MEMS device, manufacturing method thereof and chemical vapor deposition device

Abstract

The invention discloses an MEMS device, a manufacturing method thereof and a chemical vapor deposition device, and the manufacturing method comprises the steps: providing a semiconductor substrate, and placing the semiconductor substrate in a reaction chamber; executing a pre-deposition step, and introducing first reaction gas into the reaction chamber so as to deposit a transition layer capable of promoting GexHy decomposition on the surface of the semiconductor substrate; and a deposition step is executed, and second reaction gas including GexHy gas is introduced into the reaction chamber so that a germanium film layer can be deposited on the surface of the transition layer. The surface chromatic aberration problem of the germanium film layer can be improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a MEMS device and a manufacturing method thereof, and a chemical vapor deposition device. Background Art

[0002] Wafer bonding is an important process step in the MEMS (Micro-Electro-Mechanical System) manufacturing process. Its functions in MEMS devices mainly include: mechanical protection, a certain gas atmosphere, or sealing under vacuum requirements.

[0003] Among them, aluminum-germanium bonding is the most commonly used wafer-level bonding. On the one hand, it has the advantage of being compatible with production line processes and free of heavy metal ion pollution. On the other hand, germanium and silicon (Si) are elements of the same family, so many process conditions can draw on current mature process conditions.

[0004] In the aluminum-germanium bonding process, a germanium film layer needs to be formed on one of the semiconductor substrates first, and then the germanium film layer is etched to form a patterned germanium bonding layer. However, the germanium film layer prepared by the existing preparation process has obvious color difference in the macroscopic view. Summary of the invention

[0005] A series of simplified concepts are introduced in the Summary of the Invention, which will be further described in detail in the Detailed Description of the Invention. The Summary of the Invention does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0006] In view of the existing problems, an embodiment of the present invention provides a method for manufacturing a MEMS device, the manufacturing method comprising:

[0007] Providing a semiconductor substrate, and placing the semiconductor substrate in a reaction chamber;

[0008] Perform a pre-deposition step, introduce a first reaction gas into the reaction chamber to deposit a Ge-promoting x H y Decomposed transition layer;

[0009] Perform the deposition step, introduce Ge into the reaction chamber x H y The second reaction gas of the gas is used to deposit a germanium film layer on the surface of the transition layer.

[0010] In some embodiments of the present application, the transition layer includes an amorphous silicon film layer, and the first reaction gas includes Si x H y gas.

[0011] In some embodiments of the present application, the manufacturing method further includes: before introducing the first reaction gas into the reaction chamber, adjusting the pressure in the reaction chamber to less than 10 mt.

[0012] In some embodiments of the present application, the thickness of the transition layer is less than

[0013] In some embodiments of the present application, the manufacturing method further includes: etching the germanium film layer and the transition layer to form a patterned germanium bonding layer.

[0014] A second aspect of an embodiment of the present invention provides a MEMS device, the MEMS device comprising: a semiconductor substrate and a germanium bonding layer, wherein the germanium bonding layer is arranged on the semiconductor substrate and is located in an edge region of the semiconductor substrate, the germanium bonding layer comprises: a transition layer and a germanium film layer covering the transition layer, the transition layer is configured to promote Ge x H y break down.

[0015] In some embodiments of the present application, the MEMS device further includes: a cap substrate, a metal bonding layer is provided on a side of the cap substrate facing the semiconductor substrate, and the cap substrate and the semiconductor substrate are bonded via the germanium bonding layer and the metal bonding layer.

[0016] A third aspect of an embodiment of the present invention provides a chemical vapor deposition device, the chemical vapor deposition device comprising:

[0017] A reaction chamber extending in a vertical direction;

[0018] A wafer boat is arranged in the reaction chamber, and is used to carry a plurality of semiconductor substrates arranged at intervals in a vertical direction;

[0019] A driving mechanism for driving the wafer boat to rotate along its vertical axis;

[0020] A pressure regulating device, used to adjust the pressure in the reaction chamber;

[0021] A temperature regulating device, used for regulating the temperature in the reaction chamber;

[0022] An air inlet pipe is arranged in the reaction chamber, and the air inlet pipe is distributed at intervals on the outside of the wafer boat along the circumference of the wafer boat;

[0023] The gas inlet pipe is configured to: when performing the pre-deposition step, introduce the first reaction gas into the reaction chamber to deposit a gas on the surface of the semiconductor substrate that can promote Ge x H y Decomposed transition layers; and,

[0024] During the deposition step, a gas including Ge is introduced into the reaction chamber. x H yA second reaction gas is used to deposit a germanium film layer on the surface of the transition layer.

[0025] In some embodiments of the present application, the air inlet pipe includes: a first air inlet pipe, a second air inlet pipe and a third air inlet pipe; wherein the first air inlet pipe to the third air inlet pipe are respectively provided with a first air jet port to a third air jet port, and the first air jet port to the third air jet port are respectively provided close to the bottom area of ​​the reaction chamber, the middle area of ​​the wafer boat, and the top area of ​​the wafer boat in the vertical direction;

[0026] The first air inlet pipe to the third air inlet pipe are configured as follows: when performing the pre-deposition step, the gas flow rates of the first reaction gas introduced into the reaction chamber by the first air inlet pipe to the third air inlet pipe are respectively the first set gas flow rate, the second set gas flow rate and the third set gas flow rate; wherein the first set gas flow rate is greater than the second set gas flow rate and the third set gas flow rate, so that the thickness deviation of the transition layer is controlled within the first set range.

