A method of improving the morphology of corrosion

Abstract

The application discloses a method for improving the morphology of corrosion, which comprises the following steps: S1, first, checking the equipment state before corrosion, ensuring that there is no abnormality, then adjusting the process, adopting a mechanical chemical corrosion process to perform chemical thinning on a semiconductor silicon wafer, preparing auxiliary materials required in the process, and adjusting process parameters such as the rotating speed of a mechanical arm of a corrosion machine, the nitrogen path in an acid tank, the temperature of a corrosion ice machine and the nitrogen flow; S2, then, adjusting the concentration and temperature of a liquid medicine to determine the removal rate of corrosion, thereby affecting the corrosion morphology of the final corrosion, and ensuring that the position setting of the moving nitrogen pipe in the acid tank is consistent with the actual moving position. The application adjusts the concentration of mixed acid, the moving position of the nitrogen pipe and the nitrogen flow and the like to improve the uniformity of the surface corrosion of the silicon wafer in the corrosion process, achieves the purpose of improving the morphology of the silicon wafer, and better improves the process capacity and reduces the product parameter failure rate.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, specifically to a method for improving morphology through etching. Background Technology

[0002] In the global semiconductor materials field, the advent of the 5G era has led to a significant increase in silicon content in downstream electronic devices, driving rapid growth in semiconductor demand. This has directly spurred wafer manufacturers to expand their production capacity. Currently, 200mm wafer fabs remain the primary source of profit globally. The increasing demand for wafers and the expanding scale of industrial production necessitate a high-speed, continuous, and high-precision production model, placing higher demands on silicon substrates. Currently, acid-etched silicon wafers are more difficult to control in terms of etching efficiency and geometric parameters compared to alkaline-etched wafers. However, acid-etched silicon wafers offer several advantages: a smoother surface, lower roughness, lower surface metal content, and higher production efficiency. These advantages make acid-etched silicon wafers increasingly popular. This silicon wafer etching process improves wafer morphology, thereby further controlling geometric parameters and enhancing market competitiveness. Summary of the Invention

[0003] The purpose of this invention is to provide a method for improving the morphology through etching, in order to address the challenges posed by the increasing demand for wafers and the expanding scale of industrial production, which require high-speed, continuous, and high-precision production, thus placing higher demands on silicon substrates. Currently, compared to alkaline etching, acid etching of silicon wafers presents greater challenges in controlling the etching efficiency and geometric parameters.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for improving morphology through corrosion, the method comprising the following steps:

[0005] S1. First, check the equipment status before etching to ensure there are no abnormalities before adjusting the process. Use mechanical-chemical etching to chemically thin the semiconductor silicon wafer. Prepare the auxiliary materials required for the process. The auxiliary materials required for the process are hydrofluoric acid, nitric acid and acetic acid, and the ratio of the auxiliary materials is 1.0:3.4:1.6. Adjust the process parameters such as the speed of the etching machine's robotic arm, the nitrogen path in the acid tank, the temperature of the etching machine and the nitrogen flow rate.

[0006] S2. Then, the corrosion removal rate is determined by adjusting the concentration and temperature of the chemical solution, which in turn affects the final corrosion morphology. The nitrogen flow rate is calibrated to ensure that it is within the set value. The position of the moving nitrogen pipe in the acid tank is ensured to match the actual position, reducing abnormal corrosion morphology caused by the position of the nitrogen pipe and preventing abnormal experimental results due to abnormal nitrogen flow during corrosion. The mixed acid concentration meter and cooling water flow rate are calibrated to ensure that the product removal rate and corrosion temperature are stable during processing. After the process adjustment is completed, the equipment is checked again to ensure that there are no abnormalities before processing begins.

[0007] S3. Finally, the silicon wafer is poured into the roller by the wafer deflector and fixed with nuts. The roller is then fixed to the robotic arm with nuts. The robotic arm drives the roller into the acid tank. The motor drives the roller to rotate the silicon wafer in the acid tank for etching. After etching, the robotic arm drives the roller into the water washing tank for rinsing.

