Metal pattern generation method and system based on stripping method

Abstract

The invention provides a metal pattern generation method and system based on a stripping method, and the method comprises the steps: carrying out the soft baking of a substrate coated with a positive photoresist, and placing a mask plate on the positive photoresist, so as to form a mask region and a non-mask region on the positive photoresist; exposing the material on which the mask plate is placed by using an exposure machine to obtain a first substrate structure; the first substrate structure is put into an oven filled with preset gas to be baked, and a second substrate structure is obtained; performing full exposure on the second substrate structure by using an exposure machine, so that a photo-acid region is formed in a non-neutralized region on the second substrate structure, and a third substrate structure is obtained; developing the third substrate structure by using a developing solution to form an undercut structure on the third substrate structure to obtain a fourth substrate structure; and carrying out metal film deposition on the fourth substrate structure by utilizing a physical vapor deposition method, and carrying out positive photoresist dissolution by utilizing the photoresist removing solution, so that a metal pattern is formed on the fourth substrate structure.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a metal pattern generation method based on a lift-off method and a system thereof. Background Art

[0002] With the rapid development of science and technology and the improvement of people's living standards, semiconductor products have become an indispensable part of people's lives.

[0003] At present, the stripping method for metal patterns on substrates adopts a double-layer method, which uses two photoresists to perform photolithography patterns and forms corresponding photoresist profiles by controlling the development time of the two photoresists respectively, thereby achieving metal stripping. However, this method requires the use of two special photoresists, which are relatively expensive, and the metal deposited by the double-layer method requires more steps to be separated, making the processing more cumbersome and the working time longer. Summary of the invention

[0004] Based on this, an object of the present invention is to provide a metal pattern generation method based on a lift-off method and a system thereof, so as to at least solve the deficiencies in the above-mentioned technology.

[0005] The present invention provides a method for generating a metal pattern based on a lift-off method, comprising: Coating a positive photoresist on a preset substrate, soft-baking the positive photoresist, and then placing a mask plate on the positive photoresist to form a mask area and a non-mask area on the positive photoresist; Using an exposure machine to expose the material after the mask plate is placed, so that a photoacid region is formed on the non-mask region to obtain a first substrate structure; The first substrate structure is placed in an oven filled with a preset gas for baking, so that the photoacid region on the first substrate structure is neutralized to obtain a second substrate structure; Fully exposing the second substrate structure by using the exposure machine, so that the non-neutralized area on the second substrate structure forms a photoacid area, thereby obtaining a third substrate structure; developing the third substrate structure with a developer to form an undercut structure on the third substrate structure to obtain a fourth substrate structure; A metal film is deposited on the fourth substrate structure by using a physical vapor deposition method, and a photoresist removal solution is used to dissolve the positive photoresist, so as to form a metal pattern on the fourth substrate structure.

[0006] Furthermore, the thickness of the positive photoresist coated on the preset substrate is 0.8 μm-10 μm, the soft baking temperature is 80° C.-110° C., and the rotation speed is 2500 rpm-4000 rpm.

[0007] Furthermore, the exposure energy and total exposure energy of the exposure machine are both 5000mJ~10000mJ.

[0008] Furthermore, the preset gas is ammonia, the ammonia baking temperature is 95° C. to 110° C., and the baking time is 15 min to 120 min.

[0009] Furthermore, the developer adopts 2.38% TMAH developer, and the developing time is 30s~300s.

[0010] Furthermore, the metal film is any one or more composite films of titanium, nickel, aluminum, platinum, gold, and silver, and the deposition rate of the metal film is 0.5A / min~10A / min, and the thickness is 100A~7μm.

