Method of manufacturing a semiconductor device and electronic device

Abstract

A method for manufacturing a semiconductor device and an electronic device, the manufacturing method comprising: forming a MEMS device and a first sacrificial layer, the MEMS device comprising a fixed structure, the fixed structure comprising a substrate and a surrounding wall structure surrounding the substrate, the MEMS device further comprising a movable structure suspended above the substrate, and a second sacrificial layer located between the movable structure and the fixed structure, the first sacrificial layer being used to support the separation of the movable structure from the fixed structure, and the process of removing the second sacrificial layer having a greater removal rate for the second sacrificial layer than for the first sacrificial layer; removing the second sacrificial layer; and after removing the second sacrificial layer, removing the first sacrificial layer. The present invention forms the first sacrificial layer, and during the process of removing the second sacrificial layer, the first sacrificial layer is used to support the separation of the movable structure from the fixed structure, thereby reducing the probability of surface bonding or adhesion between the movable structure and the fixed structure, thereby improving process reliability and correspondingly improving the performance of the semiconductor device.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of semiconductor manufacturing, and in particular to a method for manufacturing a semiconductor device and an electronic device. Background Art

[0002] Micro-Electro-Mechanical Systems (MEMS) is an industrial technology that integrates microelectronics and mechanical engineering, operating within the micrometer range. MEMS is a completely new research and development field that must simultaneously consider the mixed effects of multiple physical fields. Compared to traditional machines, they are smaller in size, with the largest not exceeding one centimeter and even just a few microns, and their thickness is even smaller.

[0003] MEMS can be produced in large quantities and at low cost using mature integrated circuit technologies and processes, resulting in high-performance MEMS chips. With the development of ultra-large-scale integrated circuits, the requirements for integrated circuit manufacturing technology have also continued to increase. The packaging structure of the MEMS chip and other functional chips has opened up a new technological field and industry. By integrating the MEMS chip and other functional chips into a single unit, a system or subsystem that can provide multiple functions is formed. Micro-actuators, micro-sensors, micro-actuators, micro-components, micro-mechanical optical devices, vacuum microelectronic devices, power electronic devices, etc. manufactured based on this packaging structure have very broad application prospects in aviation, aerospace, automobiles, biomedicine, environmental monitoring, military, and almost all fields that people come into contact with. Summary of the Invention

[0004] The problem solved by the embodiments of the present invention is to provide a method for manufacturing a semiconductor device and an electronic device to improve the performance of the semiconductor device.

[0005] To solve the above problems, an embodiment of the present invention provides a method for manufacturing a semiconductor device, comprising: forming a MEMS device and a first sacrificial layer, the MEMS device comprising a fixed structure, the fixed structure comprising a substrate and a wall structure surrounding the substrate, the MEMS device further comprising a movable structure suspended on the substrate, and a second sacrificial layer located between the movable structure and the fixed structure, the first sacrificial layer being used to support the movable structure to be separated from the fixed structure, and a process for removing the second sacrificial layer having a greater removal rate for the second sacrificial layer than for the first sacrificial layer; after forming the MEMS device and the first sacrificial layer, removing the second sacrificial layer; and after removing the second sacrificial layer, removing the first sacrificial layer.

[0006] Correspondingly, an embodiment of the present invention further provides a semiconductor device formed by the method for manufacturing a semiconductor device according to the embodiment of the present invention.

[0007] Compared with the prior art, the technical solution of the embodiment of the present invention has the following advantages:

[0008] In the manufacturing method of the semiconductor device provided by an embodiment of the present invention, before removing the second sacrificial layer, a first sacrificial layer is first formed to support the separation of the movable structure from the fixed structure. Therefore, in the process of removing the second sacrificial layer, under the supporting effect of the first sacrificial layer, the probability of surface bonding or adhesion between the movable structure and the fixed structure (for example, the substrate) is reduced, and the process of removing the second sacrificial layer has a greater removal rate for the second sacrificial layer than the removal rate for the first sacrificial layer. Therefore, after removing the second sacrificial layer, the first sacrificial layer suffers less loss, so that the performance of the first sacrificial layer is guaranteed, thereby improving process reliability, which is correspondingly beneficial to improving the performance of the semiconductor device.

[0009] In an optional solution, the movable structure includes a mounting area, the first sacrificial layer exposes the mounting area, and after removing the second sacrificial layer and before removing the first sacrificial layer, the manufacturing method of the semiconductor device further includes: fixing the component to be mounted on the movable structure in the mounting area; by removing the second sacrificial layer before fixing the component to be mounted on the movable structure, this avoids the influence of the process of removing the second sacrificial layer on the component to be mounted, and the first sacrificial layer is used to support the separation of the movable structure from the fixed structure. Therefore, the first sacrificial layer has the function of fixing the movable structure, which accordingly enables the component to be mounted to be accurately fixed to the movable structure. On the movable structure, moreover, compared with the second sacrificial layer, the amount of the first sacrificial layer is smaller, the first sacrificial layer is easy to be removed, and the time required for removing the first sacrificial layer is shorter, therefore, the process of removing the first sacrificial layer has less impact on the components to be mounted; in summary, the embodiment of the present invention forms the first sacrificial layer and then removes the second sacrificial layer before fixing the components to be mounted on the movable structure, which can improve the alignment accuracy of the components to be mounted and the movable structure while reducing the probability of damage to the components to be mounted, thereby improving process reliability, and can use wafer-level manufacturing process to form the semiconductor device, the installation position of the components to be mounted has high accuracy, and the output of the manufacturing process is high.

[0010] In an optional solution, after removing the second sacrificial layer and before removing the first sacrificial layer, the manufacturing method of the semiconductor device further includes: forming an oxide layer on the surface of the fixed structure and the movable structure; the oxide layer is used as a passivation layer, even if the movable structure approaches or adheres to the substrate due to deformation, the oxide layer located on the bottom surface of the movable structure and the surface of the substrate will not react further, thereby further reducing the probability of adhesion between the movable structure and the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figures 1 to 3 It is a structural schematic diagram corresponding to each step in a method for manufacturing a semiconductor device;

[0012] Figures 4 to 8 1 is a schematic structural diagram corresponding to each step in an embodiment of a method for manufacturing a semiconductor device of the present invention;

[0013] Figure 9 1 is a schematic structural diagram of a MEMS device and a first sacrificial layer in another embodiment of a method for manufacturing a semiconductor device of the present invention;

[0014] Figures 10 and 11 It is a structural schematic diagram corresponding to each step in another embodiment of the method for manufacturing a semiconductor device of the present invention. DETAILED DESCRIPTION

[0015] Current microactuator fabrication processes are designed to produce minute translational displacements. However, the critical dimensions of each layer in the device are small, the wafer-level fabrication process is complex, and process reliability still needs to be improved. This article examines the reasons why process reliability still needs to be improved, using a semiconductor device manufacturing method.

[0016] Figures 1 to 3 The present invention is a structural schematic diagram corresponding to each step in a method for manufacturing a semiconductor device.

[0017] refer to Figure 1 , a MEMS device (not shown) is provided, which includes a substrate 10 and a surrounding wall structure 20 surrounding the substrate 10, a movable structure 30 is suspended on the substrate 10, and a sacrificial layer 40 is formed between the movable structure 30 and the substrate 10, and between the movable structure 30 and the surrounding wall structure 20.

