Semiconductor device and manufacturing method

Abstract

The invention discloses a semiconductor device and a manufacturing method thereof, and belongs to the technical field of semiconductors. In order to solve the problems of poor pattern flexibility and high adjustment cost caused by complete dependence on a mask plate in the traditional photoetching process, the method comprises the following steps of: selectively coating a photo-acid quencher on an area in which photoresist needs to be reserved before post-baking the photoresist, and removing the photoresist by utilizing the elimination effect of the photo-acid quencher on photo-acid, so that the photoresist can be reserved in the area; therefore, the photoresist in the region is reserved due to no acid catalysis reaction in the subsequent process, so that the formed mask layer pattern is adjusted. Therefore, according to the manufacturing method provided by the invention, the mask pattern can be flexibly adjusted without manufacturing a new mask plate, the process flexibility is remarkably improved, and the cost is reduced.

Description

Technical Field

[0001] This application relates to semiconductor technology, specifically to a semiconductor device and its manufacturing method. Background Technology

[0002] In the manufacturing process of semiconductor devices, the mask layer is an important process structure for local processing of wafers. It can block part of the wafer surface and expose the part that needs to be processed, so as to realize local processing of the wafer (such as local etching, local doping, etc.).

[0003] A mask layer is generally based on a photoresist layer and a photomask. In the photoresist exposure process, the photomask is placed upstream of the exposure light path, so that the exposure range of the photoresist receiving the exposure beam is consistent with the light-transmitting area of ​​the photomask itself, realizing the pattern transfer between the photomask and the photoresist layer, thereby forming a mask layer.

[0004] Given that wafer local processing is related to the actual structure of the fabricated semiconductor device, adjusting the device structure often requires redesigning and manufacturing a photomask, resulting in significant production costs and hindering the adjustment and testing of the semiconductor device. Therefore, how to form a mask layer more flexibly is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, embodiments of this application provide a semiconductor device and manufacturing method, which removes photoacid in a specific area by using an exogenous photoacid quencher, thereby adjusting the area of ​​the photoresist layer that has been modified, and thus enabling the adjustment of the mask layer.

[0006] In a first aspect, this application provides a method for manufacturing a semiconductor device. The method includes at least the formation of a mask layer based on a photoacid quencher and partial wafer processing based on the mask layer. The formation of the mask layer based on the photoacid quencher includes: forming a photoresist layer on the surface of a substrate; performing an exposure process on the photoresist layer to modify a portion of the photoresist layer located within the exposure range to generate photoacid; coating a photoacid quencher on a reserved area of ​​the photoresist layer before a post-baking process to eliminate the photoacid in the reserved area; and performing a development process on the photoresist layer to remove the portion of the photoresist layer modified by the photoacid to form a mask layer, wherein the mask layer covers the reserved area.

[0007] Secondly, this application provides a semiconductor device including a first wafer and a second wafer, with a bonding structure pair mutually bonded between the first wafer and the second wafer. The bonding structure pair is formed based on the manufacturing method described in the first aspect, and a reserved region of a mask layer is configured based on the wafer edge region of the wafer, so that the bonding structure pair avoids the wafer edge regions of the first wafer and the second wafer during formation. The first wafer and the second wafer are mutually bonded through the bonding structure pair.

[0008] Based on the semiconductor device and manufacturing method provided in this application, to address the problems of poor pattern flexibility and high adjustment costs in traditional photolithography processes due to their complete reliance on photomasks, a photoacid quencher is selectively coated onto areas where photoresist needs to be retained before post-baking of the photoresist. Utilizing the photoacid quencher's elimination effect on photoacid, the photoresist in these areas is retained in subsequent processes because no acid-catalyzed reaction occurs, thereby adjusting the pattern of the formed mask layer. Therefore, the manufacturing method provided in this application allows for flexible adjustment of the mask pattern without the need to create a new photomask, significantly improving process flexibility and reducing costs. Attached Figure Description

[0009] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments 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.

[0010] Figure 1 This is a schematic diagram of the photoresist exposure and development process provided by the related technology of this application.

[0011] Figure 2 This is a schematic diagram of the photoresist layer exposure process provided in some embodiments of this application.

[0012] Figure 3 This is a schematic diagram of the development process of the photoresist layer based on a photoacid quencher provided in some embodiments of this application.

[0013] Figure 4 This is an exemplary flowchart of the mask layer formation process based on photoacid quenchers provided in some embodiments of this application.

[0014] Figure 5 This is an exemplary flowchart of a development process based on a photoacid quencher provided in some embodiments of this application.

[0015] Figure 6 This is a schematic diagram of the structure of a semiconductor device having at least two wafers and a bonding structure provided by the related technology of this application.

[0016] Figure 7 This is an exemplary flowchart of the semiconductor device fabrication process provided in some embodiments of this application.

[0017] Figure 8 This is an exemplary flowchart of the process for forming a wafer bonding structure that avoids the wafer edge region, as provided by the related technologies of this application.

[0018] Among them, 110 is the substrate; 120 is the photoresist layer; 121 is the exposure area; 122 is the unexposed area; 123 is the photoacid layer; 124 is the reserved area; 130 is the photomask; 131 is the light-transmitting area; 132 is the light-shielding area; 140 is the exposure light source; 600 is the semiconductor device; 610 is the first wafer; 620 is the second wafer; 630 is the bonding structure; 631 is the first bonding trench; 632 is the second bonding trench; 633 is the bonding medium; and 640 is the wafer edge region. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this application. Therefore, the drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the shape, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0021] In this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used only for descriptive and distinguishing purposes and should not be construed as indicating or implying relative importance.

[0022] Application Overview: Photoresist is a photosensitive mixed colloidal liquid. Based on its photosensitive properties, photoresist can be used as a mask layer in semiconductor devices to achieve localized wafer processing. Specifically, a mask layer is formed by the exposure and development process of photoresist. This mask layer covers part of the wafer surface and exposes part of the wafer. That is, part of the wafer is covered by the mask layer, and part of the wafer is exposed relative to the mask layer.

[0023] In semiconductor fabrication processes, localized wafer processing can be achieved using mask layers. For example, when a wafer surface is placed in an etching environment, the mask layer covering the wafer surface blocks the etching process. As a result, the morphology of the wafer surface covered by the mask layer remains unchanged, while the morphology of the wafer surface not covered by the mask layer is altered by etching (e.g., forming grooves, vias, etc.). Furthermore, surface doping processes can also be performed using mask layers to form semiconductor source and drain structures.

[0024] As mentioned above, the process of transferring photoresist to the mask layer depends on a photomask. A photomask typically includes a light-transmitting area and a light-shielding area. For example, a photomask can consist of a transparent substrate (quartz or glass) and an opaque light-shielding layer (usually a chromium film), with the light-shielding layer forming the shielding area.

[0025] In the photoresist exposure and development process, light shines through the light-transmitting area onto the substrate coated with photoresist, triggering a photochemical reaction (i.e., localized photomodification of the photoresist) to achieve pattern transfer. The pattern transfer process generally includes steps such as coating, pre-baking, alignment and exposure, post-baking, and development.

[0026] Specifically, coating refers to the uniform spin-coating of photoresist onto the surface of a silicon wafer to form a thin layer. Pre-bake removes the solvent used during coating, enhancing the adhesion between the photoresist and the substrate (such as a wafer). Alignment and exposure involve irradiating a photomask (printed with circuit patterns) with light of a specific wavelength, causing a photochemical reaction in the exposed area of ​​the photoresist. Post-exposure baking intensifies the chemical changes in the exposed area, improving pattern accuracy. Development is used to remove portions of the photoresist layer.

[0027] In the aforementioned process, the photoresist can be modified during exposure, thus manifesting as the corresponding image during subsequent development. The photoresist can include both positive and negative types. With positive photoresist, the solubility of the photoresist within the exposed area increases during exposure, and it is dissolved and removed during subsequent development. With negative photoresist, the photoresist within the exposed area is solidified during exposure and retained during subsequent development, while the photoresist in the unexposed area is dissolved and removed during development.

