Semiconductor device fabrication methods and semiconductor devices
By performing multiple selective exposure processes on the dry film of semiconductor devices to form a stepped inner wall of the via, the problem of film material deposition on the inner wall of the opening is solved, realizing the independence of functional layers and precise dimensional control, improving product yield and simplifying the process flow.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- DOGAIN LASER TECH (SUZHOU) CO LTD
- Filing Date
- 2026-04-14
- Publication Date
- 2026-07-17
AI Technical Summary
In the fabrication of semiconductor devices, the film material is difficult to remove after it is deposited on the inner wall of the opening, resulting in burrs at the edge of the functional layer, which affects the product yield.
A mask structure with a stepped inner wall of a through-hole is formed by multiple selective exposure processes. By performing multiple selective exposure processes on the same dry film, the inner wall of the first through-hole is formed to be stepped. The suspended part of the inner wall blocks the deposited film material, forming an independent functional layer and a redundant layer. After removing the redundant layer, the independent functional layer is obtained.
This effectively prevents the film material from adhering to the inner wall of the opening, reduces the possibility of burrs on the edge of the functional layer, improves product yield, and enables precise control of the size of the functional layer, thereby improving the accuracy of size control and simplifying the process.
Smart Images
Figure CN122069998B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor fabrication technology, and more specifically, to a method for fabricating a semiconductor device and the semiconductor device itself. Background Technology
[0002] In the process of fabricating semiconductor devices, it is often necessary to prepare a functional layer (such as a metal layer) on top of the existing film layer.
[0003] Figures 1-2 The prior art fabrication process is shown, in which several film layers are formed on a substrate 100, collectively referred to as a base layer 200, and an initial mask 101 is disposed on the base layer 200. Film material 103 is deposited on the base layer 200 through an opening 102 in the initial mask 101 to form an initial functional layer 104.
[0004] However, during the deposition process, film material is also easily deposited on the inner wall of the opening 102. After the initial mask 101 is removed, the film material attached to the inner wall of the opening 102 is difficult to remove along with the initial mask 101. As a result, the edge of the initial functional layer 104 is connected to the film material attached to the inner wall of the opening 102, forming burrs, which affects the characteristics of the functional layer and thus affects the product yield of the semiconductor device. Summary of the Invention
[0005] This application provides a method for fabricating a semiconductor device and the semiconductor device itself, the specific technical solution of which is as follows.
[0006] In a first aspect, this application provides a method for fabricating a semiconductor device, comprising:
[0007] A first dry film is applied on the base layer;
[0008] The first dry film is subjected to a first selective exposure treatment to form a first reactive region in which polymerization occurs and a first non-reactive region in which polymerization does not occur; the first reactive region is formed on the periphery of the first non-reactive region.
[0009] The first dry film is subjected to at least one second selective exposure process, such that along the direction away from the base layer, the outer peripheral surface of the first non-reactive part is stepped inward toward the center of the first non-reactive part, and the inner peripheral surface of the first reactive part is stepped outward toward the first non-reactive part.
[0010] The first non-reactive part is removed to form the first through hole, resulting in the first mask structure; the inner circumferential surface of the first reactive part forms the inner wall of the first through hole, and part of the inner wall of the first through hole is suspended on the base layer;
[0011] A first deposition process is performed on the base layer based on the first mask structure. The inner wall of the suspended portion of the first via isolates the film material deposited in the first deposition process, resulting in a first redundant layer and a first functional layer that are separated from each other. The first redundant layer covers the first mask structure, and the first functional layer is located on the base layer exposed by the first via.
[0012] Remove the first mask structure to obtain the semiconductor device.
[0013] In some embodiments, the first dry film undergoes at least one second selective exposure process, including:
[0014] The top layer of the first non-reactive part is subjected to a second selective exposure process using photomasks with different patterns, so that the outer ring of the first non-reactive part undergoes a polymerization reaction from the top layer downwards to a certain depth, forming a part of the first reactive part, and the remaining outer peripheral surface of the first non-reactive part is stepped.
[0015] In the second selective exposure process, on the base layer, the orthographic projection of the light-shielding area of the mask in the first second selective exposure process falls into the central region of the orthographic projection range of the light-shielding area of the mask in the first selective exposure process.
[0016] In the case of multiple second selective exposure processes, on the base layer, the orthographic projection of the photo-shielding area of the mask in the later second selective exposure process falls into the central region of the orthographic projection range of the photo-shielding area of the mask in the previous second selective exposure process.
[0017] In some embodiments, during multiple second selective exposure processes, the exposure energy of the later second selective exposure process is less than the exposure energy of the previous second selective exposure process, such that in each second selective exposure process, a portion of the outer ring of the first non-reactive portion undergoes a polymerization reaction from the top layer downwards, while another portion of the depth does not undergo a polymerization reaction.
[0018] In some embodiments, in the first selective exposure process, a first exposure mask is used, the first exposure mask having a first light-transmitting region and a first light-shielding region; the first light-transmitting region surrounds the first light-shielding region;
[0019] In the first second selective exposure process, a second exposure mask is used. The second exposure mask has a second light transmission area and a second light shielding area. The second light shielding area of the second exposure mask is smaller than the first light shielding area, and the second light transmission area is larger than the first light transmission area.
[0020] In multiple second selective exposure processes, the light-shielding area of the later second selective exposure process is smaller than the light-shielding area of the previous second selective exposure process; the light-transmitting area of the later second selective exposure process is larger than the light-transmitting area of the second selective exposure process.
[0021] The centers of the light-shielding areas of the exposure masks used in all selective exposure processes correspond vertically.