[0018] refer to Figure 2 , a component 50 to be mounted is fixed on the movable structure 30 .

[0019] refer to Figure 3 After fixing the component 50 to be mounted on the movable structure 30, the sacrificial layer 40 (eg Figure 2 As shown), a cavity 60 surrounded by the base 10, the surrounding wall structure 20 and the movable structure 30 is formed.

[0020] The sacrificial layer 40 is formed during the process of manufacturing the MEMS device.

[0021] However, after the sacrificial layer 40 is removed, the movable structure 30 loses its support. Therefore, surface bonding or adhesion is likely to occur between the movable structure 30 and the substrate 10, thereby reducing process reliability and correspondingly reducing the performance of the semiconductor device.

[0022] For example, after the sacrificial layer 40 is removed by a wet etching process, the surface tension of the liquid can easily cause the surface of the movable structure 30 to adhere to the adjacent surface of the substrate 10. Alternatively, if the movable structure 30 is large, after the sacrificial layer 40 is removed, the movable structure 30 can easily undergo stress deformation, thereby moving closer to or even adhering to the adjacent surface of the substrate 10.

[0023] Moreover, after the surface of the movable structure 30 is in contact with the surface of the substrate 10 , the surface of the movable structure 30 may react with the material of the substrate 10 , thereby causing adhesion between the movable structure 30 and the substrate 10 .

[0024] In order to solve the technical problem, an embodiment of the present invention provides a method for manufacturing a semiconductor device, including: forming a MEMS device and a first sacrificial layer, the MEMS device including a fixed structure, the fixed structure including a substrate and a wall structure surrounding the substrate, the MEMS device also including a movable structure suspended on the substrate, and a second sacrificial layer located between the movable structure and the fixed structure, the first sacrificial layer being used to support the separation of the movable structure from the fixed structure, and the process of removing the second sacrificial layer having a greater removal rate for the second sacrificial layer than for the first sacrificial layer; after forming the MEMS device and the first sacrificial layer, removing the second sacrificial layer; after removing the second sacrificial layer, removing the first sacrificial layer.

[0025] In an embodiment of the present invention, before removing the second sacrificial layer, a first sacrificial layer is first formed to support the separation of the movable structure from the fixed structure. Therefore, in the process of removing the second sacrificial layer, under the supporting effect of the first sacrificial layer, the probability of surface bonding or adhesion between the movable structure and the fixed structure is reduced, and the process of removing the second sacrificial layer has a greater removal rate for the second sacrificial layer than the removal rate for the first sacrificial layer. Therefore, after removing the second sacrificial layer, the first sacrificial layer suffers less loss, so that the performance of the first sacrificial layer is guaranteed, thereby improving process reliability, which is correspondingly beneficial to improving the performance of semiconductor devices.

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0027] Figures 4 to 8 It is a schematic structural diagram corresponding to each step in an embodiment of a method for manufacturing a semiconductor device of the present invention.

[0028] Combined with reference Figure 4 and Figure 5 , forming a MEMS device 300 and a first sacrificial layer 140, the MEMS device 300 includes a fixed structure 70, the fixed structure 70 includes a substrate 100 and a wall structure 110 surrounding the substrate 100, the MEMS device 300 also includes a movable structure 120 suspended on the substrate 100, and a second sacrificial layer 115 located between the movable structure 120 and the fixed structure 70, the first sacrificial layer 140 is used to support the movable structure 120 to be separated from the fixed structure 70, and the process of removing the second sacrificial layer 115 has a greater removal rate for the second sacrificial layer 115 than the removal rate for the first sacrificial layer 140.

[0029] The forming method is used to realize the manufacture of a micro-actuator, thereby realizing translation of a micro-displacement by utilizing the formed semiconductor device.

[0030] Therefore, the component to be mounted is subsequently fixed to the MEMS device 300 .

[0031] In this embodiment, the MEMS device 300 is integrated into a MEMS wafer, which includes multiple MEMS chips, thereby achieving a wafer-level manufacturing process and improving the yield of the manufacturing process. In other embodiments, the MEMS device can also be a MEMS chip obtained by dicing the MEMS wafer.

[0032] In this embodiment, the base 100 includes a substrate. Specifically, the substrate is made of silicon. In other embodiments, the substrate may be made of other materials such as germanium, silicon germanium, silicon carbide, gallium arsenide, or indium gallium. The substrate may also be a silicon-on-insulator substrate, a germanium-on-insulator substrate, or other types of substrates.

[0033] The surrounding wall structure 110 is used to limit the movable range of the movable structure 120 in a direction parallel to the surface of the substrate 100. Therefore, the bottom surface of the movable structure 120 is lower than the top surface of the surrounding wall structure 110.

[0034] In this embodiment, the top surface of the movable structure 120 is flush with the top surface of the surrounding wall structure 110. In other embodiments, the top surface of the movable structure may be higher than the top surface of the surrounding wall structure, or the top surface of the movable structure may be lower than the top surface of the surrounding wall structure.

[0035] In this embodiment, the second sacrificial layer 115 is formed during the preparation of the MEMS device 300 , and the second sacrificial layer 115 surrounds the movable structure 120 .

[0036] The second sacrificial layer 115 is used to provide a process platform for the formation of the movable structure 120. Moreover, after the second sacrificial layer 115 is subsequently removed, the movable structure 120 can be suspended on the substrate 100, thereby forming a cavity surrounded by the substrate 100, the surrounding wall structure 110 and the movable structure 120 by releasing the second sacrificial layer 115.

[0037] As an example, the steps of forming the second sacrificial layer 115 and the movable structure 120 include: forming a first sub-sacrificial layer (not shown) on the substrate 100; forming the movable structure 120 on a portion of the first sub-sacrificial layer; and forming a second sub-sacrificial layer (not shown) on the first sub-sacrificial layer exposed from the movable structure 120, wherein the second sub-sacrificial layer covers the sidewalls of the movable structure 120, and the second sub-sacrificial layer and the first sub-sacrificial layer constitute the second sacrificial layer 115. Alternatively, the steps of forming the first sacrificial layer 115 and the movable structure 120 include: forming the second sacrificial layer 115 on the substrate 100; forming a groove (not shown) in the second sacrificial layer 115; and forming the movable structure 120 in the groove.

[0038] The second sacrificial layer 115 will be removed later. Therefore, the material of the second sacrificial layer 115 is easy to remove, and the process of removing the second sacrificial layer 115 causes less damage to the fixed structure 70 and the movable structure 120 .

[0039] Furthermore, the second sacrificial layer 115 is formed during the fabrication of the MEMS device 300 . Therefore, the material of the second sacrificial layer 115 is compatible with semiconductor processes.

[0040] In addition, a first sacrificial layer 140 is subsequently formed on the second sacrificial layer 115. Therefore, in the subsequent process of removing the second sacrificial layer 115, the material of the second sacrificial layer 115 must meet the following requirements: the removal rate of the second sacrificial layer 115 in the process of removing the second sacrificial layer 115 is greater than the removal rate of the first sacrificial layer 140, so that after the second sacrificial layer 115 is removed, the first sacrificial layer 140 can be retained, and the integrity of the first sacrificial layer 140 is better, so that the performance of the first sacrificial layer 140 is guaranteed.