[0008] Preferably, the mechanical arm of the corrosion machine is set to a rotation speed of 50, the temperature of the corrosion ice machine is set to 14℃, and the nitrogen flow rate is guaranteed to be above 220L / min.

[0009] Compared with the prior art, the beneficial effects of the present invention are: the present invention improves the corrosion uniformity of silicon wafer surface during the etching process by adjusting the mixed acid concentration, the moving position of the nitrogen pipe and the nitrogen flow rate, thereby improving the silicon wafer morphology, thereby better improving the process capability, reducing the product parameter defect rate and enhancing market competitiveness. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the silicon wafer etching principle of the present invention;

[0011] Figure 2 This is a flowchart of the corrosion process of the present invention;

[0012] Figure 3 This is a schematic diagram showing the movement position of the nitrogen pipe inside the acid tank according to the present invention;

[0013] Figure 4 This is a comparison of corrosion morphology before and after the improvement of the present invention. Detailed Implementation

[0014] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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. Example 1:

[0015] See Figure 1-4The improvement method in this embodiment includes the following steps:

[0016] A method for improving morphology through corrosion, characterized by the following steps:

[0017] S1. First, check the equipment status before etching to ensure there are no abnormalities before adjusting the process. Use mechanical-chemical etching to chemically thin the semiconductor silicon wafer. Prepare the auxiliary materials required for the process. The auxiliary materials required for the process are hydrofluoric acid, nitric acid, and acetic acid, and the ratio of hydrofluoric acid, nitric acid, and acetic acid is 1.0 : 3.4 : 1.6. After confirming the above preparation conditions, adjust the path of the moving nitrogen pipe in the acid tank from the original F: -45, R: 95, S: 100 to the current F: -75, R: 105, S: 10. Then, control the unevenness of the morphology according to the nitrogen time and adjust the process parameters of the etching machine robotic arm speed, nitrogen path in the acid tank, etching machine temperature, and nitrogen flow rate.

[0018] S2. Then, the corrosion removal rate is determined by adjusting the concentration and temperature of the chemical solution, which in turn affects the final corrosion morphology. Ensure that the position of the moving nitrogen pipe in the acid tank matches the actual moving position to reduce abnormal corrosion morphology caused by the position of the nitrogen pipe. Calibrate the nitrogen flow rate to ensure that the nitrogen flow rate is within the set value to prevent abnormal experimental results caused by abnormal nitrogen flow rate during the corrosion process. Calibrate the mixed acid concentration meter and cooling water flow rate to ensure that the product removal rate and corrosion temperature are stable during the processing. After the process adjustment is completed, the equipment is checked again to ensure that there are no abnormalities before processing begins.

[0019] S3. Finally, the silicon wafer is poured into the roller by the wafer deflector and fixed with nuts. The roller is then fixed to the robotic arm with nuts. The robotic arm drives the roller into the acid tank. The motor drives the roller to rotate the silicon wafer in the acid tank for etching. After etching, the robotic arm drives the roller into the water washing tank for rinsing.

[0020] In this embodiment, the rotation speed of the corrosion machine's robotic arm is set to 50, the temperature of the corrosion ice machine is set to 14°C, and the nitrogen flow rate is guaranteed to be above 220L / min. F represents the forward path, R represents the backward path, and S represents the nitrogen flow rate per minute. Example 2:

[0021] The distinguishing feature from Embodiment 1 is as follows:

[0022] The improvement method in this embodiment includes the following steps:

[0023] A method for improving morphology through corrosion, characterized by the following steps:

[0024] S1. First, check the equipment status before etching to ensure there are no abnormalities before adjusting the process. Use mechanical chemical etching to chemically thin the semiconductor silicon wafer. Prepare the auxiliary materials required for the process. The auxiliary materials required for the process are hydrofluoric acid, nitric acid and acetic acid, and the ratio of the auxiliary materials is 2.0: 5.4: 3.6. Adjust the process parameters by adjusting the speed of the etching machine's robotic arm, the nitrogen path in the acid tank, the temperature of the etching machine and the nitrogen flow rate.