[0022] In some embodiments, after obtaining the first redundant layer and before removing the first mask structure, the method further includes:
[0023] Perform n second deposition processes to obtain the second functional layer, the third functional layer, ..., the (n+1)th functional layer located on the first functional layer; the planar area of all functional layers decreases sequentially along the direction away from the base layer; wherein, the i-th second deposition process includes:
[0024] An i+1 mask structure with an i+1 via is formed on the i-th redundant layer; on the base layer, the orthographic projection of the edge of the i+1 via falls into the central region of the orthographic projection range of the edge of the i-th via, so that the inner wall of the i+1 via is suspended above the i-th mask structure.
[0025] A film material is deposited toward the (i+1)th mask structure, such that the inner wall of the (i+1)th via isolates the film material, resulting in a (i+1)th redundant layer and an (i+1)th functional layer that are separated from each other; the (i+1)th redundant layer covers the (i+1)th mask structure, and the (i+1)th functional layer is located on the (i)th functional layer exposed by the (i+1)th via.
[0026] 1≤i≤n, and n and i are both positive integers; when i=1, the i-th redundant layer includes the first redundant layer, the i-th via includes the first via, and the i-th functional layer includes the first functional layer.
[0027] In some embodiments, an (i+1)th mask structure with an (i+1)th via is formed on the (i)th redundant layer, including:
[0028] A second dry film and a first deposition mask are sequentially disposed on the i-th redundant layer. The second dry film covers the opening of the i-th via. The first deposition mask has a first light-transmitting area and a first light-shielding area. The opening area of the i-th via is larger than the first light-shielding area of the first deposition mask on the i-th via.
[0029] Exposure treatment is performed so that the portion of the second dry film covered by the first light-transmitting area undergoes a polymerization reaction, while the portion of the second dry film covered by the first light-shielding area does not undergo a polymerization reaction.
[0030] The first deposition mask is removed and developed to remove the unpolymerized portion of the second dry film, forming the (i+1)th through-hole, thus obtaining the (i+1)th mask structure.
[0031] In some embodiments, the material of the first dry film includes acrylic resin;
[0032] The surface of the base layer includes metallic materials.
[0033] In some embodiments, the thickness of the first dry film is not less than 20 micrometers and not more than 30 micrometers.
[0034] In some embodiments, it also includes:
[0035] Based on the dimension x of the first functional layer along the first direction, the height d of the top step of the inner wall of the first through hole, and the distance h from the first functional layer to the vapor deposition source, the dimension c of the top step of the inner wall of the first through hole along the first direction is determined; the first direction is parallel to the base layer.
[0036] in, c <x;
[0037] Based on the dimension c along the first direction at the top step of the inner wall of the first through hole, the dimension x along the first direction of the first functional layer, and the dimension a along the first direction at the bottom of the first through hole, the dimension b along the first direction at the secondary step of the inner wall of the first through hole from the top down is determined.
[0038] Where, x <b<a。
[0039] Secondly, this application provides a semiconductor device prepared using any of the preparation methods provided in the first aspect above, comprising:
[0040] base layer;
[0041] The first functional layer is formed on top of the foundation layer.
[0042] The semiconductor device fabrication method and semiconductor device provided in this application have the following technical advantages:
[0043] This application obtains a first mask structure with a first through-hole by performing multiple selective exposure processes on the same first dry film. The inner wall of the first through-hole is stepped, so part of the inner wall of the first through-hole is suspended above the base layer. During the first deposition process, the suspended part of the inner wall is empty below, causing the deposited film material to break at the suspension point. Part of the film material is deposited flat on the base layer to form the required first functional layer, and the other part of the film material is attached to the first mask structure to form a first redundant layer. By removing the first mask structure, the first redundant layer can be removed at the same time, and the first functional layer that exists independently on the base layer can be obtained.
[0044] Because the first functional layer is disconnected from the first redundancy layer, it can avoid Figures 1-2The prior art shown depicts a situation where the deposited film material adheres to the inner wall of the opening, thereby reducing the possibility of burrs appearing at the edge of the first functional layer, ensuring the characteristics of the first functional layer, and improving the product yield of semiconductor devices.
[0045] Furthermore, by setting a first dry film, the first through-hole is obtained by selectively exposing the same first dry film multiple times. The size of the first functional layer can be precisely controlled according to the shape and size of the first through-hole, resulting in high size control accuracy, which is beneficial to improving product yield.
[0046] In this process, the first dry film undergoes a first selective exposure treatment, causing polymerization to occur in the internal region of the first dry film along a first direction, forming a first reactive region, while the external region of the first dry film does not undergo polymerization and serves as a first non-reactive region. The first dry film then undergoes at least one second selective exposure treatment, causing the boundary between the first non-reactive region and the first reactive region to be stepped along the thickness direction. Since the first non-reactive region does not undergo polymerization, it is easily removed by the developer, and the remaining first reactive region can serve as a first mask structure, facilitating subsequent deposition processes. Attached Figure Description
[0047] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0048] Figures 1-2 This is a schematic diagram of the membrane structure used in the prior art for preparing the initial functional layer;
[0049] Figure 3 A schematic flowchart illustrating a method for fabricating a semiconductor device according to an embodiment of this application;
[0050] Figure 4 This is a schematic diagram of the film structure after the first dry film is set in a method for fabricating a semiconductor device according to an embodiment of this application.
[0051] Figures 5-6 This is a schematic diagram of the film structure undergoing the first selective exposure process in a method for fabricating a semiconductor device according to an embodiment of this application.
[0052] Figures 7-8 This is a schematic diagram of the film structure undergoing the first second selective exposure process in a method for fabricating a semiconductor device according to an embodiment of this application.
[0053] Figures 9-10This is a schematic diagram of the film structure undergoing a second selective exposure process in a method for fabricating a semiconductor device according to an embodiment of this application.
[0054] Figure 11 This is a schematic diagram of the film structure after removing the first non-reactive part in a method for fabricating a semiconductor device according to an embodiment of this application.