[0041] Accordingly, when selecting the material of the second sacrificial layer 115, the material of the subsequently formed first sacrificial layer 140 must be considered. For example, when the second sacrificial layer 115 is subsequently removed, the ratio of the removal rate of the second sacrificial layer 115 to the first sacrificial layer 140 is greater than or equal to 10:1.

[0042] The material of the second sacrificial layer 115 may include silicon oxide, germanium, or carbon. Silicon oxide, germanium, or carbon is easily removable, and the side effects of the removal process are minimal. This helps reduce the impact of the process of removing the second sacrificial layer 115 on the fixed structure 70, the movable structure 120, and the first sacrificial layer 140. It also helps increase the flexibility of the material selection for the first sacrificial layer 140, facilitating the selection of a suitable material for the first sacrificial layer 140.

[0043] In this embodiment, the second sacrificial layer 115 is made of silicon oxide. Silicon oxide is relatively inexpensive and simplifies the process for forming the second sacrificial layer 115. For example, silicon oxide is easy to fill and planarize and has better process temperature adaptability.

[0044] In this embodiment, after the second sacrificial layer 115 is subsequently removed, the component to be mounted is secured to the movable structure 120. Therefore, compared to a solution in which the second sacrificial layer is removed after securing the component to be mounted, the material selection for the second sacrificial layer 115 is more flexible. In other words, when selecting the material for the second sacrificial layer 115, there is no need to consider whether the component to be mounted can withstand the release process and process conditions of the second sacrificial layer 115.

[0045] The movable structure 120 is used to support the components to be mounted. In this embodiment, during the operation of the semiconductor device being formed, the movable structure 120 can move, thereby driving the components to be mounted above it to move. For example, the movable structure 120 can translate in a direction parallel to the surface of the substrate 100.

[0046] For example, when the MEMS device 300 is applied to an imaging module and the component to be installed is an image sensor chip, the image sensor is moved by the movable structure 120 so that the image sensor compensates for the displacement of the imaging point, thereby achieving optical image stabilization and correspondingly improving the imaging quality.

[0047] In this embodiment, the movable structure 120 includes a mounting area 120a. The mounting area 120a is used to define the position of a component to be subsequently mounted on the movable structure 120. Specifically, the component to be mounted is subsequently fixed to the movable structure 120 within the mounting area 120a. Specifically, the movable structure 120 also includes a peripheral area (not shown) surrounding the mounting area 120a.

[0048] It should be noted that if Figure 4 As shown in FIG. 1 , the smaller the distance d1 between the movable element 120 and the substrate 100 in a direction perpendicular to the surface of the substrate 100, the more stable support the movable element 120 can obtain in the longitudinal direction. The longitudinal direction refers to the direction perpendicular to the surface of the substrate 100, and the distance d1 between the movable element 120 and the substrate 100 refers to the distance from the bottom surface of the movable element 120 to the top surface of the substrate 100.

[0049] Therefore, the distance d1 between the movable element 120 and the substrate 100 should not be too large. If the distance d1 between the movable element 120 and the substrate 100 is too large, it will be difficult for the movable element 120 to obtain sufficient support in the longitudinal direction after the second sacrificial layer 115 is subsequently removed, which may easily cause the movable element 120 to deform in the longitudinal direction, thereby increasing the probability of adhesion or sticking between the movable element 120 and the substrate 100, or easily increase the difficulty of subsequently fixing the component to be mounted on the movable element 120. In addition, the longitudinal downward force generated during the installation of the component to be mounted, if the distance d1 between the movable element 120 and the substrate 100 is too large, it is also easy to cause the movable element 120 to deform in the longitudinal direction and also easily cause the first sacrificial layer 140 to break.

[0050] Therefore, in this embodiment, the distance d1 between the movable element 120 and the substrate 100 is greater than 0 and less than or equal to 5 micrometers.

[0051] It should also be noted that in the direction parallel to the surface of the substrate 100, the distance d2 between the movable element 120 and the surrounding wall structure 110 is a first distance, and in the direction perpendicular to the surface of the substrate 100, the distance d1 from the movable element 120 to the substrate 100 is a second distance, and the first distance is greater than the second distance.

[0052] The ratio of the first spacing to the second spacing should not be too small. If the ratio is too small, the closer the spacing d2 between the movable element 120 and the surrounding wall structure 110 is to the spacing d1 between the movable element 120 and the base 100, the more likely it is that the first sacrificial layer 140 will deform excessively when the movable element 120 moves closer to the base 100, thereby increasing the probability of fracture in the first sacrificial layer 140. For example, during the installation of the component to be installed, a longitudinal downward pressure may be generated, causing the movable element 120 to move closer to the base 100.

[0053] To this end, in this embodiment, the first spacing is greater than or equal to 10 times the second spacing. As an example, when the spacing d1 between the movable structure 120 and the substrate 100 is less than or equal to 5 microns, the spacing d2 between the movable structure 120 and the surrounding wall structure 110 is greater than or equal to 100 microns. The spacing d2 between the movable structure 120 and the surrounding wall structure 110 refers to the spacing between the opposing sidewalls of the movable structure 120 and the surrounding wall structure 110.

[0054] In this embodiment, in the step of forming the MEMS device 300, a first connection end (not shown) is formed in the surrounding wall structure 110, and the first connection end is exposed on the top surface of the surrounding wall structure 110, and a second connection end (not shown) is formed in the movable structure 120, and the second connection end is exposed on the top surface of the movable structure 120.

[0055] The first connection end is used to electrically connect the wall structure 110 to other components or structures, and the second connection end is used to electrically connect the movable structure 120 to other components or structures. For example, either the first connection end or the second connection end is used to power the components to be installed or to drive the movable structure 120 to move.

[0056] As an example, after the component to be mounted is fixed on the movable structure 120, a wire bonding process can be used, and the first connection end and the second connection end can be used to achieve electrical connection between the component to be mounted, the movable structure and the fixed structure 70, thereby driving the operation of the semiconductor device.

[0057] Specifically, the first connection end may be a pin or a pad. Similarly, the second connection end may be a pin or a pad.

[0058] As an example, the second connection end is located in the peripheral area of the movable element 120. After the component to be mounted is subsequently fixed to the movable structure in the mounting area, the second connection end of the component to be mounted is exposed, thereby enabling the movable structure 120 to be electrically connected to other components or structures through the second connection end.

[0059] In this embodiment, a first release hole 121 penetrating the movable structure 120 is formed in the movable structure 120 , and a second release hole 101 penetrating the base 100 is formed in the base 100 .

[0060] By providing the first release hole 121 in the movable structure 120 and the second release hole 101 in the substrate 100 , it is beneficial to improve the subsequent release rate of the second sacrificial layer 115 .

[0061] In this embodiment, the cross-sectional shapes of the first release hole 121 and the second release hole 101 are both circular. Specifically, the diameter of the first release hole 121 is set to allow the second sacrificial layer 115 to be released through the first release hole 121 while minimally impacting the structural strength of the movable structure 120. Similarly, the diameter of the second release hole 101 is set to allow the second sacrificial layer 115 to be released through the second release hole 101 while minimally impacting the structural strength of the substrate 100.