[0028] To further illustrate this point, this application also provides a schematic diagram of the photoresist exposure and development process. Figure 1 ).

[0029] like Figure 1As shown, photoresist can be formed on the surface of substrate 110 based on the aforementioned coating and pre-baking processes to form photoresist layer 120. Substrate 110 refers to a wafer undergoing partial wafer processing, a portion of a wafer, or the bonding result of multiple wafers. The surface of substrate 110 can refer to the side of the wafer undergoing partial wafer processing; for example, in a doping process, the surface of substrate 110 can be the side of the wafer where the source and drain electrodes are formed.

[0030] In the alignment exposure process, the photomask 130 can be aligned with the photoresist layer and positioned upstream of the photoresist layer 120 along the exposure optical path. As mentioned above, the photomask 130 includes a light-transmitting region 131 and a light-shielding region 132. The light-transmitting region 131 is a light-transmitting substrate without a light-shielding layer, and the light-shielding region 132 is a light-transmitting substrate covered with a light-shielding layer.

[0031] Based on the light-transmitting region 131 and light-shielding region 132 of the aforementioned photomask 130, an exposure range 121 and an unexposed range 122 can be formed in the photoresist layer 120. The exposure range 121 refers to the portion of the photoresist layer 120 that is not blocked by the photomask 130 in the exposure optical path and corresponds to the light-transmitting region 131; the unexposed range 122 refers to the portion of the photoresist layer 120 that is blocked by the photomask 130 in the exposure optical path and corresponds to the light-shielding region 132.

[0032] In the exposure process, the exposure beam emitted by the exposure light source 140 propagates onto the photoresist layer 120. Specifically, the exposure beam directed toward the exposure range 121 propagates onto the photoresist layer 120 without obstruction, causing the photoresist in the exposure range 121 to change; while the exposure beam directed toward the unexposed range 122 is blocked by the photomask 130, so that the properties of the photoresist layer 120 in the unexposed range 122 remain unchanged.

[0033] Taking positive photoresist as an example, most advanced positive photoresists rely on photoacid-driven chemical amplification reactions to achieve patterning. Specifically, in photoresist layer 120, photoacid-generating agents (such as sulfonium salts and iodonium salts) decompose after absorbing photons, releasing strongly acidic molecules (such as sulfonic acid H₂). + ).

[0034] Based on the aforementioned modified photoresist layer 120, in the subsequent post-baking process, the photoacid in the photoresist layer 120 of the exposure area 121 diffuses into the resin molecular chain during the post-baking stage, catalyzing the removal of protecting groups (such as tert-butyloxycarbonyl t-BOC). Subsequently, in the subsequent development process, the resin after the protecting groups are removed dissolves in an alkaline developer (such as 2.38% TMAH), causing the photoresist layer corresponding to the exposure area 121 to be removed, forming the same pattern as the photomask 130.

[0035] In addition, positive photoresist can also be a traditional DNQ-phenolic resin positive photoresist, based on carboxylic acid denaturation to remove the photoresist layer in the exposure range 121.

[0036] Based on the foregoing Figure 1 The photoresist patterning process shown illustrates that the patterning of the photoresist itself depends on the structure of the photomask. Adjustments to semiconductor devices often require the fabrication of a new photomask (i.e., redistribution of the mask's light-shielding layer), a process that incurs significant production costs. This is especially true when test results are unsatisfactory, often necessitating multiple tests.

[0037] Based on the aforementioned masking logic of the photoresist layer itself, this application creatively discovers that in the critical stage before post-baking, it is no longer necessary to rely entirely on the pattern defined by the photomask at the moment of exposure. Instead, by introducing exogenous chemical reagents to intervene in the photoacid activity of specific areas, the final developed pattern can be actively adjusted.

[0038] Specifically, photoacids play an indispensable catalytic role in the chemical amplification reaction mechanism of positive photoresists. Their mechanism can be further explained as follows: the initial photoacids (also known as latent image acids) generated during the exposure step are relatively limited in quantity; however, in the subsequent post-bake (PEB) process, these initial photoacids trigger a chain reaction (i.e., a chemical amplification process), catalyzing chemical reactions such as deprotection of photoresist resin molecules, thereby generating a large number of chemical groups within the exposure range that allow the photoresist to dissolve in the developer. It is precisely through the post-bake treatment that the initial photoacids catalyze the deprotection reaction of photoresist resin molecules, chain-generating a large amount of photoacids. These photoacids penetrate the corresponding photoresist layer within the range of the initial photoacids, ultimately determining the dissolution behavior of the photoresist in the development step.

[0039] Therefore, this application demonstrates that if the photoacids in a specific region can be selectively deactivated (i.e., "quenched") before this chemical amplification process occurs (i.e., before post-baking), the chain reaction in that region can be blocked. This means that even if the region has been exposed, the photoacids within it will be quenched without undergoing sufficient chemical modification during post-baking, thus allowing the region to remain in the developer. Conversely, in regions where photoacid quenching has not been performed, the photoacid catalysis will proceed smoothly, and the photoresist will be removed during development.

[0040] Based on this principle, by flexibly defining the retention areas requiring photo-acid quenching on the photoresist layer and applying the corresponding photo-acid quencher, it is possible to perform supplementary or corrective pattern adjustments based on existing photomask patterns, and even achieve maskless patterning processes under specific conditions. This greatly enhances the flexibility of mask layer fabrication and provides new avenues for the design and optimization of semiconductor devices.

[0041] To more intuitively illustrate the core idea of ​​this invention—achieving pattern adjustment through photo-acid quenching—this application also describes the exposure process of the photoresist layer ( Figure 2 ) and the development process based on photoacid quenchers ( Figure 3 A diagram is provided.

[0042] Further explanation Figure 2 and Figure 3 Before the process shown, the aforementioned photoacid action mechanism is first applied to the aforementioned... Figure 1 The exposure range 121 shown will be explained in more detail.

[0043] Based on the aforementioned mechanism of photoacids in the positive photoresist layer, when the exposure area 121 is exposed to light, the photoacid-generating agent inside it decomposes, generating initial photoacids. After post-baking, these initial photoacids catalyze chemical changes in the photoresist resin (such as deprotection reactions), making the photoresist in that area soluble in the developer. Therefore, in conventional processes, the exposure area 121 is eventually removed after development, exposing the surface of the underlying substrate 110.

[0044] Specifically, please see Figure 2 When the exposure beam reaches the surface of the exposure area 121, it can form a photoacid layer 123 on the surface of the exposure area 121. This photoacid layer 123 diffuses within the exposure area 121 after a post-baking process. Figure 1 The exposure range shown is 121, which is filled with photoacid. It should be noted that... Figure 2 The mid-surface is just one example of initial photoacid formation; photoacid generally forms within the area focused by the exposure beam in the exposure range 121. The surface photoacid concentration is higher, while the concentration is lower in the interior (e.g., the bottom).

[0045] However, this application finds that this process is not irreversible. The activity of photoacid, as a catalyst for the chemical reaction, is decisive. Before post-baking, an exogenous photoacid quencher is selectively applied to the area to which it is intended to be retained as a mask (denoted as the retention area). The photoacid quencher penetrates into the photoresist layer and reacts with the initial photoacid that has been generated, deactivating it.

[0046] like Figure 3 As shown, after the exposure process, a portion of the area within the exposure range 121 is designated as a retention area 124, which is occupied by a photoacid quencher but does not contain photoacid. Other areas are occupied by photoacid, allowing the photoacid layer 123 to penetrate the area outside the retention area 124 within the exposure range 121. It should be noted that, considering the photoacid quenching performed before the post-baking process in this application, the aforementioned retention area 124, due to the action of the photoacid quencher, only retains the initial photoacid for the chain reaction in a portion of the area, without allowing the photoacid to penetrate the entire area.

[0047] The formation of the aforementioned photoacid layer 123 alters the properties of the photoresist, making the photoresist layer containing the photoacid soluble during the development process. Figure 3 The retained area 124 and the unexposed area 122 are insoluble in the developing process because they do not contain photoacid.