[0055] Figure 12 This is a schematic diagram of the film structure after the first deposition process in a method for fabricating a semiconductor device according to an embodiment of this application.
[0056] Figure 13 for Figure 12 A simplified structural diagram;
[0057] Figures 14-17 This is a schematic diagram of the film layer structure for forming the second mask structure in a method for fabricating a semiconductor device according to an embodiment of this application.
[0058] Figure 18 This is a schematic diagram of the film structure after the second deposition process in a method for fabricating a semiconductor device according to an embodiment of this application.
[0059] Figure 19 This is a schematic diagram of the film structure of a semiconductor device provided in an embodiment of this application.
[0060] Figure label:
[0061] 100 - Substrate; 101 - Initial mask; 102 - Opening; 103 - Film material; 104 - Initial functional layer;
[0062] 200 - Basic Layer;
[0063] 300 - First mask structure; 301 - First through hole;
[0064] 310 - First dry film; 311 - First reactive section; 312 - First non-reactive section; 320 - First exposure mask; 321 - First light-transmitting area; 322 - First light-shielding area; 330 - Second exposure mask; 331 - Second light-transmitting area; 332 - Second light-shielding area; 340 - Third exposure mask;
[0065] 401 - First Redundancy Layer; 402 - First Functional Layer;
[0066] 501 - Second Redundancy Layer; 502 - Second Functional Layer;
[0067] 600 - Second mask structure; 601 - Second through hole;
[0068] 610 - Second dry film; 620 - First deposition mask; 621 - First light-transmitting area; 622 - First light-shielding area;
[0069] 700 - Evaporation source. Detailed Implementation
[0070] The embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the embodiments described below with reference to the accompanying drawings are exemplary descriptions for explaining the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions of the embodiments of this application.
[0071] Those skilled in the art will understand that, unless specifically stated otherwise, the terms "described" and "the" as used herein may also include plural forms. It should be further understood that the term "comprising" as used in this application's specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude implementations of other features, information, data, steps, operations, elements, components, and / or combinations thereof supported by this art. It should be understood that when we say an element is "connected" or "coupled" to another element, the element may be directly connected or coupled to the other element, or it may mean that the element and the other element are connected through an intermediate element. Furthermore, "connected" or "coupled" as used herein may include wireless connections or wireless coupling. The term "and / or" as used herein refers to at least one of the items defined by the term; for example, "A and / or B" may be implemented as "A," or as "B," or as "A and B."
[0072] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.
[0073] This application provides a method for fabricating a semiconductor device, the process flow diagram of which is shown below. Figure 3 As shown, the method includes steps S1 to S6:
[0074] S1: As Figure 4 As shown, a first dry film 310 is disposed on the base layer 200.
[0075] S2: As Figures 5-6 As shown, the first dry film 310 is subjected to a first selective exposure treatment to form a first reactive portion 311 in which a polymerization reaction occurs and a first non-reactive portion 312 in which a polymerization reaction does not occur; the first reactive portion 311 is formed on the periphery of the first non-reactive portion 312.
[0076] S3: As Figures 7-10As shown, the first dry film 310 is subjected to at least one second selective exposure process, such that along the direction away from the base layer 200, the outer peripheral surface of the first non-reactive portion 312 is stepped inward toward the center of the first non-reactive portion 312, and the inner peripheral surface of the first reactive portion 311 is stepped outward toward the first non-reactive portion 312.
[0077] S4: As Figure 11 As shown, the first non-reactive part 312 is removed to form the first through hole 301, resulting in the first mask structure 300; the inner circumferential surface of the first reactive part 311 forms the inner wall of the first through hole 301, and part of the inner wall of the first through hole 301 is suspended on the base layer 200.
[0078] S5: As Figure 12 As shown, a first deposition process is performed on the base layer 200 based on the first mask structure 300. The inner wall of the suspended portion of the first through hole 301 blocks the film material deposited in the first deposition process, resulting in a first redundant layer 401 and a first functional layer 402 that are separated from each other. The first redundant layer 401 covers the first mask structure 300, and the first functional layer 402 is located on the base layer 200 exposed by the first through hole 301.
[0079] S6: As Figure 19 As shown, the first mask structure 300 is removed to obtain the semiconductor device.
[0080] In this embodiment, by performing multiple selective exposure processes on the same first dry film 310, a first mask structure 300 with a first through-hole 301 is obtained. The inner wall of the first through-hole 301 is stepped. Therefore, part of the inner wall of the first through-hole 301 is suspended above the base layer 200. During the first deposition process, the suspended part of the inner wall is empty below, causing the deposited film material to break at the suspended part. Part of the film material is deposited flat on the base layer 200 to form the required first functional layer 402, and another part of the film material is attached to the first mask structure 300 to form a first redundant layer 401. By removing the first mask structure 300, the first redundant layer 401 can be removed at the same time, and the first functional layer 402 that exists independently on the base layer 200 is obtained.
[0081] Since the first functional layer 402 is disconnected from the first redundancy layer 401, it can avoid Figures 1-2 The prior art shown has a deposited film material attached to the inner wall of the opening 102, thereby reducing the possibility of burrs appearing at the edge of the first functional layer 402, ensuring the characteristics of the first functional layer 402, and improving the product yield of semiconductor devices.
[0082] Furthermore, by setting the first dry film 310, the first through hole 301 is obtained by performing multiple selective exposure processes on the same first dry film 310. The size of the first functional layer 402 can be precisely controlled according to the shape and size of the first through hole 301. The size control accuracy is high, which is beneficial to improving the product yield.
