Micro-electro-mechanical system structure and manufacturing method thereof
By shortening the etching time of the sensing layer and designing the residual sensing layer, the problems of unevenness and leakage of the three-dimensional sensing structure in the micro-electromechanical system structure are solved, and higher sensing accuracy and reliability are achieved.
Patent Information
- Application Number
- CN202410246339.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-05
- Publication Date
- 2025-09-05
AI Technical Summary
During the manufacturing process of existing MEMS structures, the etching time of the sensing layer is too long, resulting in an uneven three-dimensional sensing structure, which is prone to micro-groove effects and leakage problems.
By shortening the etching time of the sensing layer, a portion of the sensing layer remains to form a three-dimensional structure. The first part of the patterned sensing layer is raised, and the second part has the same pattern as the circuit layer. An adhesive layer is used to improve the bonding properties, and the dielectric layer and insulating layer are processed to avoid leakage and micro-groove effects.
The uniformity of the three-dimensional sensing structure is improved, the micro-groove effect and leakage problems are avoided, and the sensing accuracy and reliability are improved.
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Figure CN120589673A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure provides a micro-electromechanical system (MEMS) structure and a method for manufacturing the MEMS structure. Background Art
[0002] Microelectromechanical systems (MEMS) are a technology that integrates miniaturized mechanical and electromechanical components on an integrated chip. MEMS devices are typically manufactured using micro-fabrication technology. In recent years, MEMS devices have gained widespread application. For example, MEMS devices are found in mobile phones (e.g., accelerometers, gyroscopes, digital compasses), pressure sensors, microfluidic components (e.g., valves, pumps), optical switches (e.g., (reflective) mirrors), imaging devices (e.g., micromachined ultrasonic transducers (MUTs)), biosensors (e.g., MEMS-based glucose sensors), and more. Summary of the Invention
[0003] In one aspect, the present disclosure provides a micro-electromechanical system (MEMS) structure comprising a substrate, an oxide layer, a circuit layer, and a patterned sensing layer. The oxide layer is disposed on the substrate. The circuit layer is disposed above the oxide layer. The patterned sensing layer is disposed on the circuit layer, wherein the patterned sensing layer comprises a first portion and a second portion, wherein the first portion is disposed on the second portion, and the pattern of the second portion is different from the pattern of the first portion.
[0004] According to one or more embodiments of the present disclosure, the patterned sensing layer includes titanium nitride.
[0005] According to one or more embodiments of the present disclosure, the patterned sensing layer includes a plurality of first portions spaced apart from each other and protruding upward from a second portion.
[0006] According to one or more embodiments of the present disclosure, the pattern of the second portion is the same as the pattern of the circuit layer.
[0007] According to one or more embodiments of the present disclosure, the MEMS structure further includes an adhesive layer disposed between the oxide layer and the circuit layer.
[0008] Another aspect of the present disclosure provides a method for fabricating a microelectromechanical system (MEMS) structure, comprising the following steps: forming an oxide layer overlying a substrate; forming a conductive layer overlying the oxide layer; forming a sensing layer overlying the conductive layer, wherein the sensing layer comprises a second portion and a first portion located over the second portion; patterning the first portion of the sensing layer to form a first patterned sensing layer; and patterning the second portion of the sensing layer and the conductive layer to form a second patterned sensing layer and a circuit layer, wherein the pattern of the second patterned sensing layer is different from the pattern of the first patterned sensing layer.
[0009] According to one or more embodiments of the present disclosure, the conductive layer or the circuit layer includes a copper-aluminum alloy.
[0010] According to one or more embodiments of the present disclosure, the method for manufacturing a MEMS structure further includes forming an adhesion layer between the oxide layer and the conductive layer.
[0011] According to one or more embodiments of the present disclosure, the second portion of the second patterned sensing layer has the same pattern as that of the circuit layer.