[0048] Therefore, in the development process, not all of the original exposed area 121 is removed. Only those parts that were not covered by the photoacid quencher and underwent a sufficient acid catalytic reaction are dissolved; while the photoresist in the retained area 124, although it was also exposed, is preserved intact like the unexposed area 122 because the photoacid was quenched in advance, and together with it, it forms the final mask layer.

[0049] It is evident that by controlling the position and extent of the photo-acid quencher coating, the photoresist pattern that needs to be retained can be actively "drawn," thereby achieving pattern control with far greater flexibility than traditional photomasks. Figure 2 and Figure 3 It clearly demonstrates the complete process from "chemical intervention" to "graphic reshaping".

[0050] It should be noted that, to achieve the aforementioned purpose of modifying the mask layer, the aforementioned photoacid quencher can be applied before the post-baking process. Specifically, during the post-baking process, the initial photoacid will trigger a chain reaction catalyzing the deprotection reaction, generating a large amount of photoacid. The deprotection reaction removes hydrophobic groups, exposing hydrophilic polar functional groups (such as -OH) on the polymer backbone. These hydrophilic groups will react with the alkali in the developer solution during the subsequent developing process and rapidly dissolve in the developer solution. Therefore, the initial photoacid at the source should be quenched before the deprotection reaction is performed.

[0051] In a preferred embodiment, the coating of the photoacid quencher is performed after the exposure process and before the post-baking treatment. This optimal timing results in particularly significant technical effects.

[0052] Specifically, before the post-baking process, the initial photoacids generated during exposure have not yet begun large-scale diffusion and chain catalytic reactions, and their distribution is relatively concentrated near the exposure site. At this time, the introduction of photoacid quenchers can directly act on these initial photoacid molecules with high efficiency and certainty, almost completely neutralizing or eliminating their catalytic activity in the retention region 124, thereby most thoroughly blocking the subsequent chemical amplification process.

[0053] In addition, photoacid quenchers can also be applied before the exposure process. In this case, during the subsequent exposure process, the initial photoacid formed during exposure will be quenched by the residual photoacid quencher during its formation, preventing it from remaining in the subsequent post-baking process.

[0054] It is evident that by precisely controlling the position and range of the photo-acid quencher coating and prioritizing the key timing before post-baking, the photoresist pattern that needs to be retained can be actively and accurately "drawn," thereby achieving pattern control with far greater flexibility than traditional photomasks.

[0055] Based on the aforementioned development and exposure process, the following will combine... Figures 4-8 The manufacturing method of the semiconductor device provided in this application is described in detail.

[0056] Exemplary mask layer formation method: Based on the aforementioned photoresist etching process using photoacid quenchers, at least one of the aforementioned mask layer formation processes based on photoacid quenchers can be performed during the fabrication of semiconductor devices, thereby enabling local wafer processing processes (such as local etching and local doping) based on the mask layer to complete the fabrication of semiconductor devices.

[0057] To further illustrate the mask layer formation process based on photoacid quenchers, this application also provides an exemplary flowchart of the mask layer formation process based on photoacid quenchers ( Figure 4 ).

[0058] like Figure 4 As shown, process P400 may include the following steps: S410, A photoresist layer is formed on the surface of the substrate.

[0059] S420. Perform an exposure process on the photoresist layer so that the portion of the photoresist layer located within the exposure range is exposed and modified to generate photoacid.

[0060] S430. Before post-baking, apply a photoacid quencher to the reserved area of ​​the photoresist layer to eliminate photoacid in the reserved area.

[0061] S440. Perform a development process on the photoresist layer to remove part of the photoresist layer that has been photo-modified to form a mask layer.

[0062] In the aforementioned S410, the substrate can refer to the object substrate that requires patterning local processing. Specifically, the substrate, as the carrier of the semiconductor device structure, provides the physical basis for photolithography processes. In practical applications, the substrate can encompass a complete wafer, a semi-finished wafer that has completed some manufacturing processes (such as deposition and etching), or a stacked structure formed by bonding multiple wafers. The surface specifically refers to the side of the substrate where this local processing (such as etching to form bonding trenches) will be performed.

[0063] A photoresist layer refers to a thin film of polymer coated on the surface of a substrate, which is sensitive to light of a specific wavelength and therefore undergoes chemical changes. It serves as a medium for temporary pattern transfer. Based on the aforementioned mechanism, in this application, the photoresist layer specifically refers to a thin film layer formed by a positive photoresist employing a chemical amplification mechanism. In practical applications, the technical principles of this application can also be adapted to negative photoresists.

[0064] In some embodiments, S410 can refer to all operations of preparing a photoresist film on the substrate surface that meets the process requirements. In practical applications, S410 can be achieved by spin coating. This involves dropping an appropriate amount of photoresist onto the substrate surface, then rotating the substrate at high speed to use centrifugal force to evenly spread the photoresist and remove excess photoresist, thereby forming a film of a predetermined thickness. Subsequently, a pre-baking (soft drying) step is often required to remove residual solvents from the coating and enhance the adhesion between the photoresist and the substrate surface.

[0065] In the aforementioned S420, exposure processing refers to the process step of irradiating a formed photoresist layer with light of a specific wavelength to induce a photochemical reaction. Specifically, exposure processing is used to excite sensitive components within the photoresist using light energy, thereby generating a latent image. In practical applications, exposure processing also involves a photomask. That is, exposure processing can refer to the process of selectively irradiating the photoresist layer using an ultraviolet light source through a photomask with a defined target pattern. Furthermore, based on the aforementioned principle, the photoacid formed during exposure processing often acts as a "seed" that diffuses throughout the corresponding area of ​​the photoresist layer during subsequent baking. The photoacid formed during exposure processing can be referred to as the initial photoacid.

[0066] The exposure range refers to the area on the photoresist layer surface actually covered by the exposure beam during the exposure process. Its specific range is determined by the photomask and can be represented as the area of ​​the photoresist layer surface exposed relative to the photomask. Since the photoresist layer surface within the exposure range is exposed relative to the photomask, the exposure beam emitted by the exposure source can reach the exposure range of the photoresist surface through the photomask, thereby modifying the photoresist in that area through exposure.

[0067] Exposure modification refers to the chemical changes that occur in the photoresist layer due to exposure treatment. In the positive chemical amplification photoresist involved in this application, exposure modification can refer to the situation where the photoacid-generating agent in the photoresist decomposes after absorbing photons, producing acidic substances (photoacids). That is, the photoresist layer within the aforementioned exposure range is modified by exposure, resulting in the formation of photoacids within it.

[0068] The aforementioned S420 can refer to a series of operations involving selective exposure of a photoresist layer using a photomask. In practical applications, to achieve S420, the substrate coated with the photoresist layer is typically precisely aligned with the photomask, and then irradiated with an ultraviolet light source. The exposure beam passes through the light-transmitting area of ​​the photomask, triggering a photochemical reaction in the corresponding area of ​​the photoresist (i.e., exposure modification to produce photoacids).

[0069] It should be noted that the aforementioned S420 reflects the image transfer process based on the original photomask. The determined exposure range strictly corresponds to the photomask. Continuing the development process after this step directly forms a mask layer that strictly corresponds to the photomask. However, in this application, to achieve the subsequent removal of some photoacids within the exposure range, a retention area free of photoacids is constructed within the exposure range, thereby changing the range of the photoresist layer remaining after development.

[0070] In the aforementioned S430, the retained area can refer to a specific region within the exposure range where the photoresist needs to be retained rather than removed in the subsequent development process. Based on the implementation process in the aforementioned S420, the retained area can be understood as an actively defined region used to correct the initial exposure pattern. It is characterized by being a region treated by subsequently coating with a photoacid quencher to block the post-baking and development processes in that region, thereby retaining the desired additional pattern in the final mask layer.

[0071] It should be noted that the shape and position of the reserved area can be flexibly determined according to the device design requirements, and do not necessarily have a geometric relationship with the exposure range or the pattern of the photomask. For example, in subsequent wafer bonding scenarios, the reserved area can be configured as the edge region of the wafer.