[0025] S2. Then, the corrosion removal rate is determined by adjusting the concentration and temperature of the chemical solution, which in turn affects the final corrosion morphology. By calibrating the nitrogen flow rate, the nitrogen flow rate is ensured to be within the set value. The position of the moving nitrogen pipe in the acid tank is ensured to match the actual position, reducing abnormal corrosion morphology caused by the position of the nitrogen pipe and preventing abnormal experimental results due to abnormal nitrogen flow during the corrosion process. The mixed acid concentration meter and cooling water flow rate are calibrated to ensure that the product removal rate and corrosion temperature are stable during the processing. After the process adjustment is completed, the equipment is checked again to ensure that there are no abnormalities before processing begins.

[0026] S3. Finally, the silicon wafer is poured into the roller by the wafer deflector and fixed with nuts. The roller is then fixed to the robotic arm with nuts. The robotic arm drives the roller into the acid tank. The motor drives the roller to rotate the silicon wafer in the acid tank for etching. After etching, the robotic arm drives the roller into the water washing tank for rinsing.

[0027] In this embodiment, the rotation speed of the corrosion machine's robotic arm is set to 30, the temperature of the corrosion ice machine is set to 10°C, and the nitrogen flow rate is ensured to be above 110L / min.

[0028] In summary, the experimental results of Embodiment 1 of this invention show that, compared with the process experimental results of Embodiment 2, this invention, by adjusting the mixed acid concentration, the moving position of the nitrogen pipe, and the nitrogen flow rate, more effectively improves the corrosion uniformity of the silicon wafer surface during the etching process, thereby achieving a better improvement in the silicon wafer morphology, thus better enhancing process capability and reducing product parameter defect rate.

[0029] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, technology, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, technology, article, or apparatus.

[0030] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for improving morphology through corrosion, characterized in that: The improvement method includes the following steps: S1. First, check the equipment status before etching to ensure there are no abnormalities before adjusting the process. Use mechanical chemical etching to chemically thin the semiconductor silicon wafer. Prepare the auxiliary materials required for the process. The auxiliary materials required for the process are hydrofluoric acid, nitric acid and acetic acid, and the ratio of the auxiliary materials is 1.0:3.4:1.

6. Adjust the process parameters such as the speed of the etching machine's robotic arm, the nitrogen path in the acid tank, the temperature of the etching machine and the nitrogen flow rate. S2. Then, the corrosion removal rate is determined by adjusting the concentration and temperature of the chemical solution, which in turn affects the final corrosion morphology. The nitrogen flow rate is calibrated to ensure that it is within the set value. The path of the moving nitrogen pipe in the acid tank is adjusted to ensure that the position of the moving nitrogen pipe in the acid tank matches the actual position, reducing abnormal corrosion morphology caused by the position of the nitrogen pipe and preventing abnormal experimental results caused by abnormal nitrogen flow during the corrosion process. The mixed acid concentration meter and cooling water flow rate are calibrated to ensure that the product removal rate and corrosion temperature are stable during the processing. After the process adjustment is completed, the equipment is checked again to ensure that there are no abnormalities before processing begins. S3. Finally, the silicon wafer is poured into the roller by the wafer deflector and fixed with nuts. The roller is then fixed to the robotic arm with nuts. The robotic arm drives the roller into the acid tank. The motor drives the roller to rotate the silicon wafer in the acid tank for etching. After etching, the robotic arm drives the roller into the water washing tank for rinsing.

2. The method for improving morphology through corrosion according to claim 1, characterized in that: The temperature of the corrosion ice machine was set at 14℃, and the nitrogen flow rate was guaranteed to be above 220L / min.

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