[0027] In some embodiments of the present application, the air intake pipe further includes: a fourth air intake pipe and a fifth air intake pipe; wherein the fourth air intake pipe is provided with a plurality of fourth air injection ports, and the fifth air intake pipe is provided with a plurality of fifth air injection ports; the plurality of fourth air injection ports are distributed in a lower half of the reaction chamber at intervals along the vertical direction, and the plurality of fifth air injection ports are distributed in an upper half of the reaction chamber at intervals along the vertical direction;

[0028] The second reaction gas includes Ge x H y and B x Cl y The first to fifth inlet pipes are configured as follows: when performing the deposition step, the first to third inlet pipes introduce Ge into the reaction chamber. x H y Gas, the fourth inlet pipe and the fifth inlet pipe are connected to the reaction chamber B x Cl y Gas, and the gas flow rates of the first to fifth inlet pipes are respectively the fourth set gas flow rate to the eighth set gas flow rate; wherein the fourth set gas flow rate is greater than the fifth set gas flow rate and the sixth set gas flow rate, and the fifth set gas flow rate and the sixth set gas flow rate are both greater than the seventh set gas flow rate and the eighth set gas flow rate, so that the thickness deviation of the germanium film layer is controlled within the second set range.

[0029] According to the MEMS device and the manufacturing method thereof and the chemical vapor deposition device provided by the present invention, by first performing a pre-deposition step, a first reaction gas is introduced into the reaction chamber to deposit a gas on the surface of the semiconductor substrate that can promote Ge x H y The decomposed transition layer, since the transition layer covers the entire surface of the semiconductor substrate and can promote Ge x H yDecomposition eliminates the different proportions of bare silicon area on the semiconductor substrate, Ge x H y The formation of the Ge film during the decomposition process has a long initial deposition time, and germanium is not deposited at all on some semiconductor substrates, which affects the deposition quality of the germanium film layer. Therefore, after the deposition step is performed, the surface color difference problem of the germanium film layer can be improved; and it is beneficial to improve the quality of the germanium bonding layer formed based on the germanium film layer, thereby improving the bonding quality when the semiconductor substrate is metal-bonded to other substrates through the germanium bonding layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The following drawings of the present invention are used to understand the present invention as part of the present invention. The embodiments of the present invention are shown in the drawings and the description thereof is used to explain the principle of the present invention.

[0031] In the attached figure:

[0032] Figure 1 A flow chart showing a method for manufacturing a MEMS device according to a specific embodiment of the present invention;

[0033] FIG. 2A to FIG. 2D Partial cross-sectional schematic diagrams of various steps in a process of manufacturing a MEMS device according to a specific embodiment of the present invention are respectively shown;

[0034] FIG. 3A to FIG. 3B Schematic cross-sectional views of MEMS devices according to different specific embodiments of the present invention are shown respectively;

[0035] Figure 4 A partial structural schematic diagram of a chemical vapor deposition device according to a specific embodiment of the present invention is shown;

[0036] Figure 5 A schematic diagram of the electronic scanning comparison of the germanium film before and after improvement is shown;

[0037] Figure 6 A partial schematic diagram of a whitish area of ​​a germanium film layer prepared by an existing process under an electron scanning microscope;

[0038] Figure 7 It is a partial schematic diagram of a germanium film layer prepared by a method for manufacturing a MEMS device according to a specific embodiment of the present invention under an electron scanning microscope. DETAILED DESCRIPTION

[0039] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0040] It should be understood that the present invention can be implemented in different forms and should not be construed as being limited to the embodiments presented herein. On the contrary, providing these embodiments will make the disclosure thorough and complete and fully convey the scope of the present invention to those skilled in the art. In the accompanying drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. The same reference numerals throughout represent the same elements.

[0041] It should be understood that when an element or layer is referred to as being "on, adjacent to, connected to or coupled to other elements or layers, it may be directly on, adjacent to, connected to or coupled to other elements or layers, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on, directly adjacent to, directly connected to or directly coupled to other elements or layers, there may be no intervening elements or layers. It should be understood that, although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer or part discussed below may be represented as a second element, component, region, layer or part.

[0042] Spatially relative terms such as "under," "below," "below," "under," "above," "above," etc., may be used herein for ease of description to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that in addition to the orientations shown in the figures, the spatially relative terms are intended to include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, then the elements or features described as "under other elements" or "under" or "under" will be oriented as "on" the other elements or features. Therefore, the exemplary terms "under" and "under" may include both upper and lower orientations. The device may be oriented otherwise (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0043] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present invention. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0044] The existing germanium film preparation process combines the low-pressure chemical vapor deposition process, which uses the equipment used in the existing polysilicon deposition process. 4 Decomposition produces the required Ge (germanium) film. Figure 5 , the germanium film produced by the existing preparation process has obvious color difference in the macroscopic view. Figure 6 , a schematic diagram of the scanning image of the whitish area of ​​the germanium film layer prepared by the existing preparation process under a microscopic electron scanning microscope. It can be seen that there is hydrogen in the Ge film that is not removed in time and is deposited on the semiconductor substrate, resulting in incomplete deposition of the germanium film, so that the Ge film layer has obvious color difference in the macroscopic view.

