planarizing layer;
preparing a second planarization layer on the side of the first planarization layer away from the substrate, wherein the second planarization layer covers the first planarization layer;
and curing the second planarization layer.
Optionally, the thickness d of the first planarizing layer satisfies that d is greater than or equal to 1 μm and less than or equal to 2 μm.
Optionally, after the curing the first planarization layer, the method further includes:
and carrying out hydrophilic treatment on the first planarization layer.
Optionally, performing hydrophilic treatment on the first planarization layer, including:
carrying out hydrophilic treatment on the first planarization layer by adopting a first preset temperature; the first preset temperature is lower than the curing temperature of the first planarization layer.
Optionally, thinning the planarization layer to expose the first surface includes:
thinning the planarization layer by adopting dry chemical vapor etching at a second preset temperature to expose the first surface; the second preset temperature is less than the curing temperature of the planarization layer.
Optionally, preparing a suspended film on the first surface and the surface of the planarization layer includes:
preparing suspended films on the first surface and the surface of the planarization layer at a third preset temperature by adopting physical vapor deposition; the third preset temperature is less than the curing temperature of the planarization layer.
In a second aspect, an embodiment of the present invention further provides a mems sensor, including a substrate, a cavity structure located in the substrate, and a suspended film located on a side of the cavity structure away from the substrate;
the cavity structure is prepared by the preparation method of the first aspect.
Optionally, the mems sensor includes at least one of a mems pressure sensor, an infrared thermopile sensor, a mems acceleration sensor, a mems micromirror sensor, and a mems gyroscope sensor.
According to the preparation method of the cavity structure, provided by the embodiment of the invention, the plurality of flat layers are covered on the substrate with the groove structure, and then the substrate is thinned to be exposed, so that the flat layers completely fill the groove structure, and the purpose of flattening is achieved; and then preparing a suspended film, and removing the filled flat layer to obtain the cavity structure. The preparation method of the cavity structure provided by the embodiment of the invention can solve the problem of pattern planarization, and has the advantages of low difficulty of the preparation process of the cavity structure, low preparation cost and high practical feasibility.
Drawings
Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments made with reference to the following drawings:
fig. 1 is a schematic flow chart of a method for manufacturing a cavity structure according to an embodiment of the present invention;
fig. 2-7 are schematic structural diagrams of steps in a method for preparing a cavity structure according to an embodiment of the present invention;
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be fully described by the detailed description with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are a part of the embodiments of the present invention, not all embodiments, and all other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without inventive efforts fall within the scope of the present invention.
Fig. 1 is a schematic flow chart of a method for manufacturing a cavity structure according to an embodiment of the present invention, and the method for manufacturing a cavity structure according to an embodiment of the present invention may be used for a cavity structure. As shown in fig. 1, the method for preparing a cavity structure provided in the embodiment of the present invention at least includes the following steps:
s110, providing a substrate, wherein the substrate comprises a first surface and a second surface which are oppositely arranged, and the first surface is provided with a groove structure.
As shown in fig. 2, the substrate 210 includes a first surface 211 and a second surface 213 disposed opposite to each other, wherein the first surface 211 may be understood as an upper surface of the substrate 210, and the second surface 213 may be understood as a lower surface of the substrate 210. The first surface 211 of the substrate 210 is provided with the groove structure 212, the depth of the groove structure 212 is not limited in the embodiment of the present invention, and the groove structure 212 may correspond to different depths in different devices.
Alternatively, the substrate 210 may be a silicon substrate or a substrate made of other materials, and the type of the substrate 210 is not limited in the embodiments of the present invention.
S120, preparing at least two planarization layers on one side of the first surface, wherein the planarization layers cover the first surface and the groove structures; the planarization layer includes an organic material layer, and a thickness of the planarization layer on the first surface side is smaller than a thickness of the planarization layer on the groove structure side.
