Method for manufacturing a semiconductor and semiconductor unit

Abstract

The application relates to the field of semiconductor manufacturing, in particular to a semiconductor manufacturing method and a semiconductor unit, which comprises the following steps: forming exposure regions: according to the semiconductor unit to be formed, a plurality of exposure regions are formed on a wafer by using a photolithography technology; and forming alignment marks: in each exposure region, an alignment mark is formed by a photolithography step or an etching step. The semiconductor manufacturing method has the advantages that the alignment mark is arranged in the exposure region, the identification of the alignment mark is improved, the misjudgment of the photolithography machine on the alignment mark between adjacent exposure regions is effectively avoided, the error identification of the alignment mark is prevented, and therefore the manufacturing quality and performance of the chip are improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing, and more specifically, to a method for preparing a semiconductor and a semiconductor unit. Background Technology

[0002] In semiconductor manufacturing, layout is a crucial technical step, and the precise positioning of alignment marks is essential to ensuring manufacturing accuracy. Specifically, semiconductor cells (DIEs) are typically arranged in a matrix on a wafer, forming several exposure areas (SHOTs). To achieve precise alignment between these exposure areas, alignment marks need to be placed between them.

[0003] However, a significant problem exists in existing technologies: due to the limited spacing between exposure areas, when alignment marks are placed too close together, the lithography machine cannot accurately identify the corresponding exposure area, leading to misjudgment. This misjudgment not only reduces production efficiency but can also seriously affect the manufacturing quality and performance of the chip. Summary of the Invention

[0004] The purpose of this invention is to provide a method for fabricating a semiconductor that can improve the recognition of alignment marks.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a semiconductor, comprising:

[0006] Forming exposure areas: Based on the semiconductor units to be formed, several exposure areas are formed on the wafer using photolithography.

[0007] Forming alignment marks: Alignment marks are formed in each of the exposure areas by a photolithography or etching step.

[0008] Furthermore, the alignment marks are arranged in inactive regions of the semiconductor cell or in filling regions used for process compensation.

[0009] Furthermore, the exposure area is defined with a center and an edge, and the alignment mark is located near the center.

[0010] Furthermore, the alignment marks are formed using a low dielectric constant material or a high resistivity material.

[0011] Furthermore, prior to "forming alignment marks", the process also includes: applying a thermal stress buffer layer using a deposition technique;

[0012] The alignment marks are formed on the thermal stress buffer layer.

[0013] Furthermore, the material used in the thermal stress buffer layer is one of silicate glass, polyimide, polystyrene, silicon nitride, and aluminum oxide.

[0014] Furthermore, the semiconductor fabrication method further includes: forming a metal shielding layer using metal deposition technology, wherein the metal shielding layer covers the alignment mark and extends to the inactive region of the semiconductor cell.

[0015] The present invention also provides a semiconductor unit, which is manufactured using the semiconductor preparation method described above.

[0016] The beneficial effects of this invention are as follows: the semiconductor fabrication method of this application, by setting alignment marks within the exposure area, helps to improve the identification of alignment marks, effectively avoids misjudgment of alignment marks between adjacent exposure areas by the lithography machine, prevents incorrect identification of alignment marks, and thus helps to improve the manufacturing quality and performance of the chip.

[0017] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating a semiconductor fabrication method according to an embodiment of the present invention. Detailed Implementation

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

[0020] In the description of this invention, 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 the invention and for 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 the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0023] Please see Figure 1 The semiconductor fabrication method shown in one embodiment of the present invention includes:

[0024] Forming exposure areas: Based on the semiconductor cells (DIEs) to be formed, several exposure areas (SHOTs) are formed on the wafer using photolithography.

[0025] Forming alignment marks: In each exposure area, alignment marks are formed by photolithography or etching. In this embodiment, the exposure area is defined with a center and an edge, and the alignment marks are close to the center.

[0026] The semiconductor fabrication method improves the recognition of alignment marks by setting alignment marks within the exposure area, effectively avoiding misjudgment of alignment marks between adjacent exposure areas by the lithography machine, preventing incorrect recognition of alignment marks, and thus helping to improve the manufacturing quality and performance of the chip.