[0083] In this process, the first dry film 310 undergoes a first selective exposure treatment, causing polymerization to occur in the internal region of the first dry film 310 along a first direction, forming a first reactive region 311, while the external region of the first dry film 310 does not undergo polymerization and serves as a first non-reactive region 312. The first dry film 310 then undergoes at least one second selective exposure treatment, causing the boundary between the first non-reactive region 312 and the first reactive region 311 to be stepped along the thickness direction. Since the first non-reactive region 312 does not undergo polymerization, it is easily removed by the developer, and the remaining first reactive region 311 can serve as a first mask structure 300, facilitating subsequent deposition processes.
[0084] The research and development approach of this application also includes: in related technologies, multiple coatings of photoresist are applied, with each coating followed by a photolithography process to form a mask structure. Photoresist is generally thin and does not support multiple exposures. Each photolithography process requires coating, spin coating, pre-baking, exposure, and post-baking, making the process complex. Compared to related technologies that form mask structures through multiple photolithography processes, this application obtains a first mask structure 300 by repeatedly exposing the same first dry film 310. The first dry film 310 can be exposed multiple times, requiring only molding, exposure, and development steps, without etching. This simplifies the process, avoids the problem of poor interlayer adhesion in existing technologies, and improves the reliability of the first mask structure 300 itself. Furthermore, it avoids interlayer overlay errors caused by multiple photolithography alignments in existing technologies. Compared to photolithography, it is easier to control the dimensional accuracy of the first via 301 and the size of the formed first functional layer 402.
[0085] It should be noted that some film layers are formed on the substrate 100, collectively referred to as the base layer 200.
[0086] It should be noted that in this embodiment, the same first dry film 310 undergoes multiple selective exposure processes, namely, one first selective exposure process and at least one second selective exposure process, to obtain the first mask structure 300. The first selective exposure process exposes the entire thickness of the first dry film 310, while the second selective exposure process exposes only a portion of the first dry film 310 from the top layer downwards. The process of selective exposure will be described in detail below.
[0087] Optionally, the film material is a metallic material.
[0088] In some embodiments, in step S2 above, such as Figure 5 As shown, a first exposure mask 320 is disposed on the first dry film 310, such as... Figure 6 As shown, a first selective exposure process can be performed on the first dry film 310 based on the first exposure mask 320, allowing light to pass through the first light-transmitting area 321 of the first exposure mask 320 to the lower first dry film 310. This causes the portion of the first dry film 310 exposed to light to undergo a polymerization reaction, forming a first reactive portion 311. The first light-shielding area 322 of the first exposure mask 320 can block light, so the lower first dry film 310 does not undergo a polymerization reaction, forming a first non-reactive portion 312. In the first exposure mask 320, the first light-transmitting area 321 is formed on the outer periphery of the first light-shielding area 322, and correspondingly, the first reactive portion 311 is formed on the outer periphery of the first non-reactive portion 312.
[0089] In some embodiments, in step S3 above, such as Figures 7-10 As shown, the first dry film 310 undergoes at least one second selective exposure process, including the following steps:
[0090] The top layer of the first non-reactive part 312 is subjected to a second selective exposure process using photomasks with different patterns, so that the outer ring of the first non-reactive part 312 undergoes a polymerization reaction from the top layer downwards to a certain depth, forming a part of the first reactive part 311, and the remaining outer peripheral surface of the first non-reactive part 312 is stepped.
[0091] In the second selective exposure process, on the base layer 200, the orthographic projection of the light-shielding area of the mask in the first second selective exposure process falls into the central region of the orthographic projection range of the light-shielding area of the mask in the first selective exposure process.
[0092] In the case of multiple second selective exposure processes, on the base layer 200, the orthographic projection of the light-shielding area of the mask in the later second selective exposure process falls into the center region of the orthographic projection range of the light-shielding area of the mask in the previous second selective exposure process.
[0093] In this embodiment, the mask used in the second selective exposure process also includes a light-shielding area. The light-shielding area can block the exposure light and selectively block the first non-reactive part 312 of the first dry film 310 to prevent the first dry film 310 from undergoing a complete polymerization reaction, so as to facilitate the subsequent development and removal of the first dry film 310 that has not undergone a polymerization reaction.
[0094] The light-shielding area of the mask in the first selective exposure process is smaller than that of the mask in the first selective exposure process. This causes the orthographic projection of the light-shielding area of the mask in the first selective exposure process on the base layer 200 to fall into the center region of the orthographic projection range of the light-shielding area of the mask in the first selective exposure process. As a result, during the first selective exposure process, the outer ring of the first non-reactive part 312 is exposed to the exposure light source, while the inner ring of the first non-reactive part 312 is blocked by the light-shielding area. By controlling the exposure depth, only a portion of the thickness of the outer ring is exposed, thus turning the exposed first non-reactive part 312 into the first reactive part 311.
[0095] Similarly, the light-shielding area of the mask in the second selective exposure process is smaller than that in the first selective exposure process. This causes the orthographic projection of the light-shielding area of the mask in the second selective exposure process on the base layer 200 to fall into the center region of the orthographic projection range of the light-shielding area of the mask in the first selective exposure process. As a result, during the second selective exposure process, the outer ring of the first non-reactive part 312 is exposed to the exposure light source, while the inner ring of the first non-reactive part 312 is blocked by the light-shielding area. The exposure depth is controlled so that only a portion of the thickness of the outer ring is exposed, making the exposed first non-reactive part 312 become the first reactive part 311.
[0096] In this operation, the junction between the first reactive part 311 and the first non-reactive part 312 is stepped, and the first non-reactive part 312 is located inside the first reactive part 311. By developing and removing the first non-reactive part 312, the area where the first non-reactive part 312 is located forms a first through hole 301, thereby obtaining a first through hole 301 with a stepped inner wall.