[0062] Accordingly, depending on the diameter of the first release hole 121, the second sacrificial layer 115 may be filled in the first release hole 121 or may not be filled in the first release hole 121. Similarly, depending on the diameter of the second release hole 101, the second sacrificial layer 115 may be filled in the second release hole 101 or may not be filled in the second release hole 101.

[0063] As an example, the second sacrificial layer 115 is filled in the first release hole 121 and the second release hole 101 .

[0064] In other embodiments, only the movable structure is formed with a first release hole that passes through the movable structure. In still other embodiments, only the base is formed with a second release hole that passes through the base. In other embodiments, the first and second release holes may not be provided.

[0065] In this embodiment, since a component to be mounted is subsequently fixed on the movable structure 120 in the mounting area 120 a , in order to avoid affecting the fixation of the component to be mounted, the first sacrificial layer 140 exposes the mounting area 120 a .

[0066] like Figure 5 As shown, in this embodiment, after the MEMS device 300 is formed, the first sacrificial layer 140 is formed on the MEMS device. The first sacrificial layer 140 covers the top surface of the second sacrificial layer 115 and extends to cover the top surface of the surrounding wall structure 110 and part of the top surface of the movable structure 120.

[0067] Specifically, the first sacrificial layer 140 covers the top surfaces of the movable structure 120 , the second sacrificial layer 115 , and the surrounding wall structure 110 exposed in the mounting area 120 a .

[0068] The first sacrificial layer 140 is used to support the separation of the movable structure 120 from the fixed structure 70. Therefore, during the subsequent removal of the second sacrificial layer 115, the support provided by the first sacrificial layer 140 reduces the probability of surface lamination or adhesion between the movable structure 120 and the fixed structure 70, thereby improving process reliability and correspondingly enhancing the performance of the semiconductor device.

[0069] Moreover, the process of removing the second sacrificial layer 115 has a greater removal rate for the second sacrificial layer 115 than the removal rate for the first sacrificial layer 140. Therefore, after removing the second sacrificial layer 115, the first sacrificial layer 140 suffers less loss, so that the performance of the first sacrificial layer 140 is guaranteed, thereby improving process reliability.

[0070] Subsequently, the component to be installed is fixed on the movable structure 120 in the installation area 120a. Therefore, the first sacrificial layer 140 has the function of fixing the movable structure 120. In the process of fixing the component to be installed, the probability of the movable structure 120 moving is reduced, so that the component to be installed can be accurately fixed on the movable structure 120. Moreover, the first sacrificial layer 140 covers the top surface of the movable structure 120, the second sacrificial layer 115 and the surrounding wall structure 110 exposed in the installation area 120a. Compared with the second sacrificial layer 115, the amount of the first sacrificial layer 140 is smaller, the first sacrificial layer 140 is easy to remove, and the time required to remove the first sacrificial layer 140 is shorter. Therefore, the process of removing the first sacrificial layer 140 has less impact on the component to be installed. Similarly, the process of removing the first sacrificial layer 140 has less impact on the fixed structure 70 and the movable structure 120. Therefore, by forming the first sacrificial layer 140 , the alignment accuracy between the component to be mounted and the movable structure can be improved while reducing the probability of damage to the component to be mounted, thereby improving process reliability.

[0071] In addition, in this embodiment, the first sacrificial layer 140 is formed before removing the second sacrificial layer 115 . The second sacrificial layer 115 can provide a process platform for forming the first sacrificial layer 140 , thereby reducing the process difficulty of forming the first sacrificial layer 140 .

[0072] Therefore, the material of the first sacrificial layer 140 needs to meet the following requirements: when the first sacrificial layer 140 is subsequently removed, the process of removing the first sacrificial layer 140 causes little damage to the fixed structure 70, the movable structure 120, the components to be installed and the electrical connection structure (such as the leads formed by the wire bonding process); moreover, the process of removing the second sacrificial layer 115 causes little damage to the first sacrificial layer 140, so that after the second sacrificial layer 115 is removed, the structural strength of the first sacrificial layer 140 is sufficient to meet the strength requirements of the fixed movable structure 120 and the electrical connection process; in addition, the material of the first sacrificial layer 140 is a material that is easy to remove.

[0073] The first sacrificial layer 140 may be made of silicon oxide, germanium, or carbon. Silicon oxide, germanium, or carbon are all easily removed materials with minimal side effects during the removal process, thereby reducing the impact of the first sacrificial layer 140 removal process on other structures or components.

[0074] Furthermore, the probability of the silicon oxide, germanium or carbon material being exposed on the component to be mounted is low, and therefore, the process of removing the first sacrificial layer 140 has little impact on the component to be mounted.

[0075] In this embodiment, the first sacrificial layer 140 and the second sacrificial layer 115 are made of different materials, so that the first sacrificial layer 140 suffers less damage after the second sacrificial layer 115 is subsequently removed. In other words, the material of the first sacrificial layer 140 is selected based on the material of the second sacrificial layer 115.

[0076] In this embodiment, the second sacrificial layer 115 is made of silicon oxide, and correspondingly, the first sacrificial layer 140 is made of germanium or carbon. Carbon has a high etching selectivity over silicon oxide, and germanium also has a high etching selectivity over silicon oxide. Therefore, during the subsequent removal of the second sacrificial layer 115, the first sacrificial layer 140 suffers minimal loss.

[0077] Furthermore, by selecting germanium or carbon as the material for the first sacrificial layer 140, the impact of the subsequent process of removing the first sacrificial layer 140 on the components to be mounted can be further reduced. For example, damage to the pads of the components to be mounted during the process of removing the first sacrificial layer 140 can be reduced.

[0078] It should be noted that in actual manufacturing processes, the appropriate material for the first sacrificial layer 140 must be selected based on the type of component to be mounted. For example, if the component to be mounted is a CMOS image sensor (CIS) chip with an organic material microlens, the first sacrificial layer 140 should be made of a material other than carbon to prevent damage to the organic material microlens during the ashing process under oxygen conditions.

[0079] In this embodiment, there are multiple first sacrificial layers 140, and the first sacrificial layers 140 are arranged around the movable structure 120. Accordingly, there are gaps between adjacent first sacrificial layers 140, and the gaps expose the second sacrificial layer 115 so that the second sacrificial layer 115 can be released later through the gaps.

[0080] In this embodiment, in the step of forming the first sacrificial layer 140 , at least one release hole 141 is formed in the first sacrificial layer 140 , and the release hole 141 exposes the second sacrificial layer 115 .

[0081] In this embodiment, the release hole 141 is defined as a third release hole. Providing the third release hole in the first sacrificial layer 140 is beneficial for improving the subsequent release rate of the second sacrificial layer 115 .

[0082] In other embodiments, when there is a gap between adjacent first sacrificial layers 140 , the third release hole may not be provided in the first sacrificial layer.

[0083] In this embodiment, the cross-section of the third release holes is circular. Specifically, the diameter of the third release holes is set to be able to release the second sacrificial layer 115 through the third release holes while having little effect on the structural strength of the first sacrificial layer 140 .

[0084] Specifically, the step of forming the first sacrificial layer 140 includes: performing a deposition process to form a supporting material layer (not shown) covering the movable structure 120 , the second sacrificial layer 115 and the surrounding wall structure 110 ; patterning the supporting material layer, and the remaining supporting material layer serves as the first sacrificial layer 140 .

[0085] In this embodiment, the process of forming the support material layer includes a chemical vapor deposition process.