[0027] Semiconductor cells have active and inactive regions. Active regions are those in a semiconductor device that perform the main functions or electrical activities. During semiconductor manufacturing, these regions are typically defined and formed through specific process steps (such as photolithography, etching, and doping). Active regions usually contain critical structures of the semiconductor device, such as the source, drain, and gate of a transistor, or the PN junction of a diode. These structures play crucial roles in conducting electricity, controlling current, or controlling voltage during device operation. Inactive regions, on the other hand, are those in a semiconductor device that do not directly participate in the main functions or electrical activities. These regions are typically located around or inside the active regions, providing auxiliary functions such as structural support, isolation, or protection. In this embodiment, alignment marks are arranged in the inactive regions of the semiconductor cell. This arrangement helps ensure that they do not interfere with the main functional regions of the semiconductor cell, thereby avoiding negative impacts on the performance of the semiconductor device.

[0028] In some embodiments, inactive regions may contain process compensation structures (such as fill regions) to balance stress on the wafer, reduce thermal effects, or optimize electrical performance. In some embodiments, alignment marks may also be arranged in or used in the fill regions for process compensation.

[0029] In this embodiment, the alignment mark is formed of a low-k dielectric material (e.g., silicon-based polymer material, aerogel-based material) or a high-resistivity material (e.g., alumina, silicon nitride). By using the above materials to form the alignment mark, the interaction between the alignment mark and the semiconductor cell can be reduced, thereby reducing the impact on the performance of the semiconductor cell.

[0030] Before "forming alignment marks," a thermal stress buffer layer is applied using deposition techniques (such as spin coating, sputtering, chemical vapor deposition, etc.). Alignment marks are formed on the thermal stress buffer layer. This buffer layer absorbs and disperses thermal stress, thereby reducing damage to the semiconductor cell. Simultaneously, the thermal stress buffer layer improves the reliability and stability of the semiconductor device and extends its lifespan. This thermal stress buffer layer is made of one of the following: silicate glass, polyimide (PI), polystyrene (PS), silicon nitride (SiN), or alumina (Al2O3). In an alternative embodiment, to avoid insufficient adhesion between the stress buffer layer and the wafer surface, an intermediate layer, such as a titanium (Ti) or chromium (Cr) metal layer, can be introduced between the wafer surface and the stress buffer layer to improve the adhesion between them.

[0031] In one embodiment, to prevent alignment marks from interfering with functional circuitry, the semiconductor fabrication method further includes: forming a metal shielding layer using metal deposition techniques (such as sputtering, electroplating, chemical vapor deposition (CVD), or atomic layer deposition (ALD), etc.). The metal shielding layer covers the alignment marks and extends to the inactive areas of the semiconductor cell. The metal material used for the metal shielding layer includes copper (Cu), aluminum (Al), gold (Au), silver (Ag), and alloy materials, depending on the specific circumstances.

[0032] It should be noted that in actual manufacturing, the complete semiconductor fabrication method includes not only the steps mentioned above, but also wafer cleaning, oxidation, doping, deposition, etching, ion implantation, metallization, and packaging. These steps can be carried out using conventional methods in existing technologies, so they will not be described in detail here.

[0033] This embodiment also provides a semiconductor unit, which is manufactured using the above-described preparation method.

[0034] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0035] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for preparing a semiconductor, characterized in that, include: Forming exposure areas: Based on the semiconductor units to be formed, several exposure areas are formed on the wafer using photolithography. Forming alignment marks: Alignment marks are formed in each of the exposure areas by a photolithography or etching step.

2. The method for preparing a semiconductor as described in claim 1, characterized in that, The alignment marks are arranged in the inactive region of the semiconductor cell or in the fill region used for process compensation.

3. The method for preparing a semiconductor as described in claim 2, characterized in that, The exposure area is defined by a center and an edge, and the alignment mark is located near the center.

4. The method for preparing a semiconductor as described in claim 2, characterized in that, The alignment marks are formed using a low dielectric constant material or a high resistivity material.

5. The method for preparing a semiconductor as described in claim 2, characterized in that, The process before "forming alignment marks" also includes: applying a thermal stress buffer layer using a deposition technique; The alignment marks are formed on the thermal stress buffer layer.

6. The method for preparing a semiconductor as described in claim 5, characterized in that, The thermal stress buffer layer is made of one of the following materials: silicate glass, polyimide, polystyrene, silicon nitride, and aluminum oxide.

7. The method for preparing a semiconductor as described in claim 2, characterized in that, The semiconductor fabrication method further includes: forming a metal shielding layer using metal deposition technology, wherein the metal shielding layer covers the alignment mark and extends to the inactive region of the semiconductor cell.

8. A semiconductor unit, characterized in that, The semiconductor unit is manufactured using the semiconductor preparation method as described in any one of claims 1 to 7.

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