[0011] The present invention also proposes a metal pattern generation system based on the lift-off method, which is characterized by comprising: A mask placement module is used to coat a positive photoresist on a preset substrate, and place a mask plate on the positive photoresist after soft baking, so as to form a mask area and a non-mask area on the positive photoresist; A first exposure module, used for using an exposure machine to expose the material after the mask plate is placed, so that a photoacid area is formed on the non-mask area to obtain a first substrate structure; A baking module, used for placing the first substrate structure into an oven filled with a preset gas for baking, so that the photoacid region on the first substrate structure is neutralized to obtain a second substrate structure; A second exposure module, used for fully exposing the second substrate structure by using the exposure machine, so that the non-neutralized area on the second substrate structure forms a photoacid area, thereby obtaining a third substrate structure; A developing module, used for developing the third substrate structure with a developing solution to form an undercut structure on the third substrate structure to obtain a fourth substrate structure; The metal deposition module is used to deposit a metal film on the fourth substrate structure by physical vapor deposition, and to dissolve the positive photoresist by photoresist removal solution, so as to form a metal pattern on the fourth substrate structure.

[0012] The metal pattern generation method and system based on the stripping method in the present invention use a single layer of positive photoresist, and after exposure, use ammonia baking to neutralize the acid and alkali of the photoacid part of the photoresist, use full exposure to convert the unneutralized area into a photoacid area, and then use a developer for development, so as to form a metal pattern in the subsequent process flow, and form a photoresist profile with an undercut structure through photolithography technology and a single layer of positive photoresist, so that the subsequently deposited metal is discontinuous at the edge of the photoresist pattern, and the photoresist is dissolved in the solution to strip off the metal, thereby forming a fine metal pattern. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a flow chart of a method for generating a metal pattern based on a lift-off method in a first embodiment of the present invention; Figure 2 is a structural diagram of a first substrate structure in a first embodiment of the present invention; Figure 3 is a structural diagram of the second substrate structure in the first embodiment of the present invention; Figure 4 is a structural diagram of a third substrate structure in the first embodiment of the present invention; Figure 5 is a structural diagram of a fourth substrate structure in the first embodiment of the present invention; Figure 6 A structural diagram of the fourth substrate structure after metal film deposition in the first embodiment of the present invention; Figure 7 A structural diagram of forming a metal pattern on a fourth substrate structure in the first embodiment of the present invention; Figure 8 FIG. 4 is a structural block diagram of a metal pattern generation system based on a lift-off method in a second embodiment of the present invention.

[0014] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0015] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0017] Embodiment 1 See also Figure 1 , which shows a metal pattern generation method based on a lift-off method in a first embodiment of the present invention, and the metal pattern generation method based on a lift-off method specifically includes steps S101 to S106: S101, coating a positive photoresist on a preset substrate, soft-baking the positive photoresist, and then placing a mask plate on the positive photoresist to form a mask area and a non-mask area on the positive photoresist; In a specific implementation, a positive photoresist is coated on a preset substrate, the substrate coated with the positive photoresist is soft-baked, and then a mask plate is placed on the positive photoresist to form a mask area and a non-mask area on the positive photoresist; In this embodiment, the coating machine used is a domestically made coating machine MRGS150, which coats the positive photoresist for 5-10s, the thickness of the positive photoresist is 0.8μm-10μm, the soft baking temperature is 80℃-110℃, and the rotation speed is 2500rpm-4000rpm. Preferably, the coating time of the positive photoresist is 5 s, the thickness of the positive photoresist is 0.8 μm, the soft baking temperature is 80° C., and the rotation speed is 2500 rpm.

[0018] S102, using an exposure machine to expose the material after the mask plate is placed, so that a photoacid region is formed on the non-mask region to obtain a first substrate structure; For specific implementation, please refer to Figure 2 , using an exposure machine to expose the material on which the mask plate is placed, so that a photoacid area is formed on the non-mask area to obtain a first substrate structure.

[0019] In this embodiment, the exposure energy of the exposure machine is 5000mJ~10000mJ. Preferably, the exposure energy of the exposure machine is 5000mJ.

