A deep etch profile limiting alignment method for a photolithography machine

Abstract

The application discloses a deep etching contour limiting and shrinking alignment method for a photoetching machine, which can be used on a photoetching machine in the field of micro-nano processing. The method comprises the following steps: firstly, a deep etching peripheral contour is added on a to-be-exposed substrate before the alignment mark pattern of a first photo mask; the peripheral contour is used to limit and shrink the alignment range, so that the manual or automatic coarse adjustment of the alignment process is accelerated, and the alignment mark pattern on the photo mask is in the deep etching peripheral contour on the to-be-exposed substrate; and then, the automatic fine adjustment alignment process is performed through an automatic image recognition technology. The method can avoid the damage of the alignment mark pattern after a plurality of processes by using the deep etching contour, can assist in clear identification and accelerate the alignment process, and can effectively improve the precision and speed of the photoetching machine alignment, and then improve the precision and efficiency of micro-nano processing.

Description

[0001] This invention relates to the field of photolithography alignment technology in micro-nano fabrication, and more specifically, to a deep etching contour limiting alignment method for photolithography machines. Background Technology

[0002] In semiconductor manufacturing processes, lithography machines are the most technically challenging and expensive key equipment in integrated circuit manufacturing. Their development plays a leading role in the development of the integrated circuit and information industries. Photomask and silicon wafer alignment is one of the three core technologies of lithography machines, especially when multiple exposure processes are required for component patterns; precise alignment between components and photomasks is a necessary process. For small-batch integrated circuit manufacturing, inexpensive manual and semi-automatic lithography machines are used. However, manual alignment is a major time-consuming factor in manual and semi-automatic lithography processes. Therefore, this invention proposes an effective deep-etch contour-limited alignment method for lithography machines, utilizing deep-etch contours to assist in clear identification and accelerate the alignment process. Summary of the Invention

[0003] This invention provides a deep etching contour limiting alignment method for lithography machines to facilitate the alignment of components and photomasks during the exposure process.

[0004] The technical solution adopted in this invention is as follows:

[0005] A deep etching contour limiting alignment method for a photolithography machine, the method mainly includes the following steps:

[0006] Step 1: Before the alignment mark pattern of the first photomask, a deep etched outer contour is added to the substrate to be exposed. After that, the alignment mark pattern of each photomask is designed to be located within the outer contour range.

[0007] Step 2: Before the substrate to be exposed undergoes a second or subsequent exposure process, use the outer contour marking to help speed up the manual or automatic coarse adjustment alignment process;

[0008] Step 3: Once it is confirmed that the alignment mark pattern on the photomask is within the outer contour mark of the substrate to be exposed, automatic image recognition technology can be used to automatically fine-tune the alignment process by adjusting the relative position of the outer contour and the alignment pattern to achieve precise alignment.

[0009] Preferably, the addition of a deep-etched outer contour on the substrate to be exposed is achieved by first adding another exposure process and using a high aspect ratio deep etching process to obtain the outer contour pattern on the substrate to be exposed.

[0010] Preferably, the outer contour design of the deep etching can be a square frame, a rectangular frame, a circular frame, or other regular and irregular graphic frames.

[0011] Preferably, the alignment mark pattern can be a square, rectangle, cross, rhombus, star, or other regular polygons, irregular polygons, regular arcs, and irregular arcs.

[0012] Preferably, the size of the alignment mark pattern design should be smaller than the size of the deep-etched outer contour design, so that the outer contour can completely surround the alignment mark pattern and the pattern is placed within the deep-etched outer contour without overlapping.

[0013] Preferably, the manual or automatic coarse adjustment alignment process involves manually or automatically aligning the photomask alignment mark pattern within the outer contour of the substrate to be exposed.

[0014] Preferably, the automatic image recognition technology performs an automatic fine-tuning alignment process, that is, through various intelligent image recognition technologies, it first automatically captures the set outer contour range, and then narrows it down to recognizing only the alignment mark patterns of the photomask and the substrate to be exposed within the outer contour range.

[0015] Preferably, the automatic fine-tuning alignment process involves automatically adjusting the relative position of the stage for placing the substrate to be exposed by using the alignment mark patterns on the photomask and the substrate to be exposed, which are captured in real time by automatic image recognition technology, so as to achieve complete overlap of the alignment mark patterns on the photomask and the substrate to be exposed, thereby achieving the final alignment.

[0016] In summary, this invention provides a deep-etched contour-limiting alignment method for photolithography machines. By adding a deep-etched outer contour to the substrate to be exposed before the alignment mark pattern of the first photomask, the alignment range is limited by the outer contour, making coarse and automatic fine adjustments more convenient and accurate. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall steps in Embodiment 1 of the present invention;

[0018] Figure 2 This is a schematic diagram of coarse alignment in Embodiment 2 of the present invention;

[0019] Figure 3 This is a schematic diagram of coarse alignment in Embodiment 3 of the present invention;

[0020] Reference numerals: a) Pre-etched outer contour and first alignment mark pattern; b) Second and subsequent alignment mark patterns; c) Coarse alignment; d) Fine alignment; 1. Pre-etched outer contour; 2. First alignment mark pattern. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are merely one embodiment of the present invention, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0022] Example 1

[0023] This embodiment takes a deep etching contour limiting alignment method for a lithography machine, in which the alignment mark is cross-shaped and the outer contour of the deep etching is square, as an example, and includes the following steps:

[0024] Step 1: Before the cross-shaped alignment mark pattern of the first photomask, add a deeply etched square outer contour on the substrate to be exposed.