[0086] In this embodiment, a dry etching process (eg, an anisotropic dry etching process) is used to pattern the support material layer, thereby facilitating precise control of the formation position of the first sacrificial layer 140 .

[0087] In this embodiment, the first sacrificial layer 140 can be formed through a single film deposition process and a single patterning process, simplifying the process flow for forming the first sacrificial layer 140. Furthermore, the use of deposition and patterning processes facilitates the formation of the first sacrificial layer 140 in the target area, and the positional and dimensional accuracy of the first sacrificial layer 140 is improved.

[0088] It should be noted that, during the process of patterning the support material layer, the third release hole is formed in the support material layer. The process of forming the third release hole is simple and does not require an additional etching process.

[0089] In this embodiment, the first sacrificial layer 140 covers the movable structure 120, the second sacrificial layer 115 and the top surface of the surrounding wall structure 110 exposed in the installation area 120a, that is, the first sacrificial layer 140 exposes the movable structure 120 in the installation area 120a, so as to facilitate the subsequent fixing of the structure to be installed in the installation area 120a.

[0090] It should be noted that a first connection end (not shown) is formed in the surrounding wall structure 110, and a second connection end (not shown) is formed in the movable structure 120. Therefore, the first sacrificial layer 140 exposes the first and second connection ends, thereby providing a process foundation for subsequent electrical connection processes (e.g., wire bonding processes), thereby enabling the integration of the MEMS device 300 with other components or structures. In the process of patterning the support material layer, the first sacrificial layer 140 exposes the first and second connection ends.

[0091] The thickness T of the first sacrificial layer 140 is at least sufficient to support the separation of the movable structure 120 from the fixed structure 100, that is, to secure the movable structure 120. Therefore, the thickness T of the first sacrificial layer 140 should not be too small. If the thickness T of the first sacrificial layer 140 is too small, the structural strength of the first sacrificial layer 140 itself may be too weak. After the second sacrificial layer 115 is subsequently removed, the first sacrificial layer 140 may not be sufficient to support the separation of the movable structure 120 from the fixed structure 100.

[0092] However, the thickness T of the first sacrificial layer 140 should not be too large. If the thickness T of the first sacrificial layer 140 is too large, it will easily increase the difficulty of the subsequent process of removing the first sacrificial layer 140, which will correspondingly increase the probability of damage to the components to be mounted.

[0093] To this end, in this embodiment, the thickness T of the first sacrificial layer 140 is 0.1 micrometer to 10 micrometers, for example, 1 micrometer, 3 micrometers, 5 micrometers, 7 micrometers, or 9 micrometers.

[0094] refer to Figure 6 After forming the MEMS device 300 and the first sacrificial layer 140, the second sacrificial layer 115 (eg, Figure 5 shown).

[0095] By removing the second sacrificial layer 115 , the movable structure 120 is suspended on the substrate 100 , and thus the movable structure 120 can move during the operation of the semiconductor device.

[0096] Specifically, after removing the second sacrificial layer 115 , the surrounding wall structure 110 and the substrate 100 form a cavity 130 , and the movable structure 120 is located in the cavity 130 , so that the movable structure 120 can move in the cavity 130 .

[0097] At this time, no components to be mounted are installed on the movable structure 120. Therefore, when removing the second sacrificial layer 115, there is no need to consider the requirements of the components to be mounted. This correspondingly avoids the impact of the process of removing the second sacrificial layer 115 on the components to be mounted, and the process flexibility of removing the second sacrificial layer 115 is also higher.

[0098] In this embodiment, in the step of removing the second sacrificial layer 115 , the ratio of the removal rate of the second sacrificial layer 115 to the first sacrificial layer 140 is greater than or equal to 10:1, thereby reducing damage to the first sacrificial layer 140 .

[0099] In this embodiment, the second sacrificial layer 115 is made of silicon oxide. Therefore, a wet etching process is used to remove the second sacrificial layer 115. The etching solution used in the wet etching process is a buffered hydrofluoric acid (BOE) solution or a diluted hydrofluoric acid (DHF) solution. Alternatively, a hydrofluoric acid vapor etching process is used to remove the second sacrificial layer 115. The hydrofluoric acid vapor etching process uses vaporized hydrofluoric acid (VHF). The BOE solution is a mixed solution of hydrofluoric acid (HF) and ammonium fluoride (NH4F), and the DHF solution is a mixed solution of hydrofluoric acid and water (H2O).

[0100] By adopting a wet etching process or a hydrofluoric acid vapor etching process to remove the second sacrificial layer 115 , the second sacrificial layer 115 between the bottom of the movable structure 120 and the substrate 100 can be completely removed with high removal efficiency.

[0101] In some other embodiments, the material of the second sacrificial layer is carbon, and thus, an ashing process is used to remove the second sacrificial layer. Specifically, the gas used in the ashing process includes oxygen (O2). Oxygen has a low cost.

[0102] In other embodiments, the material of the second sacrificial layer is germanium, and the second sacrificial layer can be removed by a wet etching process, wherein the etching solution used in the wet etching process includes a hydrogen peroxide (H2O2) solution, or the second sacrificial layer can be removed by a gasification process, wherein the gas used in the gasification process includes xenon difluoride (XeF2) gas.

[0103] In this embodiment, after removing the second sacrificial layer 115 , the method for manufacturing the semiconductor device further includes: forming an oxide layer (not shown) on the surfaces of the fixed structure 70 and the movable structure 120 .

[0104] The oxide layer is used as a passivation layer. By forming the oxide layer, even if the movable structure 120 approaches or adheres to the substrate 100 due to deformation, the oxide layer located on the bottom surface of the movable structure 120 and the top surface of the substrate 100 will not react further, thereby reducing the probability of adhesion between the movable structure 120 and the substrate 100 due to the production of reaction by-products, and further reducing the probability of failure of the MEMS device 300.

[0105] In this embodiment, the step of forming the oxide layer includes: after removing the second sacrificial layer 115, placing the fixed structure 70 and the movable structure 120 in air for a predetermined time, thereby forming a natural oxide layer on each surface of the substrate 100, the surrounding wall structure 110, and the movable structure 120. By placing the fixed structure 70 and the movable structure 120 in air for a predetermined time, process costs are reduced.

[0106] After releasing the second sacrificial layer 115, the surfaces of the substrate 100, the surrounding wall structure 110 and the movable structure 120 are easily oxidized by being left to stand in the air, especially when the materials of the substrate 100, the surrounding wall structure 110 and the movable structure 120 are materials that can be oxidized (for example, polysilicon or silicon germanium, etc.).

[0107] It should be noted that the preset time should not be too short or too long. If the preset time is too short, it is easy to cause the thickness of the natural oxide layer to be too small, and it is also easy for the formation quality or thickness uniformity of the natural oxide layer to be poor (for example, a natural oxide layer fails to form in some areas), thereby causing the passivation performance of the oxide layer to decrease; if the preset time is too long, it is easy to cause a waste of process time, thereby causing a decrease in yield. For this reason, in this embodiment, the preset time is 0.5 hours to 1.5 hours. For example, the preset time can be 1 hour.

[0108] It should also be noted that the thickness of the natural oxide layer is usually very small, so the oxide layer is not shown in the figure.