[0097] Next, taking a total of three selective exposure processes as an example, in this embodiment, the thickness of the first dry film 310 is D. After the first selective exposure process, the thicknesses of the first reactive portion 311 and the first non-reactive portion 312 are also D. Dividing D into three equal parts, and then undergoing a second selective exposure process, the thickness of the outer ring of the first non-reactive portion 312 exposed from the top layer downwards is... A polymerization reaction occurs, forming part of the first reactive section 311. One-third of the outer layer thickness of the first non-reactive section 312 remains unexposed. Then, after a second selective exposure, the thickness of the outer layer of the first non-reactive section 312 exposed from the top down is... A polymerization reaction occurs, becoming part of the first reactive section 311. Two-thirds of the outer layer thickness of the first non-reactive section 312 remains unexposed, thus obtaining... Figure 11 The first through hole 301 shown has a three-tiered stepped inner wall.
[0098] In some embodiments, during multiple second selective exposure processes, the exposure energy of the later second selective exposure process is less than the exposure energy of the previous second selective exposure process, so that in each second selective exposure process, a portion of the outer ring of the first non-reactive part 312 from the top layer downwards undergoes a polymerization reaction, while another portion of the depth does not undergo a polymerization reaction.
[0099] In this embodiment, by controlling the exposure energy and thus the exposure depth, the depth of polymerization reaction occurring on the outer ring of the first non-reactive part 312 is controlled in each selective exposure process. By successively decreasing the exposure energy, the exposure depth can be successively decreased, resulting in a stepped shape on the outer periphery of the first non-reactive part 312. The solution provided in this embodiment enables controllable exposure depth and yields a more regular pattern.
[0100] Optionally, ultraviolet light with a wavelength of 405 nanometers is exposed. Since the ultraviolet light cannot penetrate the light-shielding area, the lower first dry film 310 cannot undergo a polymerization reaction. Alternatively, if the ultraviolet light can penetrate the light-transmitting area, the lower first dry film 310 will undergo a polymerization reaction.
[0101] Optionally, the exposure energy used in the first selective exposure process is 80 mJ / cm² (millijoules per square centimeter), the exposure energy used in the first second selective exposure process is about two-thirds of the exposure energy used in the first selective exposure process, i.e., 53 mJ / cm², and the exposure energy used in the second second selective exposure process is half of the exposure energy used in the first second selective exposure process, i.e., 27 mJ / cm².
[0102] In some embodiments, such as Figures 5-10 As shown, in the first selective exposure process, a first exposure mask 320 is used. The first exposure mask 320 has a first light-transmitting region 321 and a first light-shielding region 322; the first light-transmitting region 321 surrounds the first light-shielding region 322.
[0103] In the first second selective exposure process, a second exposure mask 330 is used. The second exposure mask 330 has a second light transmission area 331 and a second light shielding area 332. The second light shielding area 332 of the second exposure mask 330 is smaller than the first light shielding area 322 and larger than the first light transmission area 321.
[0104] In multiple second selective exposure processes, the light-shielding area of the later second selective exposure process is smaller than the light-shielding area of the previous second selective exposure process; the light-transmitting area of the later second selective exposure process is larger than the light-transmitting area of the second selective exposure process.
[0105] The centers of the light-shielding areas of the exposure masks used in all selective exposure processes correspond vertically.
[0106] In this embodiment, by adopting the above-mentioned exposure method and sequentially setting exposure masks with center alignment and progressively smaller light shielding areas, the shape, size, and depth distribution of the exposure area can be made more uniform and controllable, effectively improving the verticality of the pattern and the processing accuracy, expanding the process window, and improving product yield and consistency.
[0107] It should be noted that the vertical alignment of the centers of the light-shielding areas of all exposure masks means that the centers of the light-shielding areas of each of the multiple exposure masks used in the first selective exposure process and the second selective exposure process are aligned vertically. However, a certain degree of error is allowed.
[0108] For example, when the second selective exposure process is performed twice, such as... Figures 5-6 As shown, in the first selective exposure process, a first exposure mask 320 is used, such as... Figures 7-8 As shown, in the first and second selective exposure process, a second exposure mask 330 is used, such as... Figures 9-10 As shown, in the second selective exposure process, a third exposure mask 340 is used. The three exposure masks are sequentially disposed on the first dry film 310. When the light-shielding areas of the first exposure mask 320, the second exposure mask 330, and the third exposure mask 340 are each present, their centers are aligned vertically.
[0109] In some embodiments, please refer to Figures 14-18 After obtaining the first redundant layer 401 and before removing the first mask structure 300, the following steps are also included:
[0110] Performing n second deposition processes yields the second functional layer 502, the third functional layer, ..., the (n+1)th functional layer located on the first functional layer 402; along the direction away from the base layer 200, the planar area of all functional layers decreases sequentially; wherein, the i-th second deposition process includes:
[0111] An i+1 mask structure with an i+1 via is formed on the i-th redundant layer; on the base layer 200, the orthographic projection of the edge of the i+1 via falls into the central region of the orthographic projection range of the edge of the i-th via, so that the inner wall of the i+1 via is suspended above the i-th mask structure.
[0112] A film material is deposited toward the (i+1)th mask structure, such that the inner wall of the (i+1)th via isolates the film material, resulting in a (i+1)th redundant layer and an (i+1)th functional layer that are separated from each other; the (i+1)th redundant layer covers the (i+1)th mask structure, and the (i+1)th functional layer is located on the (i)th functional layer exposed by the (i+1)th via.
[0113] 1≤i≤n, and n and i are both positive integers; when i=1, the i-th redundant layer includes the first redundant layer 401, the i-th through hole includes the first through hole 301, and the i-th functional layer includes the first functional layer 402.
[0114] In this embodiment, at least one deposition process is performed sequentially over the first mask structure 300 that has been cured after polymerization reaction to obtain at least one functional layer above the first functional layer 402, thereby realizing the layer-by-layer stacking preparation of multiple burr-free functional layers.
[0115] It should be noted that after the first functional layer 402 is prepared through the first deposition process, the second deposition process can be performed n times. n is the total number of second deposition processes, and i is one of the second deposition processes.