[0045] Therefore, in view of the existence of the aforementioned technical problems, reference Figure 1 The present invention provides a method for manufacturing a MEMS device, which mainly includes the following steps:

[0046] In step S101, a semiconductor substrate is provided and placed in a reaction chamber;

[0047] In step S102, a pre-deposition step is performed, and a first reaction gas is introduced into the reaction chamber to deposit a gas on the surface of the semiconductor substrate that can promote Ge x H y Decomposed transition layer;

[0048] In step S103, a deposition step is performed to introduce Ge into the reaction chamber. x H y The second reaction gas of the gas is used to deposit a germanium film layer on the surface of the transition layer.

[0049] The specific principle is as follows: The current GeH 4 The film formed by decomposition deposition at 350°C shows color difference in the macroscopic view. At the same time, the color difference is positively correlated with the number of wafers in the deposition process and the area ratio of bare silicon on the semiconductor substrate. When the color difference is slight, it shows a spiral shape. The applicant found that GeH 4The formation of Ge film during the decomposition process has a longer initial deposition time, or Ge will not be deposited at all on some material layers of the semiconductor substrate, which is the reason for GeH 4 The decomposition process increases the difficulty of removing H (hydrogen), which leads to color difference in the prepared germanium film.

[0050] In the above embodiment of the present application, a pre-deposition step is performed first, and a first reaction gas is introduced into the reaction chamber to deposit a gas on the surface of the semiconductor substrate that can promote Ge x H y Decomposed transition layer. Since the transition layer covers the entire surface of the semiconductor substrate, the influence of different bare silicon area ratios of the semiconductor substrate is eliminated. And the transition layer can promote Ge x H y decomposition, which shortens the Ge x H y The initial deposition time of Ge film formed during the decomposition process reduces the Ge x H y The difficulty of removing H during the decomposition process also eliminates the influence of the deposition quality of the germanium film layer on the non-deposition of germanium on some material layers of the semiconductor substrate. Therefore, after the deposition step is performed, the quality of the deposited germanium film layer can be improved, and the surface color difference problem of the germanium film layer can be improved. The effect can be seen by comparing Figure 6 and Figure 7 Reference Figure 6 The Ge thin film prepared by the existing process shown in FIG. 1 has H deposited on the semiconductor substrate before it is removed in time, resulting in incomplete deposition of the germanium film, which makes the Ge thin film have obvious color difference in the macroscopic view. Figure 7 The germanium film layer manufactured by the manufacturing method of the present application is shown to be complete, so that the surface color difference problem of the germanium film layer can be significantly improved. With the improvement of the quality of the formed germanium film layer, it is also beneficial to improve the quality of the germanium bonding layer formed based on the germanium film layer, thereby improving the bonding quality when the semiconductor substrate is metal-bonded to other substrates through the germanium bonding layer.

[0051] Below, reference FIG. 2A to FIG. 2D The manufacturing method of the MEMS device according to the embodiment of the present invention is described in detail.

[0052] First, refer to Figure 2A , provide a semiconductor substrate 200, and place the semiconductor substrate 200 in a reaction chamber.

[0053] It should be noted that various types of device structures may be disposed on the semiconductor substrate 200 in this step. Figure 2AThe semiconductor substrate 200 includes a base 201 and a device layer 202 formed on the base 201. Various types of device structures such as but not limited to conductive plugs, metal lines, pads, micromechanical structures, capacitors, inductors, etc. can be provided in the device layer 202.

[0054] The above-mentioned substrate 201 can be any type of semiconductor substrate. Exemplarily, the semiconductor substrate can be silicon or silicon on insulator (SOI). For example, the semiconductor substrate can be a Si-containing semiconductor substrate. The term "Si-containing semiconductor substrate" refers to any semiconductor material containing at least silicon. Illustrative examples of Si-containing semiconductor materials that can be used as substrates include: Si, SiGe, SiC, SiGeC, silicon on insulator (SOI) or SiGe on insulator (SGOI), but are not limited thereto. Depending on the device being manufactured, the substrate can be undoped or doped. Exemplarily, the semiconductor substrate can be made of single crystal silicon material.

[0055] It should be noted that the number of semiconductor substrates 200 placed in the reaction chamber may be one or more, and the multiple semiconductor substrates 200 are placed in the reaction chamber at intervals.

[0056] Next, refer to Figure 2B , perform a pre-deposition step, introduce a first reaction gas into the reaction chamber to deposit a Ge x H y Decomposed transition layer 203.

[0057] The material type of the transition layer 203 is related to the type of the first reaction gas, ensuring that the first reaction gas can react in the reaction chamber to deposit on the surface of the semiconductor substrate 200 to form the transition layer 203. The material of the transition layer 203 can be any material that can promote Ge x H y The decomposed material, that is, the material of the transition layer 203 is Ge x H y Decomposing catalytic materials with catalytic effects. Some exemplary methods are introduced below.

[0058] For example, the transition layer 203 may include an amorphous silicon (Amorphous silicon, also known as amorphous silicon) film layer, that is, the result of performing the pre-deposition step is to deposit an amorphous silicon film layer on the surface of the semiconductor substrate 200. x H y Decomposition provides a suitable culture dish for improving Ge x H y The decomposition rate of Ge x H y Fully decompose and reduce GeH4 The difficulty of removing H during decomposition is to shorten Ge x H y The starting deposition time of Ge film formed during the decomposition process.

[0059] For example, when the transition layer 203 includes an amorphous silicon film layer, the first reaction gas may include Si x H y Gas. Through Si x H y The gas decomposes to deposit an amorphous silicon film layer on the surface of the semiconductor substrate 200 .