[0012] According to one or more embodiments of the present disclosure, the method for manufacturing a MEMS structure further includes forming a dielectric layer covering the second patterned sensing layer and the circuit layer; forming an insulating layer on the dielectric layer; and etching the insulating layer and the dielectric layer until the three-dimensional sensing portion of the second patterned sensing layer is exposed. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Various aspects of the present disclosure will be more fully understood from the following detailed description when read in conjunction with the accompanying drawings. It is noted that, in accordance with standard industry practice, various features are not drawn to scale. In fact, the dimensions of various features may be arbitrarily increased or decreased for clarity of discussion.
[0014] Figure 1 FIG. 1 is a schematic cross-sectional view of a micro-electromechanical system structure according to an embodiment of the present disclosure.
[0015] Figures 2 to 7 Schematic cross-sectional views of various process stages of manufacturing a MEMS structure according to one embodiment of the present disclosure. DETAILED DESCRIPTION
[0016] The following drawings illustrate various embodiments of the present disclosure. For clarity, many practical details are included in the following description. However, it should be understood that these practical details are not intended to limit the present disclosure. In other words, these practical details are not essential to some embodiments of the present disclosure. Furthermore, to simplify the drawings, some conventional structures and components are depicted in simplified schematic form.
[0017] To facilitate describing the relationship of one element or feature to another element or feature in the drawings, spatially relative terms such as "below," "beneath," "lower," "above," "above," "upper," and the like may be used. Spatially relative terms encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings. When the device is oriented in a different orientation (e.g., rotated 90 degrees or otherwise), the spatially relative adjectives used therein should be interpreted based on that orientation.
[0018] One aspect of the present disclosure provides a micro-electromechanical system (MEMS) structure that can be applied to biosensing. Figure 1 A cross-sectional schematic diagram of a MEMS structure 10 according to an embodiment of the present disclosure is shown. The MEMS structure 10 includes a substrate 100, an oxide layer 110, a circuit layer 120, and a patterned sensing layer 130. Specifically, the oxide layer 110 is disposed on the substrate 100. In some embodiments, the substrate 100 may include a semiconductor material, such as single crystal silicon, polycrystalline silicon, amorphous silicon, SiGe, Ge, SiC, etc. In some embodiments, the oxide layer 110 includes a nitride (e.g., silicon nitride (SiN)), an oxide (e.g., silicon dioxide (SiO2)), an oxynitride (e.g., silicon oxynitride (SiO X N Y )), other dielectric materials or combinations of the foregoing.
[0019] Continue reading Figure 1 The circuit layer 120 is disposed above the oxide layer 110. In some embodiments, the circuit layer 120 includes aluminum-copper alloy (AlCu) or other suitable conductive materials.
[0020] In some embodiments, the MEMS structure 10 may further include an adhesion layer 160 disposed between the oxide layer 110 and the circuit layer 120. In some embodiments, the adhesion layer 160 includes titanium, such as a titanium layer, which can improve the bonding between the circuit layer 120 and the oxide layer 110.
[0021] Continue reading Figure 1, the patterned sensing layer 130 is disposed on the circuit layer 120. It is noteworthy that the pattern of the patterned sensing layer 130 is different from the pattern of the circuit layer 120. In some embodiments, the patterned sensing layer 130 includes a metal nitride, such as titanium nitride (TiN) or other suitable sensing materials. In some embodiments, the patterned sensing layer 130 includes a first portion 130a and a second portion 130b, wherein the first portion 130a is disposed on the second portion 130b, and the pattern of the second portion 130b is different from the pattern of the first portion 130a. In some embodiments, the pattern of the second portion 130b of the patterned sensing layer 130 is the same as the pattern of the circuit layer 120. In some embodiments, a plurality of first portions 130a protrude upward from the second portion 130b, and the first portions 130a are spaced apart from each other by a specific distance. In some embodiments, the distance between two adjacent first portions 130a can be approximately 1.0 micron to 2.0 microns, for example, approximately 1.1 microns, 1.2 microns, 1.3 microns, 1.4 microns, 1.5 microns, 1.6 microns, 1.7 microns, 1.8 microns, or 1.9 microns. In some embodiments, the width of each first portion 130a can be approximately 0.3 micron to 0.8 micron, for example, approximately 0.4 micron, 0.5 micron, 0.6 micron, or 0.7 micron. In some embodiments, the height of the first portion 130a is greater than the height of the second portion 130b. In some embodiments, multiple first portions 130a are connected to each other through multiple second portions 130b.
