A method for manufacturing a micro-coaxial structure

Abstract

The application discloses a preparation method of a micro coaxial structure, which comprises the following steps: forming a first groove on a substrate; forming a partial micro coaxial structure in the first groove, wherein a sacrifice layer is deposited in the first groove for forming the partial micro coaxial structure, and the sacrifice layer fills the first groove; and preparing a remaining micro coaxial structure on the partial micro coaxial structure. The application forms a groove on a substrate, adopts a deposition process to replace part of a photoetching process, thereby simplifying the photoetching process, and making the obtained micro coaxial structure more stable.

Description

Technical Field

[0001] This invention relates to the field of metal microstructure manufacturing technology, and in particular to a method for preparing a micro-coaxial structure. Background Technology

[0002] Existing methods for fabricating microcoaxial structures generally involve repeated cycles of thick photolithography, seed layer deposition, copper electroplating, and Cu-CMP. The photolithography process is repeated at least seven times. This method, involving multi-layer photolithography, electroplating, and CMP, is cumbersome and not concise. Furthermore, the multiple photolithography steps result in unstable microcoaxial structures. Summary of the Invention

[0003] This application provides a method for fabricating a microcoaxial structure by using a deposition process to replace part of the photolithography process, thereby simplifying the photolithography process and resulting in a more stable microcoaxial structure.

[0004] In a first aspect, the present invention provides the following technical solution through an embodiment of the present invention:

[0005] A method for fabricating a microcoaxial structure includes: forming a first groove on a substrate; forming a partial microcoaxial structure within the first groove, wherein a sacrificial layer is deposited within the first groove forming the partial microcoaxial structure, the sacrificial layer filling the first groove; and fabricating a remaining microcoaxial structure on the partial microcoaxial structure.

[0006] Preferably, forming a partial microcoaxial structure within the first groove includes: forming a microcoaxial bottom layer, a first partial microcoaxial sidewall, and a support layer within the first groove; and fabricating a remaining microcoaxial structure on the partial microcoaxial structure includes: fabricating a second partial microcoaxial sidewall on the first partial microcoaxial sidewall and fabricating an inner shaft on the support layer; and fabricating a microcoaxial top layer on the second partial microcoaxial sidewall.

[0007] Preferably, the first groove includes an edge and a center. The step of forming a micro-coaxial underlayer, a first portion of micro-coaxial sidewalls, and a support layer in the first groove includes: depositing the micro-coaxial underlayer and the first portion of micro-coaxial sidewalls in the first groove; depositing a sacrificial layer in the deposited first groove to fill the first groove; etching a second groove in the center of the filled first groove, and depositing a support layer in the second groove.

[0008] Preferably, the depth-to-width ratio of the first groove is 2:5.

[0009] Preferably, the depth-to-width ratio of the second groove is 1:1.

[0010] Preferably, the second part of the micro-coaxial sidewall includes a copper axis layer 2 and a copper axis layer 3. The step of fabricating the second part of the micro-coaxial sidewall on the first part of the micro-coaxial sidewall and fabricating the inner axis on the support layer includes: fabricating the copper axis layer 2 on the first part of the micro-coaxial sidewall and fabricating the inner axis on the support layer; removing photoresist and depositing a sacrificial layer to fill the copper axis layer 2; fabricating the copper axis layer 3 on the copper axis layer 2; removing photoresist and depositing a sacrificial layer to fill the copper axis layer 3.

[0011] Preferably, the process of preparing the second part of the microcoaxial sidewall and the microcoaxial top layer includes: forming a release hole in the microcoaxial top layer and / or the second part of the microcoaxial sidewall.

[0012] Preferably, forming a partial microcoaxial structure in the first groove further includes: forming a microcoaxial bottom layer, a first partial microcoaxial sidewall, a support layer, and an inner shaft in the first groove; and fabricating a remaining microcoaxial structure on the partial microcoaxial structure includes: fabricating a second partial microcoaxial sidewall on the first partial microcoaxial sidewall; and fabricating a microcoaxial top layer on the second partial microcoaxial sidewall.