[0109] In other embodiments, depending on the high-temperature resistance of the base, surrounding wall structure, and movable structure, the fixed structure and movable structure may be subjected to thermal oxidation treatment to form an oxide layer on each surface of the base, surrounding wall structure, and movable structure. Thermal oxidation treatment can improve the uniformity of the oxidation effect.

[0110] In this embodiment, after forming the oxide layer, the method for manufacturing the semiconductor device further includes: forming an anti-adhesion layer (not shown) on the surfaces of the fixed structure 70 and the movable structure 120 .

[0111] The anti-adhesion layer is used to reduce the probability of adhesion between the movable structure 120 and the substrate 100 .

[0112] Specifically, nanoparticles are deposited onto the surfaces of the fixed structure 70 and the movable structure 120 using an evaporation process to form the anti-adhesion layer. During the evaporation process, gas molecules can enter the cavity 130 , thereby forming nanoparticles on the surfaces of the fixed structure 70 and the movable structure 120 .

[0113] In this embodiment, in order to further reduce the probability of adhesion between the movable structure 120 and the substrate 100 , the anti-adhesion layer is formed on the surface of the oxide layer after the oxide layer is formed.

[0114] refer to Figure 7 , remove the second sacrificial layer 115 (such as Figure 5 As shown), the method further includes: fixing the component 160 to be installed on the movable structure 120 in the installation area 120a.

[0115] The component to be mounted 160 is a functional component. By fixing the component to be mounted 160 on the movable structure 120 , a semiconductor device with a specific function is formed.

[0116] The components to be mounted 160 include one or both of active components and passive components. As an example, the active components include image sensor chips.

[0117] During the process of fixing the component 160 to be mounted on the movable structure 120 in the mounting area 120 a , the first sacrificial layer 140 can fix the movable structure 120 , so that the component 160 to be mounted can be accurately fixed on the movable structure 120 .

[0118] In summary, in this embodiment, before fixing the component to be mounted on the movable structure 120, the first sacrificial layer 140 is formed and the second sacrificial layer 115 is removed. This can improve the alignment accuracy of the component to be mounted 160 and the movable structure 120 while reducing the probability of damage to the component to be mounted 160, thereby improving process reliability.

[0119] In this embodiment, a permanent bonding process is used to secure the component 160 to be mounted to the movable structure 120, thereby improving the bonding strength between the component 160 to be mounted and the movable structure 120 and thereby increasing product yield. Specifically, a permanent bonding layer 150 is used to bond the component 160 to be mounted to the movable structure 120.

[0120] As an example, the permanent bonding layer 150 is a DAF (Die Attach Film) film. DAF film material is a thermosetting material that is generally non-conductive. At room temperature, it is a double-sided adhesive polymer colloid material. When the temperature reaches the glass transition temperature, it will undergo irreversible curing. After curing, it can ensure that both sides of the DAF film have stable adhesion and increased adhesion, and it has good heat resistance, so that the bonding strength between the component to be mounted 160 and the movable component 120 is guaranteed. In addition, DAF film is an ultra-thin film adhesive commonly used in the field of semiconductor packaging. It has high process compatibility and a simple formation process, which reduces the process complexity of achieving permanent bonding.

[0121] In other embodiments, the permanent bonding layer is a dry film. Dry film is an adhesive photosensitive polymer material used in semiconductor chip packaging or printed circuit board manufacturing. Dry film is a permanent bonding film with high bonding strength, which improves the bonding force between the component to be mounted and the movable structure.

[0122] As an example, the permanent bonding layer 150 corresponds to an edge position of the component to be mounted 160 , and the permanent bonding layer 150 is annular.

[0123] It should be noted that after the component to be mounted 160 is fixed to the movable structure 120 , the method for manufacturing the semiconductor device may further include: performing an electrical connection process to achieve electrical connection between the component to be mounted 160 , the movable structure 120 and the surrounding wall structure 110 .

[0124] Specifically, a wire bonding process is used to form leads, which connect the component to be mounted 160 and the movable structure 120 . The leads also connect the movable structure 120 and the surrounding wall structure 110 .

[0125] As an example, the component to be mounted 160 , the movable structure 120 and the surrounding wall structure 110 are electrically connected through the first connection end and the second connection end.

[0126] refer to Figure 8 After fixing the component 160 to be mounted on the movable structure 120 in the mounting area 120a, the first sacrificial layer 140 (eg Figure 7 shown).

[0127] By removing the first sacrificial layer 140 , the movable structure 120 can move in the cavity 130 , thereby achieving normal performance of the semiconductor device.

[0128] In this embodiment, the first sacrificial layer 140 covers the top surfaces of the movable structure 120, the second sacrificial layer 115 and the surrounding wall structure 110 exposed in the installation area 120a. The amount of the first sacrificial layer 140 is small, so the first sacrificial layer 140 is easy to remove, and the time required to remove the first sacrificial layer 140 is short. Therefore, the process of removing the first sacrificial layer 140 has little impact on the component 160 to be installed.

[0129] Moreover, the first sacrificial layer 140 is formed on the surface of the MEMS device 300, and the thickness T of the first sacrificial layer 140 (eg Figure 5 As shown in FIG, the thickness of the first sacrificial layer 140 is smaller, which further reduces the difficulty of removing the first sacrificial layer 140.

[0130] Depending on the material of the first sacrificial layer 140, a wet etching process, a hydrofluoric acid vapor etching process, or a gasification process can be used to remove the first sacrificial layer 140. By using a wet etching process, a hydrofluoric acid vapor etching process, or a gasification process, the first sacrificial layer 140 can be completely removed.

[0131] In this embodiment, the material of the first sacrificial layer 140 is carbon, so an ashing process is used to remove the first sacrificial layer 140. Specifically, the gas used in the ashing process includes oxygen.

[0132] In other embodiments, when the material of the first sacrificial layer is germanium, a gasification process is used to remove the first sacrificial layer, and the gas used in the gasification process includes xenon difluoride (XeF2) gas, or a wet etching process is used to remove the first sacrificial layer, and the etching solution used in the wet etching process includes hydrogen peroxide (H2O2) solution.

[0133] In other embodiments, when the material of the first sacrificial layer is silicon oxide, a wet etching process is used to remove the first sacrificial layer, and the etching solution used in the wet etching process is a buffered hydrofluoric acid solution or a diluted hydrofluoric acid solution. Alternatively, a hydrofluoric acid vapor etching process is used to remove the first sacrificial layer, and the hydrofluoric acid vapor etching process uses steam hydrofluoric acid.

[0134] Figure 9 It is a structural schematic diagram of a MEMS device and a first sacrificial layer in another embodiment of the method for manufacturing a semiconductor device of the present invention.

[0135] The similarities between this embodiment and the previous embodiment are not repeated here. The difference between this embodiment of the present invention and the previous embodiment is that: the first sacrificial layer 240 is formed in the process of forming the MEMS device, and the first sacrificial layer 240 is located between part of the movable structure 220 and the substrate 200, and is embedded in the second sacrificial layer 215.

[0136] The first sacrificial layer 240 is located between part of the movable structure 220 and the substrate 200 and is embedded in the second sacrificial layer 215. The first sacrificial layer 240 can also provide fixed support for the movable structure 220 and the fixed structure 80, thereby supporting the separation of the movable structure 220 from the fixed structure 80.