As shown in fig. 3, at least two planarization layers 310 are prepared on the first surface 211, wherein the planarization layer 310 covers the first surface 211 and the groove structure 212. Wherein the planarization layer 310 comprises a layer of organic material comprising a colloidal polymer that can be converted between a non-polymerized state and a polymerized state. For the subsequent curing process to proceed smoothly, the planarization layer 310 may have partial fluidity, and at least two planarization layers may be prepared to planarize the surface of the substrate 210, wherein the fluidity of the planarization layer 310 causes the planarization layer 310 to move more toward the position of the groove structure 212, such that the thickness of the planarization layer 310 on the first surface 211 side is smaller than the thickness of the planarization layer 310 on the groove structure 212 side.
Optionally, the planarization layer 310 may be made of photoresist or other organic materials, and is prepared on the substrate 210 by processes such as spraying or spin coating, and the embodiment of the present invention does not limit the type of the planarization layer 310 and the coating process.
It should be noted that, in fig. 3, the planarization layer 310 includes four planarization layers (including, respectively, 311, 312, 313, and 314 disposed in a stacked manner), and the embodiment of the invention does not limit the number of specific film layers of the planarization layer 310, and only needs to ensure that at least two planarization layers are included.
S130, thinning the planarization layer to expose the first surface, and filling the groove structure with the planarization layer.
As shown in fig. 4, the planarization layer 310 is thinned to expose the first surface 211, and the planarization layer 310 fills the groove structure 212, wherein the groove structure 212 filling the planarization layer 310 may be flush or approximately flush with the first surface 211.
Further, since the substrate 210 and the planarization layer 310 are made of different materials, the thinning operation may be stopped at the interface between the planarization layer 310 and the substrate 210 during the thinning process, so as to ensure that the planarization layer 310 fully fills the groove structure 212, and the groove structure 212 filling the planarization layer 310 is flush or approximately flush with the first surface 211.
S140, preparing a suspension film on the first surface and the surface of the planarization layer, and preparing a window in the suspension film, wherein the vertical projection of the window on the plane of the substrate at least partially overlaps with the groove structure.
As shown in fig. 5 and 6, a suspension film 410 is prepared on the first surface 211 and the surface of the planarization layer 310, and a window 411 is prepared in the suspension film 410. Optionally, the suspended film 410 may be a thin film made of different materials, and the specific material of the suspended film 410 is not limited in the embodiment of the present invention. The window 411 may be formed by photolithography and etching processes, and the suspended film 410 is patterned to form the window 411. It should be noted that the vertical projection of the window 411 on the plane of the substrate 210 needs to at least partially overlap the recess structure 212, and at least a portion of the planarization layer 310 in the recess structure 212 can be exposed through the window 411, so as to facilitate the subsequent removal of the planarization layer 310 in the recess structure 212.
And S150, removing the planarization layer in the groove structure through the window to obtain the cavity structure.
As shown in fig. 7, the planarization layer 310 in the groove structure 212 is removed through the window 411, so that the cavity structure and the floating film 410 located above the cavity structure are obtained, and the surface of the floating film 410 is flat. Alternatively, the middle planarization layer 310 may be removed by using an organic solvent acetone or other chemical reagents that can dissolve the planarization layer, or the planarization layer 310 may be removed by using the characteristic of oxygen plasma isotropic etching, and the method for removing the planarization layer 310 is not limited in the embodiment of the present invention.
In summary, in the preparation method of the cavity structure provided by the embodiment of the invention, the substrate with the groove structure is covered with the plurality of flat layers, and then the substrate is thinned until the substrate is exposed, so that the flat layers completely fill the groove structure, and the purpose of planarization is achieved; and then preparing a suspended membrane, and removing the flat layer filled in the groove structure to obtain the cavity structure. The preparation method of the cavity structure provided by the embodiment of the invention can solve the problem of pattern planarization, and has the advantages of low difficulty of the preparation process of the cavity structure, low preparation cost and high practical feasibility.
On the basis of the above embodiment, preparing at least two planarization layers on the first surface side may include:
preparing at least two planarization layers on one side of the first surface according to the depth-to-width ratio and the flatness requirement of the groove structure; the planarization layer on one side of the first surface has a first height h1, and the planarization layer on one side of the groove structure has a second height h2, wherein | h1-h2|/h1 is less than or equal to 10%.