[0060] About Si x H y Gas type, any type of Si can be used x H y Gas. For example, Si x H y The gas may include Si 2 H 6 Any Si composed of silicon and hydrogen and relatively active x H y gas.

[0061] Exemplarily, the manufacturing method may further include: before the first reaction gas is introduced into the reaction chamber, adjusting the pressure in the reaction chamber to less than 10 mt. For example, the pressure in the reaction chamber may be controlled to any value less than 10 mt such as 5 mt, 6 mt, 7 mt, 8 mt, 9 mt, etc., so as to adjust the pressure in the reaction chamber to an extreme vacuum environment less than 10 mt, thereby increasing the free path of the first reaction gas molecules, for example, increasing the Si x H y The free path of the gas molecules ensures the consistency of the thickness of the amorphous silicon layer at the edge and center of the semiconductor substrate 200, and ensures that the thickness deviation of the transition layer 203 is controlled within a smaller first set range, so as to improve the uniformity of the thickness of the transition layer 203 and promote the uniformity of the thickness of the germanium film layer subsequently deposited.

[0062] Exemplarily, the manufacturing method may further include: during the pre-deposition step, adjusting the temperature of the reaction chamber to a set temperature. The set temperature may be a relatively low set temperature, that is, the set temperature is a low temperature, so as to provide a reaction temperature required for depositing an amorphous silicon film layer at a low temperature, and preparing the transition layer 203 by a low-temperature chemical vapor deposition process, thereby improving the quality of the transition layer 203.

[0063] Regarding the thickness of the transition layer 203, it can be any relatively thin thickness value. For example, the thickness of the transition layer 203 can be less than Specifically, the thickness of the transition layer 203 may be Equal to or less than Any thickness. x H y The decomposition provides a suitable culture dish environment, and the thickness of the transition layer 203 is reduced as much as possible to avoid affecting the conductive properties between the formed germanium film layer and the semiconductor substrate 200.

[0064] When the first reaction gas is introduced into the reaction chamber, the gas flow rate of the first reaction gas and the position of the gas inlet may be adjusted to improve the thickness uniformity and consistency of the deposited transition layer 203 . This may be done in a variety of ways.

[0065] Exemplary, reference Figure 4 The reaction chamber 10 is provided with first to third air inlet pipes 31 to 33, and the jet ports of the first to third air inlet pipes 31 to 33 are respectively first to third jet ports 41 to 43, and the first to third jet ports 41 to 43 are respectively arranged close to the bottom area of ​​the reaction chamber 10, the middle area of ​​the reaction chamber 10, and the top area of ​​the reaction chamber 10 in the vertical direction.

[0066] At this time, introducing the first reaction gas into the reaction chamber 10 may include: controlling the gas flow rates of the first reaction gas introduced into the reaction chamber 10 from the first gas inlet pipe 31 to the third gas inlet pipe 33 to be respectively the first set gas flow rate, the second set gas flow rate, and the third set gas flow rate, wherein the first set gas flow rate is greater than the second set gas flow rate and the third set gas flow rate, so that the thickness deviation of the transition layer 203 is controlled within the first set range. Exemplarily, the ratio relationship between the first set gas flow rate, the second set gas flow rate, and the third set gas flow rate may be 3:2:2.

[0067] Next, refer to Figure 2C , perform the deposition step, and introduce Ge x H y The second reaction gas of the gas is used to deposit a germanium film layer 204 on the surface of the transition layer 203.

[0068] Regarding the type of the second reaction gas, it includes Ge x H y , so that it can be achieved through Ge x H y decomposes to deposit a germanium film 204 on the surface of the transition layer 203. Of course, the second reaction gas includes Ge x H y In addition to the gas, other reactive gases may also be included.

[0069] About Ge x H yThe type of gas, which can be of various types, for example, Ge x H y The gas may include GeH 4 Gas may also include other gases composed of germanium and hydrogen elements.

[0070] For example, the second reaction gas may also include B x Cl y Gas, the B x Cl y The B ions in the germanium film 204 are used to adjust the conductivity of the germanium film 204 to form a germanium film 204 that can bond with Al (aluminum). x Cl y The gas may include BCl 3 , thus BCl 3 The decomposition generates trivalent B ions to adjust the conductivity of the Ge film, forming a germanium film layer 204 that can bond with Al (aluminum).

[0071] When Ge x H y When the second reaction gas is used as the gas, the gas flow rate of the second reaction gas and the position of the gas inlet can be adjusted to improve the thickness uniformity and consistency of the deposited germanium film layer 204. There are many ways to do this.

[0072] Exemplary, reference Figure 4 A fourth air inlet pipe 34 and a fifth air inlet pipe 35 are also provided in the reaction chamber, and a plurality of fourth jet ports 44 are provided on the fourth air inlet pipe 34, and a plurality of fifth jet ports 45 are provided on the fifth air inlet pipe 35; the plurality of fourth jet ports 44 are distributed in the lower half of the reaction chamber 10 at intervals along the vertical direction, and the plurality of fifth jet ports 45 are distributed in the upper half of the reaction chamber 10 at intervals along the vertical direction.