[0020] S103, placing the first substrate structure in an oven filled with a preset gas for baking, so that the photoacid region on the first substrate structure is neutralized to obtain a second substrate structure; For specific implementation, please refer to Figure 3 , placing the first substrate structure in an oven filled with a preset gas (in this embodiment, the preset gas is ammonia) for baking, the ammonia baking temperature is 95° C. to 110° C., and the baking time is 15 min to 120 min, so that the photoacid area on the first substrate structure is neutralized to obtain a second substrate structure; Preferably, the ammonia baking temperature is 95° C. and the baking time is 15 min.

[0021] S104, using the exposure machine to fully expose the second substrate structure, so that the non-neutralized area on the second substrate structure forms a photoacid area, thereby obtaining a third substrate structure; For specific implementation, please refer to Figure 4 , using the above-mentioned exposure machine to fully expose the second substrate structure, the full exposure energy of the exposure machine is 5000mJ~10000mJ, so that the non-neutralized area on the second substrate structure forms a photoacid area, and obtains a third substrate structure; Preferably, the total exposure energy is 5000 mJ.

[0022] S105, developing the third substrate structure with a developer to form an undercut structure on the third substrate structure to obtain a fourth substrate structure; For specific implementation, please refer to Figure 5 , developing the third substrate structure with a developer, wherein the developer is a 2.38% TMAH developer, and the developing time is 30s to 300s, so as to form an undercut structure on the third substrate structure to obtain a fourth substrate structure; Preferably, the developing time is 30ss. S106, depositing a metal thin film on the fourth substrate structure by using a physical vapor deposition method, and dissolving the positive photoresist by using a photoresist removal solution, so as to form a metal pattern on the fourth substrate structure.

[0023] For specific implementation, please refer to Figure 6 to Figure 7 , depositing a metal film on the fourth substrate structure by physical vapor deposition, and dissolving the positive photoresist by photoresist removal solution, so as to form a metal pattern on the fourth substrate structure; In this embodiment, a domestically made vapor deposition machine Peva-920EC is used, and the vapor-deposited metal film is any one or more composite films of titanium, nickel, aluminum, platinum, gold, and silver. The deposition rate of the metal film is 0.5A / min~10A / min, and the thickness is 100A~7μm; Preferably, the evaporated metal film is titanium, the deposition rate of the metal film is 5 A / min, and the thickness is 3 μm.

[0024] In summary, the metal pattern generation method based on the stripping method in the above-mentioned embodiment of the present invention uses a single-layer positive photoresist, and after exposure, uses ammonia baking to neutralize the acid and alkali of the photoacid part of the photoresist, uses full exposure to convert the unneutralized area into a photoacid area, and then uses a developer for development, so as to form a metal pattern in the subsequent process flow, and forms a photoresist profile with an undercut structure through photolithography technology and a single-layer positive photoresist, so that the subsequently deposited metal is discontinuous at the edge of the photoresist pattern, and the photoresist is dissolved in the solution to strip off the metal, thereby forming a fine metal pattern.

[0025] Embodiment 2 Another aspect of the present invention is to provide a metal pattern generation system based on the lift-off method. Figure 8 , shown is a metal pattern generation system based on lift-off method in a second embodiment of the present invention, the system comprising: The mask placement module 11 is used to coat a positive photoresist on a preset substrate, and place a mask plate on the positive photoresist after soft baking, so as to form a mask area and a non-mask area on the positive photoresist; A first exposure module 12 is used to expose the material after the mask plate is placed using an exposure machine, so that a photoacid area is formed on the non-mask area to obtain a first substrate structure; A baking module 13 is used to place the first substrate structure into an oven filled with a preset gas for baking, so that the photoacid region on the first substrate structure is neutralized to obtain a second substrate structure; A second exposure module 14 is used to fully expose the second substrate structure by using the exposure machine, so that the non-neutralized area on the second substrate structure forms a photoacid area to obtain a third substrate structure; A developing module 15, used for developing the third substrate structure with a developing solution to form an undercut structure on the third substrate structure to obtain a fourth substrate structure; The metal deposition module 16 is used to deposit a metal film on the fourth substrate structure by physical vapor deposition, and to dissolve the positive photoresist by photoresist removal solution, so as to form a metal pattern on the fourth substrate structure.