[0025] Step 2: Before the substrate to be exposed undergoes a second or subsequent exposure process, use the square outer contour to help accelerate manual or automatic coarse adjustments so that the cross-shaped alignment mark pattern for the second or subsequent exposures moves within the square outer contour area.

[0026] Step 3: Once it is confirmed that the cross-shaped alignment mark pattern on the photomask is within the square outer contour mark of the substrate to be exposed, the CCD image, algorithm and program can be used to automatically fine adjust the alignment process by the relative position of the square outer contour and the cross-shaped alignment mark, and finally achieve precise alignment.

[0027] Example 2

[0028] This embodiment takes a deep etching contour limiting alignment method for a lithography machine, in which the alignment mark is a pentagram and the outer contour of the deep etching is designed as a circular contour, as an example, and includes the following steps:

[0029] Step 1: Before the five-pointed star alignment mark pattern of the first photomask, add a deeply etched circular outline on the substrate to be exposed.

[0030] Step 2: Before the substrate to be exposed undergoes a second or subsequent exposure process, use the circular outer contour to help accelerate manual or automatic coarse adjustments so that the pentagonal alignment mark pattern for the second or subsequent exposures moves within the circular outer contour area.

[0031] Step 3: Once it is confirmed that the pentagram alignment mark pattern on the photomask is within the circular outer contour mark of the substrate to be exposed, the CCD image, algorithm and program can be used to automatically fine adjust the alignment process by the relative position of the circular outer contour and the pentagram alignment mark, and finally achieve precise alignment.

[0032] Example 3

[0033] This embodiment takes a deep etching contour limiting alignment method for a lithography machine, in which the alignment mark is a pentagon and the outer contour of the deep etching is designed as a trapezoidal contour, as an example, and includes the following steps:

[0034] Step 1: Before the pentagonal alignment mark pattern of the first photomask, add a deeply etched trapezoidal outer contour on the substrate to be exposed;

[0035] Step 2: Before the substrate to be exposed undergoes a second or subsequent exposure process, use the trapezoidal outer contour to help accelerate manual or automatic coarse adjustments so that the pentagonal alignment mark pattern for the second or subsequent exposures moves within the trapezoidal outer contour area.

[0036] Step 3: Once it is confirmed that the pentagonal alignment mark pattern on the photomask is within the trapezoidal outer contour mark of the substrate to be exposed, the CCD image, algorithm and program can be used to automatically fine adjust the alignment process by the relative position of the trapezoidal outer contour and the pentagonal alignment pattern, and finally achieve precise alignment.

Claims

1. A method for deep etching contour compression alignment in a photolithography machine, characterized in that, By adding a deeply etched outer contour to the substrate to be exposed before the alignment mark pattern of the first photomask, the alignment range is narrowed by the outer contour, making it easier and more accurate to perform coarse and automatic fine alignment. The addition of the deeply etched outer contour to the substrate to be exposed is achieved by adding another exposure process beforehand and using a high aspect ratio deep etching process to obtain the outer contour pattern on the substrate to be exposed. The size of the alignment mark pattern is designed to be smaller than the size of the deeply etched outer contour, so that the outer contour can completely surround the alignment mark pattern and place the pattern within the deeply etched outer contour without overlap.

2. The deep etching contour limiting alignment method for a photolithography machine according to claim 1, characterized in that, The process includes the following steps: Step 1: Before the alignment mark pattern of the first photomask, a deep-etched outer contour is added to the substrate to be exposed. This is achieved by adding another exposure process beforehand and using a high aspect ratio deep etching process to obtain the outer contour pattern on the substrate to be exposed. Subsequently, the alignment mark pattern of each photomask is designed to be located within the outer contour range. The size of the alignment mark pattern is smaller than the size of the deep-etched outer contour, so that the outer contour can completely surround the alignment mark pattern and place it within the deep-etched outer contour without overlap. Step 2: Before the second or subsequent exposure process on the substrate to be exposed, the outer contour marks are used to help accelerate the manual or automatic coarse adjustment alignment process. Step 3: Once it is confirmed that the alignment mark pattern on the photomask is within the outer contour marks on the substrate to be exposed, automatic image recognition technology can be used to automatically adjust the alignment process by the relative position of the outer contour and the alignment pattern to achieve precise alignment.

3. The deep etching contour limiting alignment method for a photolithography machine according to claim 2, characterized in that: The outer contour design of the deep etching can be a square frame, a rectangular frame, a circular frame, or other regular and irregular graphic frames.

4. The deep etching contour limiting alignment method for a photolithography machine according to claim 2, characterized in that: The alignment mark pattern can be a square, rectangle, cross, rhombus, star, or other regular polygons, irregular polygons, regular arcs, and irregular arcs.

5. The deep etching contour limiting alignment method for a photolithography machine according to claim 2, characterized in that: The manual or automatic coarse adjustment alignment process involves manually or automatically aligning the photomask alignment mark pattern within the outer contour of the substrate to be exposed.

6. The method for deep etching contour limiting alignment for a photolithography machine according to claim 2, characterized in that: The automatic image recognition technology performs an automatic fine-tuning alignment process, which involves using various intelligent image recognition technologies to first automatically capture the set outer contour range, and then narrowing it down to recognizing only the alignment mark patterns of the photomask and the substrate to be exposed within the outer contour range.

7. The deep etching contour limiting alignment method for a photolithography machine according to claim 2, characterized in that: The automatic fine-tuning alignment process involves using automatic image recognition technology to capture alignment mark patterns on the photomask and the substrate to be exposed in real time, and automatically adjusting the relative position of the stage on which the substrate to be exposed is placed, so as to achieve complete overlap of the alignment mark patterns on the photomask and the substrate to be exposed, thereby achieving the final alignment.

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