For example, when the planarization layer is prepared on the first surface side, the number of the film layers of the planarization layer may be determined according to the aspect ratio of the groove structure and the flatness requirement. When the depth-to-width ratio of the groove structure is larger and/or the flatness requirement is higher, a plurality of layers of planarization layers can be prepared, namely the preparation process of the planarization layers is repeated for a plurality of times, along with the increase of the number of times of repetition, the filling effect of the planarization layers on the groove structure is better, and the surface flatness of the whole device is higher. It can be understood that, when the number of the film layers of the planarization layer is larger, the operation of subsequently removing the planarization layer on the first surface side may be more complicated, so that in actual manufacturing of the planarization layer, the depth-to-width ratio and the flatness requirement of the groove structure and the operation process of subsequently removing the planarization layer may be comprehensively considered, the number of the film layers of the planarization layer is reasonably selected, and the depth-to-width ratio and the flatness requirement of the groove structure and the operation process of subsequently removing the planarization layer are ensured to be considered.
Further, the specific preparation process of the planarization layer may also be selected according to the difference of the aspect ratio of the groove structure, for example, a spin coating or spray coating process may be selected, or other processes may also be selected, and the method is not limited. When the preparation process is selected according to the depth-to-width ratio of the groove structure, the flatness requirement of the device is also considered, and for the device with higher flatness requirement, the process with better smoothness is preferred.
Further, theoretically, the height of the planarization layer on the first surface side and the height of the planarization layer on the groove structure side may be the same, but considering the actual process and the requirement of the planarization degree, the planarization layer on the first surface side may be set to have the first height h1, and the planarization layer on the groove structure side may have the second height h2, where | h1-h2|/h1 is less than or equal to 10%, so that the requirements of the actual process and the planarization degree can be considered, and the planarization layer with good planarization degree can be obtained. Specifically, as shown in fig. 3, the first height h1 is the distance from the upper surface of the planarization layer 310 at the first surface 211 to the second surface 213, and the second height h2 is the distance from the upper surface of the planarization layer 310 at the groove structure 212 to the second surface 213, and ideally, h1 may be h2, but considering the actual process, therefore, | h1-h2|/h1 ≦ 10% may be selected as the standard for completing the preparation of the planarization layer 310, taking into account the actual process and the requirement of the planarization degree.
Optionally, the at least two planarization layers include a first planarization layer and a second planarization layer, and the step of preparing the at least two planarization layers on the first surface side may specifically include:
preparing a first planarization layer on one side of the first surface, wherein the first planarization layer covers the first surface and the groove structure;
curing the first planarization layer;
preparing a second planarization layer on the side, away from the second surface, of the first planarization layer, wherein the second planarization layer covers the first planarization layer;
and curing the second planarization layer.
Illustratively, the at least two planarization layers include at least a first planarization layer and a second planarization layer, and correspondingly, the preparing the at least two planarization layers includes first preparing the first planarization layer, the first planarization layer covering the first surface and the groove structure. Because the planarization layer is made of organic materials, the first planarization layer needs to be cured after the first planarization layer is prepared, so that the first planarization layer is stable in structure and cannot flow continuously. According to the liquid/solid conversion characteristics of the organic material, optionally, the organic material may be baked in an oven, generally at a temperature of 90-120 ℃ for a period of time, to volatilize and fully cure the organic solvent in the planarization layer. It should be noted that, because the characteristics of different materials of the planarization layer are different, the baking temperature and the baking time are not fixed, so as to improve the efficiency and save the energy consumption on the premise of meeting the curing requirement. Further, after the curing of the first planarizing layer is completed, a second planarizing layer is prepared, and then the second planarizing layer is cured. Optionally, the first planarizing layer and the second planarizing layer may be the same material or different materials, which is not limited in this embodiment of the present invention. When the first planarization layer and the second planarization layer are made of the same material, the preparation and curing of the planarization layer can adopt the same process, so that the preparation process of the planarization layer is simple; when the first planarization layer and the second planarization layer are made of different materials, preparation and curing can be performed according to the characteristics of the respective materials, the preparation and curing processes of the planarization layer are not limited, and the processes can meet the preparation requirements without specific processes.