[0013] Preferably, forming a microcoaxial underlayer, a first portion of the microcoaxial sidewall, a support layer, and an inner shaft within the first groove includes: depositing the microcoaxial underlayer and the first portion of the microcoaxial sidewall within the first groove; depositing a sacrificial layer within the deposited first groove to fill the first groove; etching a second groove in the center of the filled first groove and depositing a support layer within the second groove; and depositing the inner shaft above the support layer.

[0014] Preferably, forming a partial microcoaxial structure in the first groove further includes: forming a microcoaxial bottom layer, a microcoaxial sidewall, a support layer, and an inner shaft in the first groove; and fabricating a remaining microcoaxial structure on the partial microcoaxial structure includes: fabricating a microcoaxial top layer on the microcoaxial sidewall.

[0015] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0016] This invention provides a method for fabricating a microcoaxial structure. First, a first groove is formed on a substrate. Then, a partial microcoaxial structure is formed within the first groove. A sacrificial layer is deposited within the first groove to fill the groove. The remaining microcoaxial structure is then fabricated on top of the partial microcoaxial structure. This method replaces the traditional photolithography process for fabricating microcoaxial structures with a method that first forms a groove on the substrate and then deposits the partial microcoaxial structure within the groove. This simplifies the photolithography process and effectively improves upon the cumbersome photolithography involved in traditional microcoaxial fabrication methods. It avoids the instability of the microcoaxial structure caused by the complex photolithography process, resulting in a more stable microcoaxial structure. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A flowchart illustrating a method for fabricating a micro-coaxial structure according to an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of a micro-coaxial structure provided in an embodiment of the present invention. Detailed Implementation

[0020] This application provides a method for fabricating a microcoaxial structure by using a deposition process to replace part of the photolithography process, thereby simplifying the photolithography process and resulting in a more stable microcoaxial structure.

[0021] The overall technical solution of this application embodiment is as follows:

[0022] A method for fabricating a microcoaxial structure includes: forming a first groove on a substrate; forming a partial microcoaxial structure within the first groove, wherein a sacrificial layer is deposited within the first groove forming the partial microcoaxial structure, the sacrificial layer filling the first groove; and fabricating a remaining microcoaxial structure on the partial microcoaxial structure.

[0023] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0024] Firstly, the present invention provides a method for preparing a micro-coaxial structure, specifically, as follows: Figure 1 As shown, the preparation method includes the following steps S101 to S104.

[0025] Step S101: Form a first groove on the substrate;

[0026] Step S102: A partial micro-coaxial structure is formed in the first groove, wherein a sacrificial layer is deposited in the first groove in which the partial micro-coaxial structure is formed, and the sacrificial layer fills the first groove.

[0027] Step S103: On the partially microcoaxial structure, the remaining microcoaxial structure is prepared.

[0028] In the specific implementation process, a dry etching method can be used to form the first groove 102 on the substrate 100. The substrate 100 can be a silicon substrate or other commonly used semiconductor substrates, and this application does not impose any restrictions.

[0029] As an optional embodiment, forming a partial microcoaxial structure within the first groove may include: forming a microcoaxial bottom layer, a first partial microcoaxial sidewall, and a support layer within the first groove; and fabricating a remaining microcoaxial structure on the partial microcoaxial structure may include: fabricating a second partial microcoaxial sidewall on the first partial microcoaxial sidewall and fabricating an inner shaft on the support layer; and fabricating a microcoaxial top layer on the second partial microcoaxial sidewall.

[0030] like Figure 2 As shown, the microcoaxial substrate 101 includes a barrier layer, an adhesive layer, etc., and the first part of the microcoaxial sidewall can be a copper shaft layer 103. The first groove 102 includes an edge and a center. The microcoaxial substrate 101, the first part of the microcoaxial sidewall, and the support layer 104 are formed in the first groove 102. Specifically, it can include: depositing the microcoaxial substrate 101 and the first part of the microcoaxial sidewall in the first groove 102; depositing a sacrificial layer in the deposited first groove 102 until it is filled; etching a second groove in the center of the filled first groove 102, and depositing the support layer 104 in the second groove. The first part of the microcoaxial sidewall and the support layer are at the same height as the upper surface of the substrate. The center of the first groove is the location where the support layer of the microcoaxial structure is formed.