[0116] For example, when n=i=1, that is, after the first functional layer 402 is prepared, a second deposition process is performed to obtain a second functional layer 502 located on the first functional layer 402; along the direction away from the base layer 200, the planar area of the second functional layer 502 is smaller than that of the first functional layer 402; wherein, the first second deposition process includes:
[0117] like Figures 14-17 As shown, a second mask structure 600 with a second through hole 601 is formed on the first redundant layer 401; on the base layer 200, the orthographic projection of the edge of the second through hole 601 falls into the central region of the orthographic projection range of the edge of the first through hole 301, so that the inner wall of the second through hole 601 is suspended above the first mask structure.
[0118] like Figure 18 As shown, a film material is deposited toward the second mask structure 600, such that the inner wall of the second through hole 601 blocks the film material, resulting in a second redundant layer 501 and a second functional layer 502 that are separated from each other; the second redundant layer 501 covers the second mask structure 600, and the second functional layer 502 is located on the first functional layer 402 exposed by the second through hole 601.
[0119] When n=2, two second deposition processes are performed to obtain a second functional layer 502 and a third functional layer located on the first functional layer 402; along the direction away from the base layer 200, the planar areas of the third functional layer, the second functional layer 502, and the first functional layer 402 decrease sequentially; wherein, the second deposition process includes:
[0120] A third mask structure with a third through hole is formed on the second redundant layer 501; on the base layer 200, the orthographic projection of the edge of the third through hole falls into the central region of the orthographic projection range of the edge of the second through hole 601, so that the inner wall of the third through hole is suspended above the second mask structure 600.
[0121] A film material is deposited toward the third mask structure, such that the inner wall of the third through hole isolates the film material, resulting in a mutually separated third redundant layer and third functional layer; the third redundant layer covers the third mask structure, and the third functional layer is located on the second functional layer 502 exposed by the third through hole.
[0122] Then, the first mask structure 300 is removed to obtain a semiconductor device with multiple functional layers.
[0123] In some embodiments, forming the (i+1)th mask structure with the (i+1)th via on the (i)th redundant layer in the above steps includes the following steps:
[0124] like Figure 5 As shown, a second dry film 610 and a first deposition mask 620 are sequentially disposed on the i-th redundant layer. The second dry film 610 covers the opening of the i-th via. The first deposition mask 620 has a first light-transmitting area 621 and a first light-shielding area 622. The opening area of the i-th via is larger than the first light-shielding area 622 of the first deposition mask 620 on the i-th via.
[0125] like Figure 16 As shown, an exposure process is performed, causing the portion of the second dry film 610 covered by the first light-transmitting region 621 to undergo a polymerization reaction, while the portion of the second dry film 610 covered by the first light-shielding region 622 does not undergo a polymerization reaction.
[0126] like Figure 17 As shown, the first deposition mask 620 is removed and developed, and the portion of the second dry film 610 that has not undergone polymerization is removed to form the (i+1)th through hole, thus obtaining the (i+1)th mask structure.
[0127] In this embodiment, the method of forming the mask structure is defined. Specifically, for each functional layer formed, a new second dry film 610 is formed above the corresponding redundant layer. The new second dry film 610 is etched based on a new deposition mask to obtain a multi-layer mask structure. During the multiple etching processes of the second dry film 610, the light-shielding area of the deposition mask used decreases sequentially, and the opening areas of the multiple mask structures decrease sequentially. This makes the opening area of the upper second dry film 610 suspended relative to the lower second dry film 610, thereby making the area of the functional layer deposited through the upper opening area decrease sequentially. Moreover, the inner wall of the suspended opening can isolate the deposited material, and the formed functional layer is free of burrs.
[0128] For example, when n=i=1, the step of forming a second mask structure 600 with a second via 601 on the first redundant layer includes the following steps:
[0129] like Figure 14 As shown, a second dry film 610 and a first deposition mask 620 are sequentially disposed on the first redundant layer. The second dry film 610 covers the opening of the first through hole 301. The first deposition mask 620 has a first light-transmitting area 621 and a first light-shielding area 622. The opening area of the first through hole 301 is larger than the first light-shielding area 622 of the first deposition mask 620 on the first through hole 301.
[0130] like Figures 15-16 As shown, an exposure process is performed, causing the portion of the second dry film 610 covered by the first light-transmitting region 621 to undergo a polymerization reaction, while the portion of the second dry film 610 covered by the first light-shielding region 622 does not undergo a polymerization reaction.
[0131] like Figure 17 As shown, the first deposition mask 620 is removed and developed to remove the portion of the second dry film 610 that has not undergone polymerization reaction, forming the second through hole 601, and obtaining the second mask structure 600.
[0132] Optionally, the first mask structure 300 can be peeled off by organic soaking, and the redundant layer above the first mask structure 300 and other mask structures are also peeled off at the same time.
[0133] In some embodiments, the material of the first dry film 310 includes acrylic resin.
[0134] The surface of the base layer 200 includes a metallic material.
[0135] In this embodiment, the base layer 200 can be a film layer including a metal material, and its surface has a metal material, so that the first dry film 310 made of acrylic resin has good photosensitivity and resolution, can accurately realize pattern transfer, and ensure exposure accuracy.
[0136] In some embodiments, the thickness of the first dry film 310 is not less than 20 micrometers and not more than 30 micrometers.
[0137] In this embodiment, by setting the thickness of the first dry film 310 to be not less than 20 micrometers and not more than 30 micrometers, the first mask structure 300 with the first through hole 301 having a stepped inner wall can be obtained by performing multiple selective exposure processes on the same first dry film 310, which has strong morphological controllability.