Furthermore, the thickness d of the first planarization layer can meet the requirement that d is not less than 1 μm and not more than 2 μm, the thickness requirement can be only made on the first planarization layer, the thickness of the first planarization layer can be smaller, and therefore a thinner planarization layer is covered on the first surface and the surface of the groove structure, and the planarization layer material can be well attached to the first surface and the groove structure. For example, when the groove structure includes a corner, the first planarizing layer covering thinner may smooth the corner; if the first planarization layer is too thin (d is less than 1 μm), the groove structure still has obvious edges and corners, and gaps are likely to exist near the edges and corners when the second planarization layer is covered, so that the filling of the planarization layer in the groove structure is not facilitated, and the surface flatness is influenced; if the first planarizing layer is excessively thick (d > 2 μm), voids are likely to be present at the corners of the groove structure when the first surface is covered with the first planarizing layer, and therefore, it is preferable that the thickness d of the first planarizing layer satisfies 1 μm d 2 μm. Furthermore, the surface state of the substrate can be adjusted through the first thinner planarization layer, and then the planarization layer is continuously covered to improve the surface flatness, so that the good bonding effect between the subsequent planarization layer and the substrate is ensured. Furthermore, the planarization layer prepared after the first planarization layer can be increased in thickness properly, the number of repeated operations is reduced, and the efficiency is improved.
Optionally, after the curing the first planarization layer, the method may further include:
and carrying out hydrophilic treatment on the first planarization layer.
For example, the solvent is volatilized during the curing process of the organic material, so that the hydrophilicity of the material is reduced, the hydrophobicity of the material is increased, the hydrophilic treatment on the first planarization layer is beneficial to being tightly combined with the first planarization layer when the second planarization layer is prepared, and the good combination of the first planarization layer and the second planarization layer is ensured.
Further, the hydrophilic treatment of the first planarizing layer may include:
carrying out hydrophilic treatment on the first planarization layer at a first preset temperature; the first preset temperature is lower than the curing temperature of the first planarization layer.
Optionally, the hydrophilic treatment can be performed at a lower power and a lower temperature by adopting plasma treatment equipment, and the lower power can avoid unnecessary energy consumption waste, effectively save energy and reduce process cost; the use of lower temperatures may avoid higher temperatures affecting the properties of the planarization layer. In addition, the method can set shorter operation time, shorten the process treatment time and improve the working efficiency. For example, the surface of the first planarizing layer may be treated with oxygen plasma at a first predetermined temperature for 10s-60s to increase the hydrophilicity of the surface of the first planarizing layer. Further, the hydrophilic treatment may be performed not only after the first planarizing layer is cured but before the second planarizing layer is prepared, and depending on the number of film layers of the planarizing layer, the hydrophilic treatment may be performed on the previously prepared planarizing layer before each planarizing layer is prepared.
Optionally, thinning the planarization layer to expose the first surface may specifically include:
thinning the planarization layer by adopting dry chemical vapor etching at a second preset temperature to expose the first surface; the second preset temperature is lower than the curing temperature of the planarization layer.
Illustratively, dry chemical vapor etching has better anisotropy than wet etching, and can perform single-sided etching on a certain surface very well, and a common dry chemical vapor etching method can adopt plasma etching. Optionally, the planarization layer thinning operation may be performed by selecting vertical bombardment of oxygen plasma on a dry etching machine, and in order to increase the thinning rate of the planarization layer, the second preset temperature may be appropriately increased, but the second preset temperature must be lower than the curing temperature of the planarization layer, so as to ensure that the material characteristics of the planarization layer are not damaged. Optionally, the whole thinning is performed by using an oxygen plasma vertical bombardment method until the first surface is exposed, and the operation is stopped after the edge anchor point of the first surface is exposed, as shown in fig. 4.
Optionally, preparing the suspended film on the first surface and the surface of the planarization layer may specifically include:
preparing suspended films on the first surface and the surface of the planarization layer at a third preset temperature by adopting physical vapor deposition; the third preset temperature is less than the curing temperature of the planarization layer.
For example, if the temperature is too high, which may destroy the material properties of the planarization layer and easily cause the shape expansion change, the suspended film is preferably prepared by a low temperature physical vapor deposition process, and the temperature may be room temperature.