[0072] Post-exposure baking (PEB) specifically refers to the process of baking after exposure, which promotes chemical changes within the photoresist through heat treatment. Based on the aforementioned principle, post-exposure baking allows the initial photoacids to diffuse under heat and catalyzes deprotection reactions in the photoresist polymer, exposing hydrophilic polar functional groups on the polymer backbone. This allows the photoresist layer containing the photoacids to be dissolved by subsequent development processes.

[0073] Photocatalytic acid quenchers can refer to a class of chemical substances that can deactivate photocatalytic acids through chemical reactions. Essentially, they deactivate photocatalytic acids. In this application, photocatalytic acid quenchers may include reagents capable of undergoing neutralization, complexation, or reductive oxidation reactions with photocatalytic acids.

[0074] Based on the aforementioned principles, to prevent the aforementioned deprotection reactions from occurring in the retained area, the S430 process can be performed entirely before the post-baking process. That is, the photo-acid quencher can be coated before the post-baking process. Coating the photo-acid quencher refers to the operation of applying a certain amount of photo-acid quencher to a specific surface of the photoresist layer. In practical applications, the coating of the photo-acid quencher can be achieved through various methods such as spraying, spin coating, and inkjet printing, depending on the device requirements.

[0075] Based on the aforementioned coating of photoacid quenchers, the photoacid quenchers can penetrate into the photoresist to eliminate photoacids within the retained regions. Eliminating photoacids within the retained regions can refer to the photoacid quenchers chemically removing or inactivating catalytically active substances within the target region. That is, the photoacid quenchers react with the photoacids generated during exposure, causing them to lose their ability to catalyze the deprotection or crosslinking reactions of the polymer.

[0076] The aforementioned S430 is a key operation for selectively applying a photoacid quencher to the photoresist layer to locally alter its chemical state. To achieve S430, it is typically necessary to first determine the pattern of the retention area, and then use an appropriate coating technique to precisely apply the prepared photoacid quencher solution to that area. This allows for the creation of a new retention area, unaffected by the initial exposure effect, based on the initial pattern defined by the photomask, through external chemical intervention. This enables secondary design or modification of the mask layer pattern, greatly improving process flexibility.

[0077] For example, even if the entire wafer is exposed, by coating only the outer periphery of the bonding structure area with a photoacid quencher, the photoresist in the bonding structure area can be removed (for etching) while the photoresist in the outer periphery area is retained (for protection), which cannot be achieved directly with a single fixed mask.

[0078] As described above, S430 can be performed before the post-baking process. In some embodiments, it can be performed after the exposure process and before the post-baking process. In this case, the initial photoacid formed in the retained area during the exposure process is removed by the photoacid quencher. For the exposure area not protected by the photoacid quencher, the post-baking process can cause the initial photoacid in the area to diffuse due to heat and catalyze the deprotection reaction (i.e., the chemical amplification process) of the photoresist polymer, exposing the hydrophilic polar functional groups on the polymer backbone, resulting in a significant increase in the solubility of the photoresist in that area. As for the retained area coated with the photoacid quencher, since the initial photoacid in the area has been effectively eliminated, the subsequent baking process cannot trigger an effective acid-catalyzed chain reaction, and the solubility of the photoresist in that area remains unchanged.

[0079] In addition to being performed after subsequent exposure processes and before post-baking, the aforementioned S430 can also be performed before the exposure process. This allows the photoacid quencher in the retained area to directly prevent the formation of photoacid at its source during development. During post-baking, the portion of the exposed area outside the retained area is completely modified and can be removed during development. The retained area, because no photoacid is generated (which can also be understood as being removed during photoacid formation), cannot trigger an effective acid-catalyzed chain reaction during this post-baking process, and the solubility of the photoresist in this area remains unchanged.

[0080] In the aforementioned S440, the development process refers to a step in which the photoresist layer, after exposure and subsequent processing, is selectively dissolved using a specific chemical reagent (developer). The development process achieves the final transfer of the pattern through differences in solubility. For positive photoresist layers, in practical applications, an alkaline aqueous solution (such as tetramethylammonium hydroxide TMAH solution) can be used to treat the photoresist layer to dissolve the portion whose solubility has increased due to chemical modification caused by the presence of photoacids.

[0081] The photoresist layer modified by photoacid can specifically refer to those regions within the photoresist layer that have undergone effective acid-catalyzed reactions (such as deprotection reactions). Based on the aforementioned treatment, it can reflect the portion outside the retention area within the exposure range. That is, based on the aforementioned photoacid quencher, the photoacid in the exposed retention area is deactivated, thereby preventing its solubility from increasing due to the photoacid formation process, and thus allowing it to be retained along with the areas where no photoacid has formed.

[0082] The mask layer can refer to the photoresist pattern that remains on the substrate surface after development, and can be used as a barrier layer for subsequent local wafer processing. Based on the aforementioned development exposure involving photoacid quenchers, its pattern can be the result of the combined effect of the pattern defined by the photomask and the "reserved area" pattern defined by the photoacid quencher.

[0083] The aforementioned S440 refers to a series of operations that selectively remove the modified portions of the photoresist layer using a developing solution to form the final mask pattern. In practical applications, to achieve S440, the substrate treated in S410 to S430 is typically immersed in the developing solution or sprayed with the developing solution at a certain flow rate. At this time, the photoresist in the exposed areas (i.e., the areas where the photoacid normally exerts its catalytic effect) not protected by the photoacid quencher is dissolved and removed, while the photoresist in the retained areas (where the photoacid is eliminated) and the unexposed areas remains due to its low solubility. Through the aforementioned S440, the chemical state difference can be transformed into a physical topological structure, forming a mask layer that can be used for subsequent etching or ion implantation processes. For example, after approximately 60 seconds of development, rinsing with deionized water and spin-drying yields a patterned mask layer containing the pattern defined by the original mask and the additional pattern retained by the photoacid quencher.

[0084] Therefore, to address the problems of poor pattern flexibility and high adjustment costs inherent in traditional photolithography processes due to their complete reliance on photomasks, the photomask layer formation process based on photoacid quenchers, as described in P400, selectively coats the areas where photoresist needs to be retained with a photoacid quencher and utilizes the quencher's ability to eliminate photoacid. This ensures that the photoresist in these areas is retained in subsequent processes because no acid-catalyzed reaction occurs, thereby adjusting the pattern of the formed photomask layer. Consequently, the manufacturing method provided in this application allows for flexible adjustment of the photomask pattern without the need to create a new photomask, significantly improving process flexibility and reducing costs.

[0085] It should be noted that in the process described in P400 above, the photoacid quencher only needs to quench the photoacid in the retained area before the post-baking process, and the specific application process is not limited. For example, the photoacid quencher can be applied directly after the photoresist is formed, and directly suppress the formation of photoacid in the retained area during exposure. As another example, the photoacid quencher can be applied before the post-baking process to eliminate surface photoacid formed during the exposure process. For the discussion before exposure, please refer to the relevant description in S430 above, while for the discussion after exposure and before post-baking, please refer to... Figure 5 And its related descriptions.

[0086] Furthermore, as mentioned above Figures 1-3 The description of the exposure and development process states that, to reduce the impact of photoacids, the aforementioned photoacid quencher can be applied after the exposure process but before the post-baking process. To further illustrate this process, this application also provides an exemplary flowchart of a development process based on a photoacid quencher (…). Figure 5 ).

[0087] like Figure 5 As shown. The development process P500 based on photoacid quenchers may include the following steps: S510. Perform an exposure process on the photoresist layer to form initial photoacids on the surfaces of the photoresist layer located within the exposure range.

[0088] S520. Apply a photoacid quencher to the reserved area so that the photoacid quencher can penetrate into the reserved area and eliminate the initial photoacid in the reserved area.

[0089] S530, Perform post-bake treatment on the photoresist layer.

[0090] In the aforementioned S510, the meaning of exposure processing can be the same as that in the aforementioned S420. The photoacid formed by the exposure processing is mainly formed on the surface of the photoresist layer within the exposure range. The photoacid formation inside is insufficient, and a post-baking process is required to allow the photoacid to diffuse longitudinally to the complete photoresist layer.