[0026] The functions or operation steps implemented when the above modules and units are executed are generally the same as those in the above method embodiments, and will not be repeated here.

[0027] The metal pattern generation system based on the stripping method provided in the embodiment of the present invention has the same implementation principle and technical effects as those in the aforementioned method embodiment. For the sake of brief description, for matters not mentioned in the system embodiment, reference can be made to the corresponding contents in the aforementioned method embodiment.

[0028] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0029] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A method for generating a metal pattern based on a lift-off method, characterized in that: include: Coating a positive photoresist on a preset substrate, soft-baking the positive photoresist, and then placing a mask plate on the positive photoresist to form a mask area and a non-mask area on the positive photoresist; Using an exposure machine to expose the material after the mask plate is placed, so that a photoacid region is formed on the non-mask region to obtain a first substrate structure; The first substrate structure is placed in an oven filled with a preset gas for baking, so that the photoacid region on the first substrate structure is neutralized to obtain a second substrate structure; Fully exposing the second substrate structure by using the exposure machine, so that the non-neutralized area on the second substrate structure forms a photoacid area, thereby obtaining a third substrate structure; developing the third substrate structure with a developer to form an undercut structure on the third substrate structure to obtain a fourth substrate structure; A metal film is deposited on the fourth substrate structure by using a physical vapor deposition method, and a photoresist removal solution is used to dissolve the positive photoresist, so as to form a metal pattern on the fourth substrate structure.

2. The method for generating a metal pattern based on a lift-off method according to claim 1, characterized in that: The thickness of the positive photoresist coated on the preset substrate is 0.8 μm-10 μm, the soft baking temperature is 80° C.-110° C., and the rotation speed is 2500 rpm-4000 rpm.

3. The method for generating a metal pattern based on a lift-off method according to claim 1, characterized in that: The exposure energy and total exposure energy of the exposure machine are both 5000mJ~10000mJ.

4. The method for generating a metal pattern based on a lift-off method according to claim 1, characterized in that: The preset gas is ammonia, the ammonia baking temperature is 95° C. to 110° C., and the baking time is 15 min to 120 min.

5. The method for generating a metal pattern based on a lift-off method according to claim 1, characterized in that: The developer is 2.38% TMAH developer, and the developing time is 30s to 300s.

6. The method for generating a metal pattern based on a lift-off method according to claim 1, characterized in that: The metal film is any one or more composite films of titanium, nickel, aluminum, platinum, gold, and silver. The deposition rate of the metal film is 0.5A / min~10A / min, and the thickness is 100A~7μm.

7. A metal pattern generation system based on a lift-off method, characterized in that: include: A mask placement module is used to coat a positive photoresist on a preset substrate, and after soft-baking the positive photoresist, place a mask plate on the positive photoresist to form a mask area and a non-mask area on the positive photoresist; A first exposure module, used for using an exposure machine to expose the material after the mask plate is placed, so that a photoacid area is formed on the non-mask area to obtain a first substrate structure; A baking module, used for placing the first substrate structure into an oven filled with a preset gas for baking, so that the photoacid region on the first substrate structure is neutralized to obtain a second substrate structure; A second exposure module, used for fully exposing the second substrate structure by using the exposure machine, so that the non-neutralized area on the second substrate structure forms a photoacid area, thereby obtaining a third substrate structure; A developing module, used for developing the third substrate structure with a developing solution to form an undercut structure on the third substrate structure to obtain a fourth substrate structure; The metal deposition module is used to deposit a metal film on the fourth substrate structure by physical vapor deposition, and to dissolve the positive photoresist by photoresist removal solution, so as to form a metal pattern on the fourth substrate structure.

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