[0031] Specifically, a barrier layer, an adhesive layer, and a copper shaft layer 103 of a certain thickness are deposited in the first groove 102. A sacrificial layer of a certain thickness is then deposited in the first groove 102 to fill the groove. A second groove of a certain size is formed in the first groove 102 using dry etching. This second groove is located in the center of the first groove 102. A support layer 104 is deposited in the second groove. Then, the formed support layer 104, the first portion of the micro-coaxial sidewalls, and the sacrificial layer are subjected to chemical mechanical polishing (CMP).

[0032] It should be noted that the dimensions of the first and second grooves can be determined based on the target performance requirements and design simulations. For example, in one application scenario, the aspect ratio of the first groove 102 can be 2:5, and the aspect ratio of the second groove can be 1:1.

[0033] In a specific embodiment, the second part of the micro-coaxial sidewall includes a copper axis layer 113 and a copper axis layer 114. To make the alignment of the micro-coaxial sidewall more accurate and to facilitate the subsequent release of the sacrificial layer, the second part of the micro-coaxial sidewall is fabricated on the first part of the micro-coaxial sidewall, and an inner axis 105 is fabricated on the support layer 104. Specifically, this may include: fabricating a copper axis layer 113 on the first part of the micro-coaxial sidewall and fabricating an inner axis 105 on the support layer 104; removing photoresist and depositing a sacrificial layer to fill the copper axis layer 113; fabricating a copper axis layer 114 on the copper axis layer 113; removing photoresist and depositing a sacrificial layer to fill the copper axis layer 114.

[0034] Specifically, a copper axis second layer 113 is fabricated on the leveled substrate (i.e., on the first part of the micro-coaxial sidewall) using photolithography and copper plating processes. Then, the photoresist is removed, and after removal, a sacrificial layer of a certain thickness is deposited onto the leveled copper axis second layer 113, followed by chemical mechanical polishing. Next, a copper axis third layer 114 is fabricated on the leveled substrate (i.e., on the copper axis second layer 113) using photolithography and copper plating processes. Then, the photoresist is removed, and after removal, a sacrificial layer of a certain thickness is deposited onto the leveled copper axis third layer 114, followed by chemical mechanical polishing.

[0035] That is, after depositing the sacrificial layer to fill the second copper shaft layer 113, the second copper shaft layer 113 needs to be chemically and mechanically polished, and after depositing the sacrificial layer to fill the third copper shaft layer 114, the third copper shaft layer 114 needs to be chemically and mechanically polished, so as to achieve global planarization.

[0036] It should be noted that traditional photolithography typically does not remove the photoresist directly after completion. Instead, it is used as a final sacrificial layer and accumulated layer by layer. After the gradual deposition of multiple copper layers, all the photoresist is released to complete the fabrication of the micro-coaxial structure. Using a method of accumulating thick photoresist layer by layer, multiple exposures not only increase the difficulty of alignment, but also, during the accumulation of thick photoresist, it undergoes various changes in the microenvironment of different processes (such as high-temperature microenvironment, acid or alkaline solution microenvironment, CVD or PVD dry ion bombardment microenvironment, etc.), which brings certain difficulties to the final removal process.

[0037] This application adopts a method of directly removing photoresist after photolithography, which allows each sacrificial layer to be of the same type, making it easier to remove the sacrificial layer. Furthermore, directly removing the photoresist can avoid the accumulation of photoresist layer by layer, resulting in higher alignment accuracy of the copper axis and higher stability of the obtained micro-coaxial structure.

[0038] A microcoaxial top layer 106 is fabricated on the second part of the microcoaxial sidewall. In a specific embodiment, the microcoaxial top layer 106 is fabricated on the leveled substrate (i.e., on the second part of the microcoaxial sidewall) by photolithography and copper electroplating, and the microcoaxial top layer 106 is subjected to chemical mechanical polishing.

[0039] In order to release the sacrificial layer formed during the aforementioned preparation process, the process of preparing the second part of the microcoaxial sidewall and the microcoaxial top layer 106 includes: forming a release hole in the microcoaxial top layer 106 and / or the second part of the microcoaxial sidewall to remove the sacrificial layer filled in the microcoaxial sidewall through the release hole.