[0073] At this time, Ge x H y The second reaction gas of the gas may include: the first gas inlet pipe 31 to the third gas inlet pipe 33 pass Ge into the reaction chamber 10 x H y The fourth air inlet pipe 34 and the fifth air inlet pipe 35 introduce B into the reaction chamber 10. x Cl yThe gas is provided in the first air inlet pipe 31 to the fifth air inlet pipe 35, and the gas flow rates of the first air inlet pipe 31 to the fifth air inlet pipe 35 are respectively the fourth set gas flow rate to the eighth set gas flow rate; wherein the fourth set gas flow rate is greater than the fifth set gas flow rate and the sixth set gas flow rate, and the fifth set gas flow rate and the sixth set gas flow rate are both greater than the seventh set gas flow rate and the eighth set gas flow rate, so that the thickness deviation of the germanium film layer 204 is controlled within the second set range. Exemplarily, the ratio between the fourth set gas flow rate to the eighth set gas flow rate can be 7:6:6:5:5.

[0074] Exemplary, reference Figure 2D The manufacturing method may further include: etching the germanium film layer 204 and the transition layer 203 to form a patterned germanium bonding layer 205. That is, after the germanium bonding layer 205 is formed on the semiconductor substrate 200 by the vapor phase chemical deposition process shown above, the formed germanium film layer 204 is further patterned to match the position and size of the germanium bonding layer 205 with the patterned aluminum bonding layer, so that the germanium bonding layer 205 can be bonded to the aluminum bonding layer.

[0075] Exemplarily, the germanium bonding layer 205 can be a germanium bonding ring layer, that is, the top view shape of the germanium bonding layer 205 is a ring. At this time, the germanium bonding layer 205 can be located in the edge area of ​​the semiconductor substrate 200, which surrounds the outside of the micromechanical structure and is spaced from the micromechanical structure.

[0076] Exemplary, reference Figure 2D The germanium bonding layer 205 formed by etching can be electrically connected to the plug in the device layer 202 to achieve functions such as but not limited to testing.

[0077] At this point, the process steps implemented in the method for manufacturing a MEMS device according to an embodiment of the present invention have been completed. It can be understood that the method for manufacturing a MEMS device in this embodiment not only includes the above steps, but may also include other necessary steps before, during or after the above steps, which are all included in the scope of the manufacturing method of this embodiment.

[0078] Embodiment 2

[0079] The present invention also provides a MEMS device, referring to Figure 3A The MEMS device mainly includes: a semiconductor substrate 300 and a germanium bonding layer 303, wherein the germanium bonding layer 303 is disposed on the semiconductor substrate 300 and is located at the edge region of the semiconductor substrate 300, and the germanium bonding layer 303 includes: a transition layer 304 and a germanium film layer 305 covering the transition layer 304, wherein the transition layer 304 is configured to promote Ge x H y break down.

[0080] Below, reference FIG. 3A to FIG. 3BThe MEMS device of the embodiment of the present invention is described in detail. It is worth mentioning that, in order to avoid repetition, only a brief description is given of the same components and structures as those in the aforementioned embodiment 1, and the specific explanation and description thereof can refer to the description in the embodiment 1.

[0081] Exemplary, reference Figure 3A The semiconductor substrate 300 includes a base 301 and a device layer 302 formed on the base 301 . A pad may also be formed on the semiconductor substrate 300 . The pad is electrically connected to the formed germanium bonding layer 303 through a plug and a metal wire in the device layer 302 .

[0082] Exemplary, reference Figure 3B A cap substrate 306 is also provided, and a metal bonding layer 307 is provided on the side of the cap substrate 306 facing the semiconductor substrate 300. The cap substrate 306 and the semiconductor substrate 300 are bonded to each other through the germanium bonding layer 303 and the metal bonding layer 307 to enclose a cavity between the semiconductor substrate 300 and the cap substrate 306 for accommodating or sealing the micromechanical structure.

[0083] Exemplarily, the metal bonding layer 307 may be an aluminum bonding layer, thereby achieving aluminum-germanium bonding between two semiconductor substrates.

[0084] Embodiment 3

[0085] Another embodiment of the present invention further provides a chemical vapor deposition device, referring to Figure 4 , the chemical vapor deposition device mainly includes:

[0086] A reaction chamber 10 extending in a vertical direction;

[0087] A wafer boat (not shown) disposed in the reaction chamber 10, the wafer boat being used to carry a plurality of semiconductor substrates 20 spaced apart in a vertical direction;

[0088] A driving mechanism (not shown in the figure) for driving the wafer boat to rotate along its vertical axis;

[0089] A pressure regulating device (not shown in the figure), used to adjust the pressure in the reaction chamber 10;

[0090] A temperature regulating device (not shown in the figure), used to regulate the temperature in the reaction chamber 10;

[0091] The air inlet pipe 30 is arranged in the reaction chamber 10, and the air inlet pipe 30 is distributed at intervals on the outside of the wafer boat along the circumference of the wafer boat:

[0092] The gas inlet pipe 30 is configured to: when performing the pre-deposition step, introduce the first reaction gas into the reaction chamber 10 to deposit a gas on the surface of the semiconductor substrate 20 that can promote Ge x Hy Decomposed transition layers; and,

[0093] When performing the deposition step, a gas including Ge is introduced into the reaction chamber 10. x H y A second reaction gas is used to deposit a germanium film layer on the surface of the transition layer.

[0094] The following is combined with Figure 4 Each of the above structures is introduced in detail.

[0095] The shape of the reaction chamber 10 may be, for example, but not limited to, a vertically arranged cylindrical shape. A plurality of accommodating brackets for placing semiconductor substrates 20 are arranged on the wafer boat, and the plurality of accommodating brackets are arranged in sequence along the vertical direction.