[0091] Based on the different treatments of photoacid by exposure and post-baking mentioned above, the photoacid generated by exposure treatment in the aforementioned P500 can be referred to as the initial photoacid.

[0092] Specifically, the initial photoacid is generated instantaneously during the exposure process, and spatially it is mainly distributed on the surface of the photoresist exposed to light and part of its interior. Therefore, the amount of initial photoacid is relatively small, serving as the "seed" or starting point for the chemically amplified reaction. Simultaneously, the initial photoacid itself already possesses catalytic activity, but its catalytic effect has not yet been fully utilized to significantly alter the chemical properties of the large-area photoresist.

[0093] In the aforementioned S520, the coating of the photoacid quencher can be performed after exposure and before post-baking. That is, the exposure process referred to in S510 can form an initial photoacid layer on the surface of the photoresist layer within the exposure range, and the subsequent post-baking process referred to in S530 can longitudinally diffuse the initial photoacid on the surface to cover the photoresist layer. Performing the coating of the photoacid quencher between these two processes can eliminate the initial photoacid, preventing it from initiating a chain catalytic reaction in the post-baking process in the subsequent S530 (within the reserved area).

[0094] In some embodiments, the aforementioned S520 may refer to a refined operation of coating a photoacid quencher onto a designated retention area after exposure and before post-baking. To achieve the goal of penetrating the interior and eliminating photoacid, the photoacid quencher formulation used is typically required to effectively wet the photoresist surface and diffuse inwards. For example, the quencher solution can be locally applied to the target area (e.g., wafer edge) at room temperature using a precisely controlled spray or drop-coating system, maintaining a certain residence time (e.g., 30-120 seconds) to ensure that the reagent fully penetrates into the photoresist film and reacts with the initial photoacid.

[0095] In the aforementioned S530, driven by heat, the "initial photoacid" initially distributed on the surface diffuses into the depth of the photoresist layer, simultaneously catalyzing the deprotection reaction along its path and generating more new acids; this reaction can be a chain reaction. Based on the photoacid quencher pre-arranged inside the photoresist layer, the diffusion of this photoacid occurs only longitudinally, so that the photoacid after the chain reaction penetrates the photoresist layer based on the position of the remaining initial photoacid.

[0096] The aforementioned S530 can refer to the process of heating a substrate that has been exposed and coated with photoacid quencher at a specific temperature (e.g., 90-130 degrees Celsius) for a specific time (e.g., 60-120 seconds). This operation is typically carried out on a hot plate or in an oven to utilize thermal energy to activate and complete the photoacid-driven chemical amplification reaction, thereby microscopically "curing" the pattern information determined by S510 (exposure definition) and S520 (quencher correction).

[0097] In some embodiments, considering that the photo-acid quencher applied in step S520 may still partially remain on the photoresist layer surface after quenching, thus affecting subsequent steps, the photoresist layer can be cleaned before performing step S530 to remove residual photo-acid quencher. Therefore, step P500 further includes the following between steps S520 and S530: S525. Perform a surface cleaning process on the photoresist layer to remove residual photoacid quenchers on the surface of the photoresist layer.

[0098] In the aforementioned S525, the "surface cleaning process" refers to the operation of removing excess material remaining on the surface of the photoresist layer to maintain interface cleanliness, ensuring that subsequent process steps are not interfered with by residues from previous processes. Specifically, S525 can prevent residual photoacid quenchers on the surface from undergoing thermal decomposition or generating byproducts during the subsequent high-temperature post-baking process (S530). These byproducts may contaminate the process chamber or affect the performance of the photoresist itself. In addition, it can also ensure the uniformity of the photoresist surface state, avoiding any negative impact of residues on subsequent processes (such as uniform contact of the developer).

[0099] In some embodiments, the aforementioned S525 can be achieved through a gentle rinsing and drying process. To achieve effective cleaning without damaging the formed photoresist pattern or affecting the completed internal quenching effect, a low surface tension solvent can be used for rapid rinsing, followed by drying. For example, anhydrous ethanol or a specific organic solvent can be used to rinse the substrate surface, followed by high-speed spin drying or purging the surface with an inert gas (such as nitrogen) to ensure that the photoresist layer surface is clean and dry, preparing it for subsequent post-baking processes.

[0100] The actual use of photo-acid quenchers in the manufacturing process has been described in detail above. The following will explain the actual use in conjunction with the above description.

[0101] Based on the aforementioned photoacid quenching agents' ability to eliminate photoacids, these agents can generally be presented as mixed reagents loaded with effective components for quenching photoacids. Their specific type can be determined based on the actual scenario of photoacid elimination. For example, in the case of photoacid elimination before the aforementioned exposure process, the photoacid quencher can be dissolved in a gel-like reagent to ensure a continuous supply of photoacid quencher to the photoresist surface to eliminate initial photoacids.

[0102] When performing photoacid removal after exposure and before post-baking, it is important to consider that the initial photoacid does not only remain on the surface of the photoresist, but has penetrated to a certain depth within the photoresist film at the moment of exposure (at least the depth of the initial photoacid). In this case, the photoacid quencher should be soluble in or highly compatible with the photoresist layer.

[0103] Therefore, photoacid quenchers can be contained in liquid solvents. Considering the low polarity of the photoresist layer itself, to ensure that the photoacid quencher can penetrate into the photoresist, the reagent system can have low / medium polarity and non-repulsive polarity with the photoresist layer, so that the effective components can effectively diffuse from the coating point into the interior of the photoresist layer and reach the location of the photoacid. In other words, the photoacid quencher is a low-polarity substance that is non-repulsive to the polarity of the photoresist layer, capable of diffusing into the interior of the photoresist layer and eliminating photoacid.

[0104] The quencher molecules themselves have good compatibility or a certain affinity with the photoresist polymer matrix, and are not easily driven away by the post-baking process. At the same time, the solvent used should also have the property of being able to diffuse within the photoresist, together forming a stable diffusion and residence system. Organic base quenchers based on the principle of acid-base neutralization are characterized by rapid reaction and simple products. The effective component (i.e., quenching molecule) of photoacid quenchers can be selected from basic reagents that eliminate photoacids based on acid-base neutralization reactions.

[0105] Therefore, photoacid quenchers can be formulated as organic bases with a molecular weight smaller than the grid size of the photoresist layer and a polarity similar to that of the photoresist layer, thereby eliminating photoacids based on the principle of acid-base neutralization. The liquid solvent carrying the photoacid quencher should also have a similar polarity to the photoacid quencher (i.e., possess low polarity characteristics that do not repel the polarity of the photoresist) to ensure its complete dissolution in the reagent.

[0106] Considering that photoresist forms a cross-linked polymer network with a specific mesh structure after curing, if the quencher molecule size is too large, far exceeding the free volume pore size of the photoresist network, it will be physically blocked and unable to effectively diffuse to the action site. Therefore, it is necessary to select a quencher with a sufficiently small molecular weight to ensure that it can smoothly penetrate the spatial mesh barrier of the photoresist and freely diffuse into the entire volume that needs to be protected.

[0107] Preferably, a low-polarity organic amine with a molecular weight of less than 300 Daltons, such as triethylamine or diethylamine, can be selected. Due to their small molecular size and low-polarity properties that do not repel the photoresist polarity, these substances can enter the photoresist and neutralize and eliminate photoacids.

[0108] In addition to the aforementioned main components, to optimize penetration efficiency and ensure the quencher solution spreads rapidly and uniformly on the photoresist surface, maximizing its diffusion inwards, the reagent may also include other auxiliary components (mainly surfactants and stabilizers). Surfactants significantly reduce the surface tension of the solution, improve its wettability on the hydrophobic photoresist surface, and prevent droplet shrinkage, thereby providing a larger effective contact area and a better diffusion path for the quencher molecules. Simultaneously, the addition of stabilizers aims to prevent the organic amine active ingredients from oxidizing and deteriorating during preparation or storage, ensuring the long-term stability and process reproducibility of the reagent system.