[0040] Specifically, a release hole can be formed in the top layer 106 of the microcoaxial cable, penetrating the top layer 106, to remove the sacrificial layer filling the sidewalls of the microcoaxial cable. Alternatively, a release hole can be formed in the second part of the microcoaxial sidewall; the sacrificial layer filling the sidewalls of the microcoaxial cable can be removed through the release hole. Alternatively, a release hole can be formed in both the top layer 106 of the microcoaxial cable and the second part of the microcoaxial sidewall; the sacrificial layer filling the sidewalls of the microcoaxial cable can be removed through the release hole.

[0041] For example, in one application scenario, a design was created based on the performance of the micro-coaxial structure, such as... Figure 2 The two types of release hole structures shown are: the first type has a first release hole 107, a second release hole 108 and a third release hole 109 formed on the sidewall of the micro coaxial structure; the second type has a fourth release hole 110, a fifth release hole 111 and a sixth release hole 112 formed on the top layer 106 of the micro coaxial structure.

[0042] As another optional embodiment, forming a partial microcoaxial structure within the first groove 102 may further include: forming a microcoaxial bottom layer 101, a first partial microcoaxial sidewall, a support layer 104, and an inner shaft 105 within the first groove 102; and fabricating a remaining microcoaxial structure on the partial microcoaxial structure, including: fabricating a second partial microcoaxial sidewall on the first partial microcoaxial sidewall; and fabricating a microcoaxial top layer 106 on the second partial microcoaxial sidewall.

[0043] In a specific embodiment, a micro-coaxial underlayer 101, a first portion of micro-coaxial sidewalls, a copper shaft layer 1 and a copper shaft layer 2 equiaxial sidewalls, a support layer 104, and an inner shaft 105 are formed within the first groove 102. The first portion of the micro-coaxial sidewalls includes a copper shaft layer 103 and a copper shaft layer 2 113. This process may include: depositing the micro-coaxial underlayer 101 and the first portion of the micro-coaxial sidewalls within the first groove 102; depositing a sacrificial layer within the deposited first groove 102 until it is filled; etching a second groove in the center of the filled first groove 102 and depositing a support layer 104 within the second groove; and depositing an inner shaft 105 above the support layer 104 until it is flush with the first groove 102. The dimensions of the first groove 102 and the second groove will be determined according to the target performance requirements and design simulation needs.

[0044] The second part of the microcoaxial sidewall includes a copper-axis three-layer 114. The second part of the microcoaxial sidewall is fabricated on the first part of the microcoaxial sidewall, including: fabricating the copper-axis three-layer 114 on the first part of the microcoaxial sidewall; removing the photoresist and depositing a sacrificial layer to fill the copper-axis three-layer 114; then fabricating a microcoaxial top layer 106, and after removing the photoresist, depositing a sacrificial layer of a certain thickness to fill the microcoaxial top layer 106, followed by chemical mechanical polishing.

[0045] As another optional embodiment, forming a partial microcoaxial structure in the first groove 102 may further include: forming a microcoaxial bottom layer 101, a microcoaxial sidewall, a support layer 104, and an inner shaft 105 in the first groove 102. The process of preparing a remaining microcoaxial structure on the partial microcoaxial structure includes: preparing a microcoaxial top layer 106 on the microcoaxial sidewall.

[0046] In a specific embodiment, a microcoaxial underlayer 101, a first portion of microcoaxial sidewalls, a support layer 104, and an inner shaft 105 are formed within the first groove 102. The first portion of the microcoaxial sidewalls includes a copper shaft layer 103, a copper shaft layer 113, and a copper shaft layer 114. This process may include: depositing the microcoaxial underlayer 101 and the first portion of the microcoaxial sidewalls within the first groove 102; depositing a sacrificial layer within the deposited first groove 102 to fill it; etching a second groove in the center of the filled first groove 102 and depositing a support layer 104 within the second groove; depositing an inner shaft 105 above the support layer 104, and depositing a sacrificial layer on the inner shaft 105 until it is flush with the first groove 102 to fill the second groove. The dimensions of the first groove 102 and the second groove will be determined according to the target performance requirements and design simulation needs.