In summary, the cavity structure prepared by the cavity structure preparation method provided by the embodiment of the invention is composed of the substrate and the suspended film, and compared with the cavity structure prepared by deep silicon etching in the prior art, the cavity structure is simpler in preparation process and lower in cost; the cavity preparation method provided by the embodiment of the invention is a process method for preparing a plurality of planarization layers and solidifying and reflowing, the dry chemical vapor etching is utilized to carry out surface integral thinning operation to planarize the surface, then the physical vapor deposition is adopted to prepare the suspended film, and the cavity structure can be obtained by removing the planarization layer, so that the cavity preparation method is compatible with a plurality of sensor process manufacturing processes, has universality, and can reduce energy consumption in the preparation process and improve efficiency by setting power, preset temperature and/or operation time.
Based on the same inventive concept, an embodiment of the present invention further provides a mems sensor, where the mems sensor at least includes a substrate, a cavity structure located in the substrate, and a suspended film located on a side of the cavity structure away from the substrate, where the cavity structure may be prepared by the method for preparing the cavity structure described in the above embodiment, and has a technical effect corresponding to the method for preparing the cavity structure in the above embodiment, and reference may be made to the description of the above embodiment specifically, and details are not repeated here.
Optionally, the mems sensor may include at least one of a mems pressure sensor, an infrared thermopile sensor, a mems acceleration sensor, a mems micromirror sensor, and a mems gyroscope sensor. The specific type of the mems sensor is not limited in the embodiments of the present invention, and the mems sensor in which a cavity structure needs to be formed in the sensor all belong to the protection scope of the embodiments of the present invention.
It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that the present invention is not limited to the specific embodiments described herein, and that the features of the various embodiments of the invention may be partially or fully coupled to each other or combined and may be capable of cooperating with each other in various ways and of being technically driven. Numerous variations, rearrangements, combinations, and substitutions will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.
Claims (10)
1. A method for preparing a cavity structure, comprising:
providing a substrate, wherein the substrate comprises a first surface and a second surface which are oppositely arranged, and the first surface is provided with a groove structure;
preparing at least two planarization layers on one side of the first surface, wherein the planarization layers cover the first surface and the groove structures; the planarization layer comprises an organic material layer, and the thickness of the planarization layer on one side of the first surface is smaller than that of the planarization layer on one side of the groove structure;
thinning the planarization layer to expose the first surface, wherein the planarization layer fills the groove structure;
preparing a suspension film on the first surface and the surface of the planarization layer, and preparing a window in the suspension film, wherein a vertical projection of the window on the plane of the substrate at least partially overlaps with the groove structure;
and removing the planarization layer in the groove structure through the window to obtain a cavity structure.
2. The method of manufacturing according to claim 1, wherein manufacturing at least two planarization layers on the first surface side includes:
preparing at least two planarization layers on one side of the first surface according to the depth-to-width ratio and the flatness requirement of the groove structure;
the planarization layer on one side of the first surface is provided with a first height h1, and the planarization layer on one side of the groove structure is provided with a second height h2, wherein | h1-h2|/h1 is less than or equal to 10%.
3. The production method according to claim 1, wherein the at least two planarization layers include a first planarization layer and a second planarization layer;
preparing at least two planarization layers on one side of the first surface, including:
preparing a first planarization layer on one side of the first surface, wherein the first planarization layer covers the first surface and the groove structure;
curing the first planarizing layer;
preparing a second planarization layer on the side of the first planarization layer away from the substrate, wherein the second planarization layer covers the first planarization layer;
and curing the second planarization layer.
4. The production method according to claim 3, wherein a thickness d of the first planarizing layer satisfies 1 μm. ltoreq. d.ltoreq.2 μm.
5. The method according to claim 3, further comprising, after curing the first planarizing layer:
and carrying out hydrophilic treatment on the first planarization layer.
6. The production method according to claim 5, wherein the hydrophilic treatment of the first planarizing layer includes:
carrying out hydrophilic treatment on the first planarization layer by adopting a first preset temperature; the first preset temperature is lower than the curing temperature of the first planarization layer.
7. The method of manufacturing of claim 1, wherein thinning the planarization layer to expose the first surface comprises:
thinning the planarization layer by adopting dry chemical vapor etching at a second preset temperature to expose the first surface; the second preset temperature is less than the curing temperature of the planarization layer.