[0109] Based on the above findings and solutions, this application also provides a specific and effective implementation method involving a particular combination of reagents. The photoacid quencher is preferably triethylamine (TEA) or diethylamine (DEA), with a molecular weight much less than 300 Daltons, exhibiting good diffusivity and moderate alkalinity. The liquid solvent is preferably low-polarity ethanol, isopropanol, or propylene glycol methyl ether acetate (PGMEA) to ensure compatibility with the photoresist.

[0110] To further enhance performance, the solution may also contain 0.01% to 0.1% of a fluorocarbon or siloxane surfactant to promote diffusion, and 0.01% to 0.1% of a stabilizer such as BHT (butylated hydroxytoluene) to prevent oxidation of the amine component. For example, a specific formulation may contain about 0.5% triethylamine, about 0.05% fluorocarbon surfactant, about 0.05% BHT, and the remainder ethanol.

[0111] Based on the above description, this application fully illustrates the adjustment of photoresist based on photoacid quenchers during semiconductor device manufacturing and the selection of photoacid quenchers in this process.

[0112] Exemplary semiconductor devices and methods for manufacturing the same: This application discovers that during bonding, the bonding structure at the wafer edge may fail to bond or form bubble defects. Based on the aforementioned mask layer formation process, by coating the wafer edge region with a photo-acid quencher, the wafer bonding structure can be formed outside the wafer edge, thereby avoiding bubble defects in the wafer bonding structure caused by the wafer edge region.

[0113] The wafer bonding involved in the aforementioned situation (mainly involving hybrid bonding) is a three-dimensional wafer integration technology that enables vertical stacking and interconnection of wafers. It is primarily used in stacked image sensors (CIS), 3D NAND memory, high-performance processors, and MEMS (microelectromechanical systems).

[0114] Taking a back-illuminated image sensor as an example, a pixel array wafer and a logic processing wafer can be bonded using wafer bonding technology. Specifically, the pixel array wafer can include a pixel layer (generally including pixel photosensitive units, such as photodiodes, color filters, etc.) and a metal interconnect layer. The logic processing wafer can include a logic circuit layer (such as an integrated ADC, signal processor, control circuit, etc., used to realize photoelectric signal conversion and processing) and a metal interconnect layer. Bonding grooves can be formed on the surfaces of the pixel array wafer and the logic processing wafer near the metal interconnect layer. The interconnection of the metal interconnect layers in the two wafers is achieved through the alignment of the bonding grooves and the bonding medium, thereby realizing the driving of the pixel layer by the logic circuit layer.

[0115] To further illustrate the cause of bubble defects appearing at the wafer edge in the aforementioned wafer bonding technology, this application provides a schematic diagram of a semiconductor device having at least two wafers and their bonding structure. Figure 6 ).

[0116] like Figure 6 As shown, the semiconductor device 600 may include a first wafer 610 and a second wafer 620 bonded together. The first wafer 610 and the second wafer 620 may represent two wafers bonded together, such as the aforementioned pixel array wafer serving as the aforementioned first wafer 610, and the aforementioned logic processing wafer serving as the aforementioned second wafer 620.

[0117] To achieve bonding between the first wafer 610 and the second wafer 620, multiple bonding structures 630 are formed at the contact interface between the first wafer 610 and the second wafer 620. The bonding structures 630 are formed by aligning bonding grooves and interconnecting bonding media within the bonding grooves. Specifically, the bonding structure 630 may include a first bonding groove 631 formed on the surface of the first wafer 610 facing the second wafer 620, a second bonding groove 632 formed on the surface of the second wafer 620 facing the first wafer 610, and bonding media 633 filling the first bonding groove 631 and the second bonding groove 632.

[0118] During bonding, the first bonding groove 631 and the second bonding groove 632 can be filled with bonding media (generally metallic media). Then, in a vacuum or inert gas (such as N2) environment, the first bonding groove 631 and the second bonding groove 632 are aligned and the two wafers are bonded together. Plasma treatment and hydrogen bonding are used to promote bonding between the two wafers, and heat curing (heating temperature 300-400℃) promotes atomic diffusion at the metallic media interface, causing the bonding media in the first bonding groove 631 and the second bonding groove 632 to fuse and interconnect at the interface, thereby forming a bonding structure 630.

[0119] During the aforementioned bonding process, the interface between the first bonding trench 631 and the second bonding trench 632 often needs to be in close contact to expel air, which places requirements on the flatness of the wafer surface. Specifically, before bonding, the surfaces of the first wafer 610 and the second wafer 620 to be bonded need to be mirror-polished and thoroughly cleaned to remove particles, organic matter, and metallic impurities, so that the surfaces of the first wafer 610 and the second wafer 620 to be bonded have a flat appearance, thereby expelling gases from the environment at the interface between the first bonding trench 631 and the second bonding trench 632.

[0120] However, the wafer edge region 640 often requires an edge washing process before bonding. If a bonding trench is formed within the edge washing process area, the edge washing process will cause the bonding medium filled in the bonding trench to be consumed by the edge washing process reaction, thereby causing at least part of the medium to be lost from the surface of the bonding medium filled in the bonding trench, making its morphology unable to completely match the bonding medium on the other side. As a result, in subsequent bonding steps, the bonding trench in the area covered by the edge washing process is difficult to bond, and even if it is bonded, it may form a void structure due to the loss of medium.

[0121] Considering that the bonding trenches of the bonding structure 630 are often formed through wafer etching based on a mask layer, based on the aforementioned mask layer formation method, a mask layer can be formed based on the wafer edge region 640 during the wafer etching process, preventing the bonding structure 630 from forming in the wafer edge region 640. This avoidance measure can mitigate bubble defects that occur when the bonding structure 630 forms in the wafer edge region 640, thereby improving the performance of the semiconductor device.

[0122] In summary, during wafer bonding in related technologies, bubble defects may exist in the bonding structure 630 at the wafer edge region 640 due to the need for an edge washing process. This situation can be seen in [reference needed]. Figure 6 The bonding structure 630 is located within the left-hand wafer edge region 640. For cases where the bonding structure is not placed in the wafer edge region 640, please refer to [reference needed]. Figure 6 The right edge region of the wafer, 640. Additionally, the normal bonding structure 630 can be found in [reference needed]. Figure 6 The bonding structure in the middle is 630.

[0123] To further illustrate the process of avoiding bonding structures in the wafer edge region, this application also provides an exemplary flowchart of a semiconductor device manufacturing method (…). Figure 7 ).

[0124] like Figure 7 As shown, process P700 may include the following steps: S710 provides a first wafer and a second wafer that need to be bonded.

[0125] S720. For the target wafer in the first wafer and the second wafer, perform at least one mask layer formation based on the photo-acid quencher and a local wafer processing based on the mask layer based on the wafer edge region of the target wafer to form a bonding structure.

[0126] S730, based on a bonding structure, bonds the first wafer and the second wafer.

[0127] In the aforementioned S710, the first wafer and the second wafer can refer to wafers that have undergone other processing steps prior to bonding and have not yet formed bonding trenches. In actual fabrication, wafers are often processed individually based on their type. That is, the first wafer can be processed in a separate batch, and the second wafer can also be processed in a separate batch. Then, a set of wafers processed by both is selected for bonding.

[0128] In the aforementioned S720, the target wafer can refer to the wafer in which the bonding trench is formed. It can be a designation for one of the first wafer and the second wafer, reflecting the processing method of each wafer when forming the bonding trench.

[0129] "Mask layer formation based on photoacid quencher" can refer to the mask layer formation process described in P400 and its related descriptions. Considering the actual requirements when forming bonding trenches, the "substrate surface" involved in this process can be configured as the side of the target wafer where bonding occurs. Since the "mask layer" is generally formed based on positive photoresist, the "photoacid quencher" should be coated on the edge region of the wafer. Therefore, coating the photoacid quencher on the edge region of the wafer (i.e., the aforementioned wafer edge region) ensures that the photoresist in this area is not modified. Combined with positive photoresist, the mask layer can cover the wafer edge region, thus preventing subsequent local wafer processing based on the mask layer from being performed in the wafer edge region.