[0096] The driving mechanism for driving the wafer boat to rotate may include devices such as but not limited to motors and transmission mechanisms, which are used to drive the wafer boat to rotate along its vertical axis to drive the semiconductor substrate 20 placed thereon to rotate, thereby facilitating improvement of the thickness uniformity of the transition layer and germanium film layer deposited on the semiconductor substrate 20.

[0097] Regarding the setting of the temperature regulating device, it can adopt methods such as but not limited to electromagnetic heating, resistance wire heating, etc. to control the temperature in the reaction chamber 10. As described in the above method part, during the pre-deposition step, the temperature of the reaction chamber 10 can be adjusted to a set temperature by the temperature regulating device.

[0098] Regarding the setting of the pressure regulating device, it can use, for example but not limited to, a compressor to control the pressure in the reaction chamber 10. As described in the above method section, before the first reaction gas is introduced into the reaction chamber 10, the pressure of the reaction chamber 10 can be adjusted to be less than 10mt by the pressure regulating device.

[0099] Regarding the arrangement of the air inlet pipe 30, it is distributed on the outer side of the wafer boat along the circumference of the wafer boat, so as to introduce the first reaction gas and the second reaction gas into the reaction chamber 10 through the air inlet pipe 30. Some exemplary arrangements are introduced as follows.

[0100] A plurality of air inlet pipes 30 may be provided, and the gas flow distribution of the reaction gas in different air inlet pipes 30 may be reasonably adjusted according to the structural characteristics of the air jets on the different air inlet pipes 30, to ensure that the problem of uneven thickness between sheets caused by uneven gas flow or uneven gas flow ratio is avoided.

[0101] Exemplarily, the air intake pipe 30 may include: a first air intake pipe 31, a second air intake pipe 32 and a third air intake pipe 33. The first air intake pipe 31 to the third air intake pipe 33 are respectively provided with first to third air intake ports 41 to 43, that is, the first air intake pipe 31 is provided with the first air intake port 41, the second air intake pipe 32 is provided with the second air intake port 42, and the third air intake pipe 33 is provided with the third air intake port 43. For example, the first air intake pipe 31 to the third air intake pipe 33 are provided with only one air intake port at the end position.

[0102] The first to third gas jets 41 to 43 are respectively arranged near the bottom area of ​​the reaction chamber 10, the middle area of ​​the wafer boat, and the top area of ​​the wafer boat in the vertical direction. Specifically, the first gas jet 41 is arranged near the bottom area of ​​the reaction chamber 10, and the gas ejected therefrom passes through all the semiconductor substrates 20 on the wafer boat and is discharged from the top of the reaction chamber 10. The second gas jet 42 is arranged in the middle area of ​​the wafer boat, and the gas ejected therefrom passes through some of the semiconductor substrates 20 on the wafer boat and is discharged from the top of the reaction chamber 10. The third gas jet 43 is arranged in the top area of ​​the wafer boat, and the gas ejected therefrom passes through a few semiconductor substrates 20 on the wafer boat and is discharged from the top of the reaction chamber 10. Thus, the gas flow rate of the reaction gas introduced into different areas of the reaction chamber 10 can be controlled by controlling the gas flow rate in different gas inlet pipes 30, so as to improve the thickness uniformity and consistency of the deposited transition layer or germanium film layer.

[0103] Exemplarily, the first gas inlet pipe 31 to the third gas inlet pipe 33 are configured such that: when performing the pre-deposition step, the gas flow rates of the first reaction gas introduced into the reaction chamber 10 by the first gas inlet pipe 31 to the third gas inlet pipe 33 are respectively the first set gas flow rate, the second set gas flow rate and the third set gas flow rate. The first set gas flow rate may be greater than the second set gas flow rate and the third set gas flow rate, so that the thickness deviation of the transition layer is controlled within the first set range.

[0104] Since the first jet port 41, the second jet port 42 and the third jet port 43 are arranged in sequence from upstream to downstream in the direction of the gas flow, when the first set gas flow rate is set to be greater than the second set gas flow rate and the third set gas flow rate, it is beneficial to balance the total amount of gas that contacts the first reaction gas with the semiconductor substrates 20 in different areas of the wafer boat, and it is beneficial to make the thickness of the transition layer deposited on the semiconductor substrate 20 at different positions uniform, thereby helping to improve the consistency of the thickness of the transition layer between wafers.

[0105] It should be noted that the thickness deviation of the transition layer refers to the difference between the actual thickness of the transition layer at each location and the standard thickness, which is controlled within a first set range, so that the thickness of the transition layer on different semiconductor substrates 20 and the thickness of the transition layer at different locations on the same semiconductor substrate 20 can be maintained near the standard thickness, which is beneficial to improving the thickness uniformity and consistency of the transition layer.

[0106] Regarding the method for determining the first set airflow rate, the second set airflow rate and the third set airflow rate, it can be based on the hardware settings of the same chemical vapor deposition device, the number of semiconductor substrates 20, etc., and after multiple tests, the appropriate airflow rates of different inlet pipes 30 can be obtained to determine the proportional relationship between the first set airflow rate, the second set airflow rate and the third set airflow rate.

[0107] Exemplarily, the ratio between the first set air flow rate, the second set air flow rate and the third set air flow rate can be a plurality of ratios. Exemplarily, the ratio between the first set air flow rate and the third set air flow rate is 3:2:2. By adopting this ratio, the thickness uniformity and consistency of the transition layer can be improved.