[0022] Another aspect of the present disclosure provides a method for fabricating a MEMS structure. Figures 2 to 7 1 is a schematic cross-sectional view of various process stages of manufacturing a MEMS structure 10 according to one embodiment of the present disclosure. The method of manufacturing the MEMS structure 10 includes the following steps.
[0023] First, an oxide layer 110 is formed to cover the substrate 100, as shown in FIG. Figure 2In some embodiments, the oxide layer 110 can be formed on the substrate 100 by plasma-enhanced chemical vapor deposition (PECVD), sub-atmospheric chemical vapor deposition (SACVD), atmospheric pressure chemical vapor deposition (APCVD), high-density plasma chemical vapor deposition (HDPCVD), physical vapor deposition (PVD), atomic layer deposition (ALD), thermal oxidation, or other suitable methods. In some embodiments, the thickness of the oxide layer 110 is about to For example, it can be about or
[0024] Next, a conductive layer 122 is formed to cover the oxide layer 110, as shown in FIG. Figure 2 In some embodiments, the conductive layer 122 may be formed on the oxide layer 110 by PVD, chemical vapor deposition (CVD), electrolytic plating, electroless plating, or other suitable methods. In some embodiments, the conductive layer 122 comprises aluminum-copper alloy (AlCu) or other suitable conductive materials. In some embodiments, the thickness of the conductive layer 122 is about to For example, it can be about or
[0025] In some embodiments, an adhesion layer 162 may be formed between the conductive layer 122 and the oxide layer 110, such as Figure 2 As shown. In some embodiments, the adhesion layer 162 can be first formed on the oxide layer 110 using PVD, CVD, electrolytic plating, electroless plating or other suitable methods, and then the conductive layer 122 can be formed on the adhesion layer 162. In some embodiments, the adhesion layer 160 includes titanium, such as a titanium layer. The titanium layer can increase the bonding between the circuit layer 120 and the oxide layer 110. In some embodiments, the thickness of the adhesion layer 162 is about to For example, it can be about or
[0026] Next, the sensing layer 132 is formed to cover the conductive layer 122, as shown in FIG. Figure 2 In some embodiments, the sensing layer 132 may be formed on the conductive layer 122 using PVD, sputtering, CVD, PECVD, APCVD, low-pressure chemical vapor deposition (LPCVD), HDPCVD, or ALD. In some embodiments, the patterned sensing layer 132 includes a metal nitride, such as titanium nitride (TiN) or other suitable sensing materials. In some embodiments, the thickness of the sensing layer 132 is about to For example, it can be about or
[0027] The first portion 132a of the patterned sensing layer 132 is formed to form the first patterned sensing layer 132. Specifically, the first portion 132a of the patterned sensing layer 132 can be formed by first forming a photoresist PR1 on the sensing layer 132, such as Figure 2 Next, the sensing layer 132 is etched and the photoresist PR1 is removed, as shown in FIG. Figure 3 As shown. In some embodiments, a dry etching process can be used to pattern the first portion 132a of the sensing layer 132. For example, a dry etching gas including chlorine (Cl2) can be used for etching. It is worth noting that when etching the sensing layer 132, the etching time is shortened so that a portion of the sensing layer 132 not covered by the photoresist PR1 can remain (i.e., the second portion 132b). In other words, the sensing layer 132 not covered by the photoresist PR1 is not completely etched. Therefore, the patterned sensing layer 132 includes the second portion 132b and the protruding first portion 132a, and the thickness of the first portion 132a is greater than the thickness of the second portion 132b. In some embodiments, the thickness of the second portion 132b can be about to For example, it can be about or
[0028] It is understood that the first portion 132a of the sensing layer 132 has a three-dimensional structure to increase the contact area with the reactants. Therefore, better uniformity of the first portion 132a of the sensing layer 132 can improve sensing accuracy. In this embodiment, shortening the etching time of the sensing layer 132 can effectively improve the three-dimensional uniformity of the first portion 132a of the sensing layer 132 in the central and edge regions.