[0137] By positioning the first sacrificial layer 240 between a portion of the movable structure 220 and the substrate 200 and embedded within the second sacrificial layer 215, the first sacrificial layer 240 not only secures the movable structure 220 in a direction parallel to the surface of the substrate 200, but also provides longitudinal support for the movable structure 220 perpendicular to the surface of the substrate 200, thereby providing better support and stability for the movable structure 220. Consequently, after the second sacrificial layer 215 is subsequently removed, the probability of deformation of the movable structure 220 is reduced, thereby reducing the probability of the movable structure 220 and the substrate 200 becoming attached or adhered.

[0138] Moreover, when the component to be installed is subsequently fixed to the movable structure 220, the first sacrificial layer 240 has the function of fixing the movable structure 220, so that the component to be installed can be accurately fixed on the movable structure 220, and the movable structure 220 is easily subjected to longitudinal downward pressure. Under the support of the first sacrificial layer 240, the probability of deformation of the movable structure 220 is also low.

[0139] As an example, the steps of forming the second sacrificial layer 215, the first sacrificial layer 240 and the movable structure 220 include: forming the first sacrificial layer 240 on the substrate 200 through a deposition process and a patterning process performed in sequence; forming a bottom sub-sacrificial layer 215b on the substrate 200 where the first sacrificial layer 240 is exposed through a deposition process and a planarization process performed in sequence, and the top of the bottom sub-sacrificial layer 215b is flush with the top of the first sacrificial layer 240; forming the movable structure 220 on the bottom sub-sacrificial layer 215b and the first sacrificial layer 240 through a deposition process and a patterning process performed in sequence; forming a top sub-sacrificial layer 215a on the bottom sub-sacrificial layer 215b exposed from the movable structure 220 through a deposition process and a planarization process performed in sequence, and the top of the top sub-sacrificial layer 215a is flush with the top of the movable structure 220, and the top sub-sacrificial layer 215a and the bottom sub-sacrificial layer 215b constitute the second sacrificial layer 215.

[0140] In other embodiments, the steps of forming the second sacrificial layer, the first sacrificial layer and the movable structure include: forming a bottom sub-sacrificial layer on the substrate; forming an opening (not shown) in the bottom sub-sacrificial layer, the opening exposing the substrate; filling the opening with a sacrificial material layer; flattening the sacrificial material layer, retaining the sacrificial material layer in the opening as the first sacrificial layer; forming a movable structure on the first sacrificial layer and the bottom sub-sacrificial layer; forming a top sub-sacrificial layer on the bottom sub-sacrificial layer exposed by the movable structure, the top sub-sacrificial layer covering the side walls of the movable structure, and the top sub-sacrificial layer and the bottom sub-sacrificial layer constituting a second sacrificial layer.

[0141] In other embodiments, the steps of forming the second sacrificial layer, the first sacrificial layer and the movable structure include: forming a first sacrificial layer on the substrate; forming a second sacrificial layer covering the substrate and the first sacrificial layer; removing a portion of the thickness of the second sacrificial layer, and forming a groove in the second sacrificial layer to expose the first sacrificial layer; and forming a movable structure in the groove.

[0142] It should be noted that the steps of forming the second sacrificial layer, the first sacrificial layer and the movable structure are not limited to the above-mentioned method. In actual processes, other methods can also be used to form the second sacrificial layer, the first sacrificial layer and the movable structure.

[0143] For the detailed description of the MEMS device 400 and the first sacrificial layer 240 , reference may be made to the corresponding descriptions in the aforementioned embodiments, which will not be repeated here.

[0144] The subsequent process is the same as that of the above embodiment, and will not be described in detail in this embodiment. For the detailed description of the forming method of this embodiment, reference can be made to the corresponding description in the above embodiment, and will not be described in detail in this embodiment.

[0145] Figures 10 and 11 This is a schematic structural diagram corresponding to each step in another embodiment of the method for manufacturing a semiconductor device of the present invention.

[0146] The similarities between this embodiment and the aforementioned embodiment are not repeated here. The difference between this embodiment of the present invention and the aforementioned embodiment is that the movable structure 510 and the fixed structure are further fixedly supported by a fixing plug 540b.

[0147] Specifically, the fixing plug 540b penetrates the movable structure 510 and the second sacrificial layer 525 and contacts the substrate 500. The fixing plug 540b is also used to support the separation of the movable structure 510 from the fixed structure. The fixing plug 540b further reduces the probability of adhesion or sticking between the movable structure 510 and the substrate 500.

[0148] Moreover, when the component to be installed is subsequently fixed to the movable structure 210, the fixing plug 540 can further improve the deformation and lateral movement problems of the movable structure 510, thereby reducing the probability of the movable structure 510 and the substrate 500 being fitted or adhered, and improving the alignment accuracy of the component to be installed and the movable structure 510.

[0149] refer to Figure 10 Before forming the first sacrificial layer, the method for manufacturing the semiconductor device further includes: forming at least one fixing hole 515 in the MEMS device, wherein the fixing hole 515 penetrates the movable structure 510 and the second sacrificial layer 525 and exposes the substrate 500 .

[0150] The fixing hole 515 is used to provide a space for the subsequent formation of a fixing plug.

[0151] In this embodiment, the fixing hole 515 is formed before removing the second sacrificial layer 525 .

[0152] The second sacrificial layer 525 can support the movable structure 510 during the process of forming the fixing hole 515, thereby reducing the process difficulty of forming the fixing hole 515 and improving the position accuracy and dimensional accuracy of the fixing hole 515. Moreover, it is beneficial to reduce the probability of deformation of the movable structure 510 during the process of forming the fixing hole 515.

[0153] In this embodiment, a dry etching process (for example, an anisotropic dry etching process) is used to sequentially etch the movable structure 510 and the second sacrificial layer 525 , thereby facilitating precise control of the stop position of the etching process and improving the dimensional accuracy of the fixing hole 515 .

[0154] It should be noted that, in order to improve the uniformity of the supporting force provided by the subsequent fixing plugs, there are multiple fixing holes 515, and the fixing holes 515 are evenly distributed in the MEMS device.

[0155] The first sacrificial layer will be removed later. Therefore, the number and lateral dimensions of the fixing holes 515 are set to minimize the impact on the structural strength of the movable structure 510. The lateral dimensions of the fixing holes 515 refer to the dimensions of the fixing holes 515 along a direction parallel to the surface of the movable structure 510. For example, when the cross-sectional shape of the fixing holes 515 is circular, the lateral dimensions of the fixing holes 515 are the aperture diameters.

[0156] It should also be noted that increasing the number of the fixing holes 515 correspondingly increases the density of the fixing plugs, thereby increasing the supporting force of the fixing plugs. In this embodiment, the spacing between adjacent fixing holes 515 is less than or equal to 10,000 times the spacing between the movable structure 510 and the surrounding wall structure 520.

[0157] refer to Figure 11 , forming a first sacrificial layer 540, the first sacrificial layer 540 covers the top surface of the movable structure 510, the second sacrificial layer 525 and the surrounding wall structure 520 exposed in the mounting area (not shown), and in the process of forming the first sacrificial layer 540, the fixing hole 515 (such as Figure 10 As shown in FIG, a fixed plug 540b is formed.

[0158] The first sacrificial layer 540 and the fixed plug 540 b are formed in the same step, thereby simplifying the process steps.