[0138] In some embodiments, the preparation method further includes:
[0139] Based on the dimension x of the first functional layer 402 along the first direction, the height d of the suspension at the top step of the inner wall of the first through hole 301, and the distance h from the first functional layer 402 to the evaporation source 700, the dimension c of the top step of the inner wall of the first through hole 301 along the first direction is determined; the first direction is parallel to the base layer 200; wherein... c <x。
[0140] Based on the dimension c along the first direction at the top step of the inner wall of the first through hole 301, the dimension x along the first direction of the first functional layer 402, and the dimension a along the first direction at the bottom of the first through hole 301, the dimension b along the first direction at the secondary step from the top down of the inner wall of the first through hole 301 is determined; where x <b<a。
[0141] It should be noted that the inner wall of the first through hole 301 of the first mask structure 300 is stepped. Starting from the top layer, the topmost step is the top step. Along the first direction, the inner wall size of the top step is the minimum opening size of the first through hole 301. The second step is the secondary step, and the bottom dimension a is the maximum opening size of the first through hole 301.
[0142] In this embodiment, as Figures 12-13 As shown, Figure 13 for Figure 12 A simplified structural diagram is provided to facilitate the reader's understanding of the proposed solution in this embodiment. The relationship between four parameters—the dimension x of the first functional layer 402 along the first direction, the height d of the top step of the inner wall of the first through-hole 301, the distance h from the first functional layer 402 to the evaporation source 700, and the dimension c of the top step of the inner wall of the first through-hole 301 along the first direction—can be obtained through the properties of similar triangles. Here, x is predetermined based on the characteristics of the first function, h is also predetermined, and d is related to the thickness D of the first mask structure 300. The data for d can be determined through the manufacturing process of the first mask structure 300, and thus the data for c can be determined. For example, if the thickness D of the first mask structure 300 is designed to be 25 micrometers, and a three-layer stepped structure is obtained through one first selective exposure and two second selective exposures, where the thickness of each step is consistent, then d is... .
[0143] Understandably, the first functional layer 402 is very thin, its thickness is negligible, and the vapor deposition source 700 is located at the center directly above the first functional layer 402. The figure shows two similar triangles; one triangle has the vapor deposition source 700 as its apex and the base as... One is a right-angled triangle with height h, and the other has its vertex at the secondary step on the inner wall of the first through hole 301 from the top down, and its base is... , a right triangle with height d. These two right triangles share a base angle, and the apex angles and right angles are the same, so they are similar triangles. Therefore, the following formula can be obtained:
[0144] ;
[0145] By converting the above formula, the following can be obtained:
[0146] .
[0147] Furthermore, as Figures 12-13 shown, the dimension b of the secondary step along the first direction from the top level of the inner wall of the first through hole 301 can be determined by the dimension c along the first direction at the top level step of the inner wall of the first through hole 301, the dimension x along the first direction of the first functional layer 402, and the dimension a along the first direction at the bottom end of the first through hole 301. Specifically, along the first direction, c is the smallest, and the dimension x of the deposited first functional layer 402 will be slightly larger than c under the divergence effect. At the inner wall of the first through hole 301, the dimension b at the secondary step is larger than the dimension a at the bottom end, so c < x < b < a. Therefore, the range of b can be determined.
[0148] Similarly, as Figure 18 shown, before preparing the second functional layer 502, the dimension e of the second through hole 601 along the first direction can be determined based on the dimension y of the second functional layer 502 along the first direction, the height D of the inner wall of the second through hole 601 being suspended (which is also the thickness D of the first mask structure 300), and the distance h from the second functional layer 502 to the evaporation source 700;
[0149] Using the similar triangle properties similar to the above, two similar triangles can be formed. One is a right triangle with the evaporation source 700 as the apex, the base being , and the height being h. The other is a right triangle with the bottom end of the second through hole 601 as the apex angle, the base being , and the height being g. These two right triangles share a base angle, and the apex angles and right angles are the same, so they are similar triangles. Therefore, the following formula can be obtained:
[0150] ;
[0151] By converting the above formula, the following can be obtained:
[0152] .
[0153] Thus, the dimension of the second through hole 601 can be determined through the above formula.
[0154] In some embodiments, the first functional layer is a metal layer, and the second functional layer is also a metal layer.
[0155] Based on the same inventive concept, such as Figure 19 As shown, this application embodiment also provides a semiconductor device, which is prepared by the preparation method provided in any of the above embodiments, including: a base layer 200 and a first functional layer 402, wherein the first functional layer 402 is formed on the base layer 200.
[0156] In this embodiment, the semiconductor device fabrication method provided in the previous embodiment is used, and its technology and principle are similar, so it will not be described again here. Because the semiconductor device fabrication method provided in the previous embodiment is used, the edge of the first functional layer 402 of the semiconductor device in this embodiment is basically free of burrs, which can ensure the good characteristics of the first functional layer 402 and improve the product yield of the semiconductor device.
[0157] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.
Claims
1. A method for fabricating a semiconductor device, characterized in that, include: A first dry film (310) is disposed on the base layer (200); The first dry film (310) is subjected to a first selective exposure treatment to form a first reactive section (311) in which polymerization occurs and a first non-reactive section (312) in which polymerization does not occur; the first reactive section (311) is formed on the periphery of the first non-reactive section (312); The first dry film (310) is subjected to at least one second selective exposure process, such that the outer peripheral surface of the first non-reactive part (312) is stepped inward toward the center of the first non-reactive part (312) in a direction away from the base layer (200), and the inner peripheral surface of the first reactive part (311) is stepped outward toward the first non-reactive part (312). Remove the first non-reactive part (312) to form a first through hole (301) and obtain a first mask structure (300); the inner peripheral surface of the first reactive part (311) forms the inner wall of the first through hole (301), and part of the inner wall of the first through hole (301) is suspended on the base layer (200); A first deposition process is performed on the base layer (200) based on the first mask structure (300). The inner wall of the suspended portion of the first through hole (301) blocks the film material deposited in the first deposition process, resulting in a first redundant layer (401) and a first functional layer (402) that are separated from each other. The first redundant layer (401) covers the first mask structure (300), and the first functional layer (402) is located on the base layer (200) exposed by the first through hole (301). Remove the first mask structure (300) to obtain a semiconductor device.