[0029] It is worth noting that the remaining sensing layer 132, i.e., the second portion 132b of the sensing layer 132, can prevent the subsequent etching of the conductive layer 122 below from over-etching and forming an etching depth with sharp corners when the circuit layer is subsequently etched, thereby generating a micro-trench effect. In addition, the remaining sensing layer 132, i.e., the second portion 132b of the sensing layer 132, can also help in the subsequent etching of the insulating layer 152 and the dielectric layer 142 (shown in FIG. Figure 7 ) when the circuit layer is not easily exposed and causes leakage defects.
[0030] Next, the second portion 132b of the sensing layer 132 and the conductive layer 122 are patterned to form the second patterned sensing layer 130 and the circuit layer 120. Specifically, the second portion 132b of the patterned sensing layer 132 and the conductive layer 122 can be patterned by first forming a photoresist PR2 on the sensing layer 132, such as Figure 4 At this point, the three-dimensional structure for sensing (i.e., the first portion 132a of the sensing layer 132) will be covered by the photoresist PR2 and will not be affected by subsequent etching. Next, the second portion 132b of the sensing layer 132, the conductive layer 122, and the adhesive layer 162 are etched, and the photoresist PR2 is removed to form the following structure: Figure 5 The second patterned sensing layer 130 and the circuit layer 120 are shown. In some embodiments, a dry etching process can be used to form the second patterned sensing layer 130 and the circuit layer 120. For example, a dry etching gas including chlorine (Cl2) can be used for etching. It is understood that the second patterned sensing layer 130 includes a second portion 130b and a protruding first portion 130a, and the pattern of the second portion 130b is different from the pattern of the first portion 130a. The pattern of the second portion 130b of the second patterned sensing layer 130 is the same as the pattern of the circuit layer 120.
[0031] Then, a dielectric layer 142 is formed to cover the second patterned sensing layer 130 and the circuit layer 120. Figure 6 More specifically, dielectric layer 142 conformally and continuously covers a portion of the surface of oxide layer 110, the sidewalls of adhesion layer 160, the sidewalls of circuit layer 120, and the surface of second patterned sensing layer 130. In some embodiments, dielectric layer 142 includes plasma-enhanced oxide (PEOX) or other similar dielectric materials.
[0032] An insulating layer 152 is formed on the dielectric layer 142, such as Figure 7In some embodiments, the insulating layer 152 may include silicon dioxide, a low-k material (a material having a lower dielectric constant than silicon dioxide), such as silicon oxynitride, phosphosilicate glass (PSG), borophosphosilicate glass (BPSG), fluorinated silicate glass (FSG), organosilicate glass (OSG), carbon-doped glass (SiO x C y ), spin-on-glass, spin-on-polymers, carbon silicide materials, compounds thereof, composites thereof, combinations thereof, or other suitable materials. These materials may be deposited using a suitable method, such as spin coating, chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), or other suitable methods to achieve planarization. It will be appreciated that the insulating layer 152 may fill the recess of the dielectric layer 142 such that the top surface of the insulating layer 152 is flush with the top surface of the dielectric layer 142.