[0108] Exemplarily, as described in the above method section, in some embodiments, the second reaction gas includes Ge x H y and B x Cl y Gas, corresponding to this, this embodiment further provides some additional air intake pipes 30.

[0109] Exemplarily, the air inlet pipe 30 further includes: a fourth air inlet pipe 34 and a fifth air inlet pipe 35. The fourth air inlet pipe 34 is provided with a plurality of fourth air jets 44, and the fifth air inlet pipe 35 is provided with a plurality of fifth air jets 45; the plurality of fourth air jets 44 are distributed in the lower half of the reaction chamber 10 at intervals along the vertical direction, and the plurality of fifth air jets 45 are distributed in the upper half of the reaction chamber 10 at intervals along the vertical direction. Specifically, a plurality of fourth air jets 44 are provided on the side wall of the fourth air inlet pipe 34, and a plurality of fifth air jets 45 are provided on the fifth air inlet pipe 35. Due to the introduction of the plurality of fourth air jets 44 and the plurality of fifth air jets 45, the balance of the gas in the reaction chamber 10 is improved, which is beneficial to the thickness uniformity of the germanium film layer.

[0110] The fourth air inlet pipe 34 and the fifth air inlet pipe 35 are mainly used to introduce B into the reaction chamber 10 during the step of depositing the germanium film. x Cl y The first gas inlet pipe 31 to the third gas inlet pipe 33 can also be used to introduce Ge into the reaction chamber 10 in the step of depositing a germanium film layer. x H y Thus, the two types of gases introduced through the first gas inlet pipe 31 to the fifth gas inlet pipe 35 are mixed and reacted to form a germanium film layer that can be bonded to the aluminum bonding layer.

[0111] Exemplarily, the first air inlet pipe 31 to the fifth air inlet pipe 35 are configured as follows: when performing the deposition step, the first air inlet pipe 31 to the third air inlet pipe 33 introduce Ge into the reaction chamber 10. x Hy The fourth air inlet pipe 34 and the fifth air inlet pipe 35 introduce B into the reaction chamber 10. x Cl y The gas is used for the first and second reaction gases, and the gas flow rates of the first gas inlet pipe 31 to the fifth gas inlet pipe 35 are respectively the fourth set gas flow rate to the eighth set gas flow rate. The fourth set gas flow rate is greater than the fifth set gas flow rate and the sixth set gas flow rate, and the fifth set gas flow rate and the sixth set gas flow rate are both greater than the seventh set gas flow rate and the eighth set gas flow rate, so that the thickness deviation of the germanium film layer is controlled within the second set range. This method is conducive to balancing the total gas volume contacted by the semiconductor substrate 20 in different regions of the wafer boat with the second reaction gas, and is conducive to uniform thickness of the germanium film layer deposited on the semiconductor substrate 20 at different positions, thereby facilitating the improvement of the consistency of the thickness of the germanium film layer between wafers.

[0112] It should be noted that the thickness deviation of the germanium film layer refers to the difference between the actual thickness of the germanium film layer at various locations and the standard thickness, which is controlled within the second set range, so that the thickness of the germanium film layer on different semiconductor substrates 20 and the germanium film layer at different positions on the same semiconductor substrate 20 can be kept near the standard thickness, which is beneficial to improving the thickness uniformity and consistency of the germanium film layer.

[0113] Regarding the method for determining the fourth set airflow rate to the eighth set airflow rate, it can be based on the hardware settings of the same chemical vapor deposition device, the number of semiconductor substrates 20, etc., and after multiple tests, the appropriate airflow rate of different inlet pipes 30 can be obtained to determine the proportional relationship between the fourth set airflow rate to the eighth set airflow rate.

[0114] Exemplarily, the ratio between the fourth set gas flow rate to the eighth set gas flow rate may be 7:6:6:5:5. By adopting this ratio, the thickness uniformity and consistency of the germanium film layer can be improved.

[0115] It should be noted that various types of nozzles may be provided at the above-mentioned air jet ports to increase the free path of the gas, thereby improving the thickness uniformity of the transition layer and the germanium film layer.

[0116] Exemplarily, the gas flow ratio of the overall reaction gas can be adjusted to compensate for the color difference caused by the number of semiconductor substrates 20 or the proportion of bare silicon on the semiconductor substrate 20. To verify the rationality of the gas flow ratio, a semiconductor substrate 20 that is all bare silicon and a semiconductor substrate 20 with a device area can be used to deposit a germanium film using the above method and apparatus at the same time, and then observe whether there is color difference on the surface of the semiconductor substrate 20 with the device area to verify whether the gas flow ratio is reasonable.

[0117] In the process of adjusting the air flow rates in different intake pipes 30 , multiple adjustments may be performed to determine the above-mentioned appropriate first set air flow rate to eighth set air flow rate.

[0118] refer to Figure 5 , through PI run test data, it can meet the design requirements. As of now, 35% of the products have used the improved pre-deposition process to prepare the germanium film layer.

[0119] Embodiment 4

[0120] Another embodiment of the present invention provides an electronic device, which includes the aforementioned MEMS device, and the MEMS device is manufactured according to the aforementioned method.

[0121] The electronic device of this embodiment can be any electronic product or device such as a mobile phone, a tablet computer, a laptop computer, a netbook, a game console, a television, a VCD, a DVD, a navigator, a digital photo frame, a camera, a video camera, a voice recorder, an MP3, an MP4, a PSP, etc., or any intermediate product including a circuit. The electronic device of the embodiment of the present invention has better performance due to the use of the above-mentioned MEMS device.