2. The preparation method according to claim 1, characterized in that, The first dry film (310) undergoes at least one second selective exposure process, including: The top layer of the first non-reactive part (312) is subjected to a second selective exposure process using a mask with different patterns, so that the outer ring of the first non-reactive part (312) undergoes a polymerization reaction from the top layer downwards to a certain depth, forming a part of the first reactive part (311), and the remaining outer peripheral surface of the first non-reactive part (312) is stepped. In the second selective exposure process, on the base layer (200), the orthographic projection of the light-shielding area of the mask in the first second selective exposure process falls into the central region of the orthographic projection range of the light-shielding area of the mask in the first selective exposure process. In the case of multiple second selective exposure processes, on the base layer (200), the orthographic projection of the light-shielding area of the mask in the later second selective exposure process falls into the central region of the orthographic projection range of the light-shielding area of the mask in the previous second selective exposure process.
3. The preparation method according to claim 2, characterized in that, In multiple second selective exposure processes, the exposure energy of the later second selective exposure process is less than the exposure energy of the previous second selective exposure process, so that in each second selective exposure process, a part of the outer ring of the first non-reactive part (312) from the top layer downwards undergoes a polymerization reaction, while another part of the depth does not undergo a polymerization reaction.
4. The preparation method according to claim 2, characterized in that, In the first selective exposure process, a first exposure mask (320) is used, which has a first light-transmitting region (321) and a first light-shielding region (322); the first light-transmitting region (321) is disposed outside the first light-shielding region (322); In the first second selective exposure process, a second exposure mask (330) is used. The second exposure mask (330) has a second light transmission area (331) and a second light shielding area (332). The second light shielding area (332) of the second exposure mask (330) is smaller than the first light shielding area (322), and the second light transmission area (331) is larger than the first light transmission area (321). In multiple second selective exposure processes, the light shielding area of the later second selective exposure process is smaller than the light shielding area of the previous second selective exposure process. The light transmission area of the subsequent second selective exposure process is larger than the light transmission area of the second selective exposure process. The centers of the light-shielding areas of the exposure masks used in all selective exposure processes correspond vertically.
5. The preparation method according to claim 1, characterized in that, After obtaining the first redundant layer (401) and before removing the first mask structure (300), the process further includes: Perform n second deposition processes to obtain a second functional layer (502), a third functional layer, ..., an (n+1)th functional layer located on the first functional layer (402); the planar area of all functional layers decreases sequentially along the direction away from the base layer (200); wherein, the i-th second deposition process includes: An i+1 mask structure with an i+1 via is formed on the i-th redundant layer; on the base layer (200), the orthographic projection of the edge of the i+1 via falls into the central region of the orthographic projection range of the edge of the i-th via, so that the inner wall of the i+1 via is suspended above the i-th mask structure. A film material is deposited toward the (i+1)th mask structure, such that the inner wall of the (i+1)th via blocks the film material, resulting in a (i+1)th redundant layer and an (i+1)th functional layer that are separated from each other; the (i+1)th redundant layer covers the (i+1)th mask structure, and the (i+1)th functional layer is located on the (i)th functional layer exposed by the (i+1)th via. 1≤i≤n, and n and i are both positive integers; when i=1, the i-th redundant layer includes the first redundant layer (401), the i-th through hole includes the first through hole (301), and the i-th functional layer includes the first functional layer (402).
6. The preparation method according to claim 5, characterized in that, Forming an (i+1)th mask structure with an (i+1)th via on the (i)th redundant layer includes: A second dry film (610) and a first deposition mask (620) are sequentially disposed on the i-th redundant layer. The second dry film (610) covers the opening of the i-th via. The first deposition mask (620) has a first light-transmitting area (621) and a first light-shielding area (622). The opening area of the i-th via is larger than the first light-shielding area (622) of the first deposition mask (620) on the i-th via. Exposure processing is performed so that the portion of the second dry film (610) covered by the first light-transmitting area (621) undergoes a polymerization reaction, while the portion of the second dry film (610) covered by the first light-shielding area (622) does not undergo a polymerization reaction. Remove the first deposition mask (620) and perform development treatment to remove the portion of the second dry film (610) that has not undergone polymerization reaction, forming the (i+1)th through hole, and obtain the (i+1)th mask structure.
7. The preparation method according to claim 1, characterized in that, The material of the first dry film (310) includes acrylic resin; The surface of the base layer (200) comprises a metallic material.
8. The preparation method according to claim 1, characterized in that, The thickness of the first dry film (310) is not less than 20 micrometers and not more than 30 micrometers.
9. The preparation method according to claim 1, characterized in that, Also includes: Based on the dimension x of the first functional layer (402) along the first direction, the height d of the top step of the inner wall of the first through hole (301) being suspended, and the distance h from the first functional layer (402) to the vapor deposition source, the dimension c of the top step of the inner wall of the first through hole (301) along the first direction is determined; the first direction is parallel to the base layer (200); in, c <x; Based on the dimension c along the first direction at the top step of the inner wall of the first through hole (301), the dimension x along the first direction of the first functional layer (402), and the dimension a along the first direction at the bottom of the first through hole (301), the dimension b along the first direction at the secondary step from the top down of the inner wall of the first through hole (301) is determined. Where, x <b<a。 10. A semiconductor device, characterized in that, Prepared by any one of the preparation methods described in claims 1-9, comprising: Base layer (200); The first functional layer (402) is formed on the base layer (200).