[0033] The insulating layer 152 and the dielectric layer 142 are then etched until the three-dimensional sensing portion (ie, the first portion 130a) of the second patterned sensing layer 130 is exposed, so as to obtain Figure 1 The MEMS structure 10 is shown. In some embodiments, the second patterned sensing layer 130 and the circuit layer 120 (and / or the adhesive layer 160) are covered by the etched dielectric layer 140, exposing a portion of the first portion 130a of the second patterned sensing layer 130. In a top view, the etched insulating layer 150 surrounds the etched dielectric layer 140.
[0034] In summary, the present disclosure shortens the etching time of the sensing layer during the fabrication of a MEMS structure, thereby improving the uniformity of the three-dimensional sensing structure. Furthermore, shortening the etching time of the sensing layer to leave a portion of the sensing layer untouched not only prevents the micro-grooving effect but also avoids leakage issues caused by exposing the circuit layer during subsequent etching processes.
[0035] Although the present disclosure has been disclosed above in the form of embodiments, it is not intended to limit the present disclosure. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be determined by the appended claims.
[0036]
Explanation of symbols
[0037] 10: MEMS structure
[0038] 100:Substrate
[0039] 110: Oxide layer
[0040] 120: Circuit layer
[0041] 122: conductive layer
[0042] 130: Patterned sensing layer
[0043] 130a: Part 1
[0044] 130b: Part 2
[0045] 132: Sensing layer
[0046] 132a: Part 1
[0047] 132b: Part 2
[0048] 140: dielectric layer
[0049] 142: Dielectric layer
[0050] 150: Insulation layer
[0051] 152: Insulation layer
[0052] 160: Adhesive layer
[0053] 162: Adhesive layer
[0054] PR1: Photoresist
[0055] PR2: Photoresist.
Claims
1. A micro-electromechanical system structure, characterized in that: include: an oxide layer disposed on the substrate; a circuit layer, disposed above the oxide layer; as well as The patterned sensing layer is disposed on the circuit layer, wherein the patterned sensing layer includes a first portion and a second portion, the first portion is located on the second portion, and a pattern of the second portion is different from a pattern of the first portion. 2 . The MEMS structure according to claim 1 , wherein the patterned sensing layer comprises titanium nitride. 3 . The MEMS structure according to claim 1 , wherein the patterned sensing layer comprises a plurality of first portions protruding upward from the second portion at intervals. 4 . The MEMS structure according to claim 1 , wherein the pattern of the second portion is the same as a pattern of the circuit layer.
5. The MEMS structure according to claim 1, wherein: The invention also includes an adhesive layer arranged between the oxide layer and the circuit layer.
6. A method for manufacturing a micro-electromechanical system structure, characterized in that: include: forming an oxide layer to cover the substrate; forming a conductive layer covering the oxide layer; forming a sensing layer covering the conductive layer, wherein the sensing layer has a second portion and a first portion located on the second portion; patterning the first portion of the sensing layer to form a first patterned sensing layer; as well as The second portion of the sensing layer and the conductive layer are patterned to form a second patterned sensing layer and a circuit layer, wherein a pattern of the second patterned sensing layer is different from a pattern of the first patterned sensing layer. 7 . The method for manufacturing a micro-electromechanical system structure according to claim 6 , wherein the conductive layer or the circuit layer comprises a copper-aluminum alloy.
8. The method for manufacturing a micro-electromechanical system structure according to claim 6, wherein: The method also includes forming an adhesive layer between the oxide layer and the conductive layer. 9 . The method for manufacturing a MEMS structure according to claim 6 , wherein the second patterned sensing layer has the same pattern as that of the circuit layer.
10. The method for manufacturing a micro-electromechanical system structure according to claim 6, wherein: Also includes: forming a dielectric layer to cover the second patterned sensing layer and the circuit layer; forming an insulating layer on the dielectric layer; and The insulating layer and the dielectric layer are etched until the three-dimensional sensing portion of the second patterned sensing layer is exposed.