[0047] Therefore, the fabrication method of the micro-coaxial structure proposed in this application can effectively improve the problems of complicated photolithography process and difficulty in removing the sacrificial layer in the fabrication method of micro-coaxial structure. The fabrication method proposed in this application is a fabrication method that simplifies photolithography and makes it easy to release the sacrificial layer.

[0048] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0049] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for preparing a micro-coaxial structure, characterized in that, include: A first groove is formed on the substrate; A partial microcoaxial structure is formed in the first groove, wherein a sacrificial layer is deposited in the first groove forming the partial microcoaxial structure, and the sacrificial layer fills the first groove. The remaining microcoaxial structure is fabricated on the partially microcoaxial structure; The process of forming a partial micro-coaxial structure within the first groove further includes: A micro-coaxial bottom layer, a first partial micro-coaxial sidewall, a support layer, and an inner shaft are formed within the first groove. The remaining micro-coaxial structure is then fabricated on the partial micro-coaxial structure, including: A second microcoaxial sidewall is fabricated on the first microcoaxial sidewall; A micro-coaxial top layer is fabricated on the second part of the micro-coaxial sidewall; The process of forming a micro-coaxial bottom layer, a first portion of the micro-coaxial sidewall, a support layer, and an inner shaft within the first groove includes: The microcoaxial substrate and the first portion of the microcoaxial sidewall are deposited within the first groove; Deposit a sacrificial layer in the first groove after deposition until the first groove is filled; A second groove is etched in the middle of the first groove after it has been filled, and a support layer is deposited in the second groove; the inner shaft is deposited on top of the support layer.

2. The preparation method according to claim 1, characterized in that, The formation of a partial micro-coaxial structure within the first groove includes: A micro-coaxial bottom layer, a first partial micro-coaxial sidewall, and a support layer are formed within the first groove. The remaining micro-coaxial structure is then fabricated on the partial micro-coaxial structure, including: A second microcoaxial sidewall is fabricated on the first microcoaxial sidewall, and an inner shaft is fabricated on the support layer; A microcoaxial top layer is prepared on the second part of the microcoaxial sidewall.

3. The preparation method according to claim 2, characterized in that, The first groove includes an edge and a center. The formation of a micro-coaxial bottom layer, a first portion of micro-coaxial sidewalls, and a support layer within the first groove includes: The microcoaxial substrate and the first portion of the microcoaxial sidewall are deposited within the first groove; Deposit a sacrificial layer in the first groove after deposition until the first groove is filled; A second groove is etched in the middle of the filled first groove, and a support layer is deposited in the second groove.

4. The preparation method according to claim 3, characterized in that, The depth-to-width ratio of the first groove is 2:

5.

5. The preparation method according to claim 3, characterized in that, The depth-to-width ratio of the second groove is 1:

1.

6. The preparation method according to claim 2, characterized in that, The second part of the micro-coaxial sidewall includes a copper shaft layer 2 and a copper shaft layer 3. The process of fabricating the second part of the micro-coaxial sidewall on the first part of the micro-coaxial sidewall, and fabricating the inner shaft on the support layer, includes: The copper shaft double layer is fabricated on the first part of the micro coaxial sidewall, and the inner shaft is fabricated on the support layer; Remove the light resist and deposit a sacrificial layer to fill the copper shaft layer; The third layer of copper shaft is fabricated on the second layer of copper shaft; Remove the photoresist and deposit a sacrificial layer to fill the copper shaft triple layer.

7. The preparation method according to claim 2, characterized in that, The process of fabricating the second portion of the micro-coaxial sidewall and the micro-coaxial top layer includes: Release holes are formed in the top layer of the microcoaxial structure and / or the sidewall of the second portion of the microcoaxial structure.

8. The preparation method according to claim 1, characterized in that, The process of forming a partial micro-coaxial structure within the first groove further includes: A microcoaxial bottom layer, a microcoaxial sidewall, a support layer, and an inner shaft are formed within the first groove. The remaining microcoaxial structure is then fabricated on the partial microcoaxial structure, including: A microcoaxial top layer is prepared on the microcoaxial sidewall.

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