[0130] Considering that the aforementioned photo-acid quencher is coated on the edge region of the wafer and can be a liquid solution, an edge washing process can be used to apply the photo-acid quencher. That is, a wafer edge washing process can be performed based on the photo-acid quencher to coat the photo-acid quencher in the reserved area (i.e., the edge region of the wafer).

[0131] Considering that bonding structures often manifest as bonding trenches within each wafer, "wafer local processing based on the mask layer" can be configured as a trench etching process on the wafer. That is, wafer local processing includes the wafer etching process. Based on the aforementioned photo-acid quencher, the wafer etching process will not etch the wafer edge region, causing the bonding structure to form outside the wafer edge region. Therefore, the bonding structure will not form in the wafer edge region, thus preventing bubble defects caused by the edge washing process in the wafer edge region.

[0132] In the foregoing description, considering the anomalous formation of bonding structures in the wafer edge region, the wafer edge region can refer to the edge region of the wafer after the edge-washing process. Actual testing has shown that the wafer edge region can be configured as an area extending 1mm to 3mm inward from the outer edge of the target wafer.

[0133] The formation of a photo-acid quencher based on the wafer edge region and the formation of a mask layer based on the photo-acid quencher ensure that the bonding trench is formed outside the wafer edge region. Subsequent bonding steps (i.e., S730) can be performed based on the bonding trench formed outside the wafer edge region to form a bonding structure between the first wafer and the second wafer.

[0134] Furthermore, in the actual fabrication process of the bonding structure, considering the communication requirements between wafers, the bonding structure can further include vias and trenches. The vias can extend from the surface of the target wafer to the internal circuitry of the target wafer (e.g., ...). Figure 6 Medium-depth bonding trenches allow channel bonding trenches on different wafers to bond together, forming conductive channels that connect the internal circuitry of the two wafers, thus enabling communication between them. Surface bonding trenches can be formed only on the surface of the target wafer (e.g., Figure 6 Surface bonding grooves (with moderate to shallow depth) are not used for data communication. They are primarily used to increase the bonding strength between two wafers.

[0135] Based on the aforementioned channel bonding trenches and surface bonding trenches, the bonding structure formation process for the target wafer can be repeated twice to form the aforementioned two types of bonding trenches. To further describe this process, this application also provides an exemplary flowchart of the wafer bonding structure formation process (…). Figure 8 ).

[0136] like Figure 8 As shown, process P800 may include the following steps: S810. Determine the target size of the wafer edge region of the target wafer based on the size of the first wafer and the size of the second wafer.

[0137] S820, performs mask layer formation based on photoacid quencher and wafer local processing based on mask layer to form channel bonding trenches.

[0138] S830, Perform mask layer formation based on photoacid quencher and wafer local processing based on mask layer to form surface bonding trenches.

[0139] S840, Fill the channel bonding groove and surface bonding groove with bonding medium.

[0140] S850 performs an edge-washing process on the wafer edge area.

[0141] S860, Align the first wafer and the second wafer and perform bonding process.

[0142] In the aforementioned S810, the target size of the wafer edge region of the target wafer can be determined based on the foregoing description. For example, the target size of the wafer edge region of the target wafer can be 3 mm.

[0143] In practice, the first and second wafers used for bonding often have the same dimensions; therefore, the delineation of the wafer edge regions is generally the same. Furthermore, considering that the wafer edge regions are curved, direct contact may be undesirable. Before bonding (i.e., after S840 and before S860), one side of the wafer can be trimmed before bonding. In this case, the two wafers will exhibit a certain difference in size. That is, as... Figure 6 As shown, this is the case where the first wafer is smaller than the second wafer.

[0144] In some embodiments, wafer bonding can also be performed based on wafers of different sizes (e.g., edge trimming was performed before performing P800 or wafers of different specifications were used). In this case, the bonding trenches (i.e., the light-transmitting areas in the photomask) that may be covered by the wafer edge region of the smaller wafer may be different from those of the wafer edge region of the larger wafer. Therefore, when performing S810, the photoacid quencher formation region of the larger wafer can be adjusted based on the smaller wafer (i.e., the size of the wafer edge region of the larger wafer can be adjusted).

[0145] Specifically, when the wafer sizes of the first wafer and the second wafer are different, the target size of the edge region of the target wafer can be determined based on the specific object it refers to. If the target wafer refers to the smaller of the first and second wafers (denoted as the first target wafer), the target size of the edge region of the target wafer can be configured as the actual edge size (i.e., the actual edge region for which the edge washing process is performed, specifically 1mm to 3mm as mentioned above). If the target wafer refers to the larger of the first and second wafers (denoted as the second target wafer), the target size of the edge region of the target wafer can be configured as the sum of the difference between the actual edge size and the wafer edge size.

[0146] That is, when executing the aforementioned S810, in response to the fact that the wafer sizes of the first wafer and the second wafer are different and the target wafer is the first target wafer, the target size of the wafer edge region of the target wafer can be configured as the actual edge size. Alternatively, in response to the fact that the wafer sizes of the first wafer and the second wafer are different and the target wafer is the second target wafer, the target size of the wafer edge region of the target wafer can be configured as the sum of the difference between the actual edge size and the wafer edge size, wherein the wafer size of the second target wafer is larger than that of the first target wafer.

[0147] Assumption Figure 6 The two wafers shown had a size difference before bonding; here, we take... Figure 6 Taking the wafer edge region 640 on the right as an example, the determination of the size of the wafer edge region will be explained. Figure 6If the wafer size of the first wafer 610 is smaller than that of the second wafer 620 (it should be noted that the first wafer 610 and the second wafer 620 refer to two wafers that need to be bonded, and the first wafer 610 often refers to the wafer above it, and there is no substantial requirement for its size), then after the two are aligned, a wafer edge size difference d0 is formed in the wafer edge region 640.

[0148] Based on the foregoing description, the first wafer 610 is the first target wafer, and the second wafer 620 is the second target wafer. The size of the wafer edge region of the first wafer 610 can be the actual edge size d1 (for example, it can be 3mm), and the size of the wafer edge region of the second wafer 620 can be the sum of the actual edge size d1 and the difference between the wafer edge size d0 (i.e., d2=d1+d0).

[0149] This ensures that the bonding grooves of the first wafer and the second wafer match each other during bonding, avoiding the situation where a larger wafer forms bonding grooves in the edge area of ​​a smaller wafer due to size differences.

[0150] The aforementioned S820 and S830 can be considered as local processing procedures for two wafers with different etching depths. Their actual fabrication logic is similar, mainly differing in etching depth. For details, please refer to... Figure 6 The bonding structure 630 in the intermediate region, wherein the deeper bonding structure 630 can be formed based on the channel bonding groove, and the shallower bonding structure 630 can be formed based on the surface bonding groove.

[0151] The etching depth of a channel bonding trench within its corresponding wafer can be h1, and the etching depth of a surface bonding trench within its corresponding wafer can be h2. The etching depth h1 of the channel bonding trench is generally determined based on the distance between the bonding surface of the wafer and the metal interconnect layer, so that the channel bonding trench can extend from the surface of the target wafer to the internal circuitry of the target wafer. This allows the bonding structure formed by the interlocking of channel bonding trenches to become a conductive channel connecting the internal circuitry of the two wafers. The etching depth h2 of the surface bonding trench is generally determined based on the thickness of the wafer surface (generally less than this thickness) to avoid affecting other structures within the wafer during its formation.

[0152] After determining the aforementioned etching depth, a mask layer can be formed based on the corresponding photomask and the photo-acid quencher in the wafer edge region. Then, based on the corresponding etching depth, corresponding bonding trenches can be formed to achieve S820 and S830. In actual fabrication, the channel bonding trenches are often fabricated first. After fabricating one bonding trench, the mask layer needs to be removed and regenerated. Methods for removing the mask layer can be found in the aforementioned content and related technologies.

[0153] In the aforementioned S840, the bonding medium is often a metallic medium (such as copper), and its filling can be performed based on a metal-filling process. The surfaces of the bonding media in the two bonding grooves to be bonded need to be mutually compatible so that subsequent processes can heat-bond the bonding media of two different wafers.