8. The method of claim 1, wherein preparing the suspended film on the first surface and the planarization layer surface comprises:
preparing suspended films on the first surface and the surface of the planarization layer at a third preset temperature by adopting physical vapor deposition; the third preset temperature is less than the curing temperature of the planarization layer.
9. A micro electro mechanical system sensor is characterized by comprising a substrate, a cavity structure positioned in the substrate and a suspended film positioned on one side of the cavity structure, which is far away from the substrate;
the cavity structure is prepared by the preparation method of any one of claims 1 to 8.
10. The mems sensor of claim 9, wherein the mems sensor comprises at least one of a mems pressure sensor, an infrared thermopile sensor, a mems acceleration sensor, a mems micromirror sensor, and a mems gyroscope sensor.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113666328A (en) * | 2021-08-31 | 2021-11-19 | 苏州敏芯微电子技术股份有限公司 | Sensor structure, preparation method thereof and electronic equipment |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0897213A (en) * | 1994-09-29 | 1996-04-12 | Sony Corp | Manufacture of semiconductor device |
| TW428244B (en) * | 1996-04-15 | 2001-04-01 | United Microelectronics Corp | Planarization method for self-aligned contact process |
| KR20050069653A (en) * | 2003-12-31 | 2005-07-05 | 동부아남반도체 주식회사 | Method for fabricating inter metal dielectric of semiconductor device |
| US20090170287A1 (en) * | 2007-12-28 | 2009-07-02 | Semiconductor Energy Laboratory Co., Ltd. | Method for manufacturing soi substrate |
| CN101504930A (en) * | 2008-02-06 | 2009-08-12 | 株式会社半导体能源研究所 | Manufacturing method of SOI substrate |
| CN102375332A (en) * | 2010-08-19 | 2012-03-14 | 中国科学院上海微系统与信息技术研究所 | Suspension photoresist planarization technology for MEMS structure |
| CN103618044A (en) * | 2013-11-29 | 2014-03-05 | 上海集成电路研发中心有限公司 | Method for manufacturing piezoelectric cantilever beam sensor structure |
| CN105514258A (en) * | 2015-12-10 | 2016-04-20 | 上海集成电路研发中心有限公司 | Piezoelectric cantilever beam sensor structure and manufacturing method thereof |
-
2021
- 2021-04-14 CN CN202110400939.7A patent/CN113120855A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0897213A (en) * | 1994-09-29 | 1996-04-12 | Sony Corp | Manufacture of semiconductor device |
| TW428244B (en) * | 1996-04-15 | 2001-04-01 | United Microelectronics Corp | Planarization method for self-aligned contact process |
| KR20050069653A (en) * | 2003-12-31 | 2005-07-05 | 동부아남반도체 주식회사 | Method for fabricating inter metal dielectric of semiconductor device |
| US20090170287A1 (en) * | 2007-12-28 | 2009-07-02 | Semiconductor Energy Laboratory Co., Ltd. | Method for manufacturing soi substrate |
| CN101504930A (en) * | 2008-02-06 | 2009-08-12 | 株式会社半导体能源研究所 | Manufacturing method of SOI substrate |
| CN102375332A (en) * | 2010-08-19 | 2012-03-14 | 中国科学院上海微系统与信息技术研究所 | Suspension photoresist planarization technology for MEMS structure |
| CN103618044A (en) * | 2013-11-29 | 2014-03-05 | 上海集成电路研发中心有限公司 | Method for manufacturing piezoelectric cantilever beam sensor structure |
| CN105514258A (en) * | 2015-12-10 | 2016-04-20 | 上海集成电路研发中心有限公司 | Piezoelectric cantilever beam sensor structure and manufacturing method thereof |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113666328A (en) * | 2021-08-31 | 2021-11-19 | 苏州敏芯微电子技术股份有限公司 | Sensor structure, preparation method thereof and electronic equipment |
| CN113666328B (en) * | 2021-08-31 | 2024-05-14 | 苏州敏芯微电子技术股份有限公司 | Sensor structure, preparation method thereof and electronic equipment |
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