[0122] The present invention has been described by the above embodiments, but it should be understood that the above embodiments are only for the purpose of example and description, and are not intended to limit the present invention to the scope of the described embodiments. In addition, it can be understood by those skilled in the art that the present invention is not limited to the above embodiments, and more variations and modifications can be made according to the teachings of the present invention, and these variations and modifications all fall within the scope of the protection claimed by the present invention. The protection scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for manufacturing a MEMS device, characterized in that: include: Providing a semiconductor substrate, and placing the semiconductor substrate in a reaction chamber; Perform a pre-deposition step, introduce a first reaction gas into the reaction chamber to deposit a gas on the surface of the semiconductor substrate that can promote Ge x H y Decomposed transition layer; Perform a deposition step, introduce Ge into the reaction chamber x H y A second reaction gas of the gas is used to deposit a germanium film layer on the surface of the transition layer.

2. The manufacturing method according to claim 1, characterized in that The transition layer includes an amorphous silicon film layer, and the first reaction gas includes Si x H y gas.

3. The manufacturing method according to claim 1, characterized in that: Also includes: Before the first reaction gas is introduced into the reaction chamber, the pressure in the reaction chamber is adjusted to less than 10 mt.

4. The manufacturing method according to claim 1, characterized in that: The thickness of the transition layer is less than 5. The manufacturing method according to claim 1, characterized in that: Also includes: The germanium film layer and the transition layer are etched to form a patterned germanium bonding layer.

6. A MEMS device, characterized in that: include: Semiconductor substrate; A germanium bonding layer is disposed on the semiconductor substrate and is located at an edge region of the semiconductor substrate, wherein the germanium bonding layer includes a transition layer and a germanium film layer covering the transition layer, and the transition layer is configured to promote Ge x H y break down.

7. The MEMS device according to claim 6, characterized in that Also includes: A cap substrate is provided with a metal bonding layer on a side of the cap substrate facing the semiconductor substrate, and the cap substrate and the semiconductor substrate are bonded to each other through the germanium bonding layer and the metal bonding layer.

8. A chemical vapor deposition device, characterized in that: include: A reaction chamber extending in a vertical direction; A wafer boat is arranged in the reaction chamber, and the wafer boat is used to carry a plurality of semiconductor substrates arranged at intervals in a vertical direction; A driving mechanism for driving the wafer boat to rotate along its vertical axis; A pressure regulating device, used to adjust the pressure in the reaction chamber; A temperature regulating device, used to regulate the temperature in the reaction chamber; An air inlet pipe is arranged in the reaction chamber, and the air inlet pipe is distributed at intervals on the outside of the wafer boat along the circumference of the wafer boat; The gas inlet pipe is configured to: when performing the pre-deposition step, introduce the first reaction gas into the reaction chamber to deposit a gas on the surface of the semiconductor substrate that can promote Ge x H y Decomposed transition layer; as well as, When performing the deposition step, a gas including Ge is introduced into the reaction chamber. x H y A second reaction gas is added to deposit a germanium film layer on the surface of the transition layer.

9. The chemical vapor deposition apparatus according to claim 8, characterized in that: The air inlet pipe includes: a first air inlet pipe, a second air inlet pipe and a third air inlet pipe; wherein the first air inlet pipe to the third air inlet pipe are respectively provided with a first air jet port to a third air jet port, and the first air jet port to the third air jet port are respectively provided close to the bottom area of ​​the reaction chamber in the vertical direction, the middle area of ​​the wafer boat, and the top area of ​​the wafer boat; The first air inlet pipe to the third air inlet pipe are configured as follows: when performing the pre-deposition step, the gas flow rates of the first reaction gas introduced into the reaction chamber by the first air inlet pipe to the third air inlet pipe are respectively the first set gas flow rate, the second set gas flow rate and the third set gas flow rate; wherein the first set gas flow rate is greater than the second set gas flow rate and the third set gas flow rate, so that the thickness deviation of the transition layer is controlled within a first set range.

10. The chemical vapor deposition apparatus according to claim 9, characterized in that: The air intake pipe further includes: a fourth air intake pipe and a fifth air intake pipe; wherein the fourth air intake pipe is provided with a plurality of fourth air injection ports, and the fifth air intake pipe is provided with a plurality of fifth air injection ports; the plurality of fourth air injection ports are distributed in a lower half of the reaction chamber at intervals along the vertical direction, and the plurality of fifth air injection ports are distributed in an upper half of the reaction chamber at intervals along the vertical direction; The second reaction gas includes Ge x H y and B x Cl y gas; The first to the fifth air inlet pipes are configured such that when performing a deposition step, the first to the third air inlet pipes introduce Ge into the reaction chamber. x H y The fourth air inlet pipe and the fifth air inlet pipe introduce B into the reaction chamber. x Cl y Gas, and the gas flow rates from the first gas inlet pipe to the fifth gas inlet pipe are respectively the fourth set gas flow rate to the eighth set gas flow rate; wherein, the fourth set gas flow rate is greater than the fifth set gas flow rate and the sixth set gas flow rate, and the fifth set gas flow rate and the sixth set gas flow rate are both greater than the seventh set gas flow rate and the eighth set gas flow rate, so that the thickness deviation of the germanium film layer is controlled within the second set range.

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