[0154] In the aforementioned S850, following the metal-filled bonding medium formation process, if an edge-washing process is not performed, the metal-filling process may cause copper contamination on the wafer surface. Therefore, an edge-washing process can be performed after the aforementioned bonding medium filling is completed. The edge-washing process can be performed adaptively based on the possible residues at the edges. The edge-washing process here is mainly a metal residue edge-washing process. Considering that the aforementioned process involves photoresist etching and subsequent bonding processing, this step may also include a photoresist residue edge-washing process and a pre-bonding edge-washing process.

[0155] Based on the aforementioned settings, when performing the edge-washing process of S850, the bonding structure will not be located within the influence range of the edge-washing process, thereby ensuring the integrity and consistency of the bonding medium morphology within the bonding groove.

[0156] In the aforementioned S860, after processing the two wafers, the two wafers can be aligned and then bonded. For the specific bonding process of the two wafers, please refer to relevant techniques in the art, which will not be elaborated here.

[0157] Therefore, a suitable bonding trench can be formed based on the aforementioned P800, thereby achieving bonding between the first wafer and the second wafer. Furthermore, in addition to the aforementioned semiconductor device manufacturing method, this application also protects semiconductor devices produced based on this manufacturing method. For example, semiconductor devices generated based on the manufacturing methods shown in P700 or P800 are also within the scope of protection of this application. Furthermore, semiconductor devices based on the mask layer formation methods shown in P400 to P500 mentioned above in the semiconductor fabrication process are also within the scope of protection of this application.

[0158] Unexpected technical effects: In summary, the semiconductor device and manufacturing method provided in this application have the following unexpected effects: ① To address the need for flexible adjustment of the mask layer during local wafer processing, this application creatively proposes selective processing of specific areas within the critical process window before photoresist baking using an exogenous photoacid quencher. This method overcomes the limitation of traditional photolithography technology, which relies entirely on the inherent pattern of the mask, enabling proactive and precise secondary definition and local correction of the mask layer pattern without redesigning and fabricating the mask. This significantly reduces the cost and cycle time of R&D iteration and process optimization, providing unprecedented flexibility for rapid prototyping and performance fine-tuning of semiconductor devices.

[0159] ② This application delves into and utilizes the reaction mechanism of chemically amplified photoresist. By precisely eliminating the initial photoacid in the "retained region" before the photoacid catalytic chain reaction (post-baking) occurs, the chemical modification process in this region is fundamentally blocked. This not only ensures the perfect preservation of the photoresist in the retained region during development, but more importantly, because the quenching occurs before the lateral diffusion of the photoacid, it effectively suppresses the blurring phenomenon caused by acid diffusion at the pattern edges, thereby obtaining clearer and more precise pattern boundaries than traditional processes and improving pattern fidelity.

[0160] ③ This application discovers that applying photo-acid quenching technology to wafer bonding (especially hybrid bonding) processes can cleverly solve the long-standing problem of wafer edge bonding defects. By defining the wafer edge region (typically 1-3 mm) as the "reserved region" for photo-acid quenching, the bonding structure (such as bonding grooves) automatically avoids this region during etching. This fundamentally avoids the erosion of the metal dielectric within the bonding structure by subsequent edge washing processes, significantly reduces bubbles and voids at the bonding interface, and improves bonding strength and device reliability, which is particularly significant for advanced packaging and 3D integration technologies.

[0161] ④ By carefully designing the formulation of the photo-acid quencher (such as low molecular weight organic amines, matched solvents, surfactants, and stabilizers), we ensured good compatibility between the reagent and the photoresist, efficient penetration, and process stability. This design allows the quencher to not only quickly reach the action site but also form a stable "protective layer" during the post-baking process, continuously neutralizing any photo-acid that may diffuse there, thus ensuring the robustness and repeatability of the technical solution.

[0162] The embodiments disclosed above are merely illustrative of this application. The embodiments do not exhaustively describe all details, nor do they limit the application to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of this application, thereby enabling those skilled in the art to better understand and utilize this application. This application is limited only by the claims and their full scope and equivalents.

Claims

1. A method for manufacturing a semiconductor device, characterized in that, The manufacturing method includes at least the formation of a mask layer based on a photo-acid quencher and wafer localization based on the mask layer, wherein the formation of the mask layer based on the photo-acid quencher includes: A photoresist layer is formed on the surface of the substrate; The photoresist layer is subjected to an exposure process to modify the portion of the photoresist layer located within the exposure range, thereby generating photoacids. Before post-baking, a photoacid quencher is applied to the reserved area of ​​the photoresist layer to eliminate photoacid in the reserved area; The photoresist layer is subjected to a development process to remove a portion of the photoresist layer that has been photo-modified, thereby forming the mask layer, wherein the mask layer covers the reserved area.

2. The manufacturing method according to claim 1, characterized in that, The photoacid quencher is carried in a liquid solvent. The photoacid quencher is a low-polarity substance that does not repel the polarity of the photoresist layer, thereby allowing it to diffuse into the interior of the photoresist layer and eliminate photoacid.

3. The manufacturing method according to claim 2, characterized in that, The photoacid quencher is configured as an organic base with a molecular weight smaller than the mesh size of the photoresist layer, thereby eliminating photoacid based on the principle of acid-base neutralization; The liquid solvent has a similar polarity to the photoacid quencher.

4. The manufacturing method according to claim 3, characterized in that, The photoacid quencher is configured as a low-polarity organic amine with a molecular weight of less than 300 Da.

5. The manufacturing method according to claim 4, characterized in that, The photoacid quencher is configured as triethylamine and / or diethylamine; The liquid solvent also carries a surfactant and a stabilizer, wherein the surfactant is used to promote the diffusion of the photoacid quencher into the photoresist layer.

6. The manufacturing method according to claim 1, characterized in that, The step of coating the reserved area of ​​the photoresist layer with a photoacid quencher before the post-baking process to eliminate photoacid in the reserved area includes: After the exposure treatment, a photoacid quencher is coated on the retained area to allow the photoacid quencher to penetrate into the retained area and eliminate the initial photoacid in the retained area; The photoresist layer is subjected to a post-baking process, wherein the initial photoacid catalyzes a chain deprotection reaction of the photoresist molecules to allow the photoacid to penetrate the photoresist layer, and the photoacid quencher in the retained region eliminates the initial photoacid and blocks the catalytic reaction.

7. The manufacturing method according to claim 6, characterized in that, After the exposure treatment, the method further includes coating the retained area with a photoacid quencher to allow the photoacid quencher to penetrate the interior of the retained area and eliminate the initial photoacidity within the retained area. A surface cleaning process is performed on the photoresist layer to remove residual photoacid quenchers on the surface of the photoresist layer.

8. The manufacturing method according to claim 1, characterized in that, The semiconductor device includes a first wafer and a second wafer bonded together, and the manufacturing method includes: For the target wafer in the first wafer and the second wafer, the formation of the mask layer and the wafer local processing based on the mask layer are performed on the wafer edge region of the target wafer to form a bonding structure, wherein the surface of the substrate is configured as the side of the target wafer to be bonded, the wafer edge region is configured as the reserved region, the wafer local processing includes a wafer etching process, and the bonding structure is formed outside the wafer edge region; The first wafer and the second wafer are bonded based on the bonding structure.

9. The manufacturing method according to claim 8, characterized in that, The step of coating the reserved area of ​​the photoresist layer with a photoacid quencher before the post-baking process to eliminate photoacid in the reserved area includes: Prior to the post-baking process, a wafer washing process is performed based on the photo-acid quencher to coat the retained area with the photo-acid quencher.

10. A semiconductor device, characterized in that, The semiconductor device includes a first wafer and a second wafer, and a pair of bonding structures are disposed between the first wafer and the second wafer. The bonding structure forms a reserved region of the mask layer based on the manufacturing method according to any one of claims 1 to 9 and is configured on the wafer edge region of the wafer, so that the bonding structure avoids the wafer edge regions of the first wafer and the second wafer during formation; The first wafer and the second wafer are bonded to each other through the bonding structure.

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