[0159] Therefore, the first sacrificial layer 540 and the fixed plug 540b are made of the same material. In the subsequent step of removing the first sacrificial layer 540, the fixed plug 540b is also removed. Accordingly, the first sacrificial layer 540 and the fixed plug 540b are removed in the same step, thereby simplifying the process steps.

[0160] In this embodiment, the fixing plug 540b also extends to cover a portion of the top surface of the movable structure 510 surrounding the fixing hole 515, thereby increasing the contact area between the fixing plug 540b and the movable structure 510 and further enhancing the supporting strength of the fixing plug 540b. Accordingly, the fixing plug 540b has a T-shaped structure.

[0161] It should be noted that the component to be mounted is subsequently fixed to the movable structure 510 in the mounting area. When the top surface of the fixing pin 540 b is higher than the top surface of the movable structure 510, the distance from the top surface of the fixing pin 540 b to the top surface of the movable structure 510 is a first distance, and the preset distance from the bottom surface of the component to be mounted to the top surface of the movable structure 510 is a second distance. To prevent adverse effects on the installation of the component to be mounted, the first distance is less than or equal to the second distance.

[0162] For a detailed description of the first sacrificial layer 540 and a method for forming the same, reference may be made to the corresponding description in the aforementioned embodiments, which will not be repeated here.

[0163] For the specific description of the forming method described in this embodiment, reference can be made to the corresponding description in the aforementioned embodiment, and this embodiment will not be repeated here.

[0164] Correspondingly, the present invention further provides an electronic device, which includes a semiconductor device formed by the manufacturing method described in the above embodiment.

[0165] Since the manufacturing method has high process reliability, the performance of the semiconductor device is high, and the performance and yield of the electronic device are correspondingly improved.

[0166] In this embodiment, the electronic device can be any electronic product or equipment such as a mobile phone, tablet computer, laptop computer, netbook, game console, television, VCD, DVD, navigator, camera, camcorder, voice recorder, MP3, MP4, PSP, etc., or any intermediate product including the semiconductor device.

[0167] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A method for manufacturing a semiconductor device, characterized in that: include: forming a MEMS device and a first sacrificial layer, wherein the MEMS device includes a fixed structure including a base and a surrounding wall structure surrounding the base, the MEMS device also includes a movable structure suspended above the base, and a second sacrificial layer located between the movable structure and the fixed structure, wherein the first sacrificial layer is used to fix the movable structure to support the movable structure from being separated from the fixed structure; After forming the MEMS device and the first sacrificial layer, removing the second sacrificial layer; After removing the second sacrificial layer, the first sacrificial layer is removed; wherein the process of removing the second sacrificial layer has a greater removal rate for the second sacrificial layer than a removal rate for the first sacrificial layer; After forming the MEMS device, forming the first sacrificial layer on the MEMS device, the first sacrificial layer covers the top surface of the second sacrificial layer and extends to cover the top surface of the surrounding wall structure and part of the top surface of the movable structure; or, During the process of forming the MEMS device, the first sacrificial layer is formed; the first sacrificial layer is located between a portion of the movable structure and a portion of the substrate, and is embedded in the second sacrificial layer.

2. The manufacturing method according to claim 1, wherein The movable structure includes a mounting area, and the first sacrificial layer exposes the mounting area; After removing the second sacrificial layer and before removing the first sacrificial layer, the manufacturing method further includes: fixing a component to be mounted on the movable structure in the mounting area.

3. The manufacturing method according to claim 1, wherein: After forming the MEMS device and before forming the first sacrificial layer on the MEMS device, the manufacturing method further includes: forming at least one fixing hole in the MEMS device, the fixing hole penetrating the movable structure and the second sacrificial layer and exposing the substrate; In the step of forming the first sacrificial layer, a fixing plug is further formed in the fixing hole; In the step of removing the first sacrificial layer, the fixing plug is also removed.

4. The manufacturing method according to claim 3, wherein: In the step of forming the fixing plug, the fixing plug further extends to cover a portion of the top surface of the movable structure around the fixing hole.

5. The manufacturing method according to claim 1, wherein: After forming the MEMS device, in the step of forming the first sacrificial layer on the MEMS device, at least one release hole is formed in the first sacrificial layer, and the release hole exposes the second sacrificial layer.

6. The manufacturing method according to claim 1, wherein: After forming the MEMS device, the step of forming the first sacrificial layer on the MEMS device includes: performing a deposition process to form a support material layer covering the movable structure, the second sacrificial layer and the surrounding wall structure; patterning the support material layer, and the remaining support material layer serves as the first sacrificial layer.

7. The manufacturing method according to claim 1, wherein: After removing the second sacrificial layer and before removing the first sacrificial layer, the manufacturing method further includes: forming an oxide layer on surfaces of the fixed structure and the movable structure.

8. The manufacturing method according to claim 7, wherein: The step of forming the oxide layer includes: placing the fixed structure and the movable structure in air for a preset time; or, The fixed structure and the movable structure are subjected to thermal oxidation treatment.

9. The manufacturing method according to claim 8, wherein: The preset time is 0.5 hours to 1.5 hours.

10. The manufacturing method according to claim 1 or 7, wherein: Before removing the first sacrificial layer, the manufacturing method further includes: forming an anti-adhesion layer on the surfaces of the fixed structure and the movable structure.

11. The manufacturing method according to claim 10, wherein: The anti-adhesion layer is formed by adopting an evaporation process.

12. The manufacturing method according to claim 1, wherein A ratio of a removal rate of the second sacrificial layer to a removal rate of the first sacrificial layer in a process of removing the second sacrificial layer is greater than or equal to 10:

1.

13. The manufacturing method according to claim 1, wherein: The second sacrificial layer and the first sacrificial layer are made of different materials.

14. The manufacturing method according to claim 1, wherein: The material of the second sacrificial layer includes silicon oxide, germanium or carbon, and the material of the first sacrificial layer includes silicon oxide, germanium or carbon.

15. The manufacturing method according to claim 1, wherein: The thickness of the first sacrificial layer is 0.1 micrometers to 10 micrometers.

16. The manufacturing method according to claim 1, wherein: The second sacrificial layer is removed by using a wet etching process, a hydrofluoric acid vapor etching process, a gasification process or an ashing process.

17. The manufacturing method according to claim 1, wherein: The first sacrificial layer is removed by using a wet etching process, a hydrofluoric acid vapor etching process, a gasification process or an ashing process.

18. The manufacturing method according to claim 1, wherein: In the step of forming the MEMS device, in a direction perpendicular to the surface of the substrate, a distance between the movable structure and the substrate is less than or equal to 5 microns.

19. The manufacturing method according to claim 1, wherein: In the step of forming the MEMS device, the distance between the movable structure and the surrounding wall structure in a direction parallel to the surface of the substrate is a first distance, and the distance between the movable structure and the substrate in a direction perpendicular to the surface of the substrate is a second distance; The first spacing is greater than or equal to 10 times the second spacing.

20. The manufacturing method according to claim 2, wherein: The components to be mounted include one or both of active components and passive components.

21. The manufacturing method according to claim 20, wherein: The active component includes an image sensor chip.

22. An electronic device, characterized in that: A semiconductor device formed by the method for manufacturing a semiconductor device according to any one of claims 1 to 21.

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