Novel quartz crucible
By designing pot walls of specific shapes and angles on the quartz crucible pot walls, increasing the friction between silicon molten soup and quartz crucible, the problem of low mechanical strength of silicon wafers caused by traditional CZ method is solved, and silicon wafer machinery is realized Increase in strength and decrease in debris rate.
Patent Information
- Application Number
- CN202323376413.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-12
- Publication Date
- 2025-02-21
- Estimated Expiration
- 2033-12-12
AI Technical Summary
The traditional CZ method long crystal quartz crucible leads to low mechanical strength of silicon wafers, prone to fragmentation, and a high total fragmentation rate, affecting product quality and economic benefits.
Design a new type of quartz crucible. The pot wall is small at the top and large at the bottom. The angle between the section of the pot wall and the vertical direction is 15°, which increases the friction between the silicon melting soup and the inclined wall in the quartz crucible, thereby improving melting and dissolution. Rate and trace oxygen Oi concentration increase the oxygen content in the seed rod.
By increasing the trace oxygen Oi concentration in the silicon melting soup, the oxygen content in the seed rod is increased, the mechanical strength of the silicon wafer is significantly improved, the fragmentation rate is reduced, and the product quality and economic benefits are improved.
Smart Images
Figure CN222512998U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of single crystal silicon manufacturing equipment, in particular to a novel quartz crucible. Background Art
[0002] The CZ method, or the direct-pull single crystal manufacturing method, is to place the raw polycrystalline silicon block into a quartz crucible, heat and melt it in a single crystal furnace, and then immerse a rod-shaped crystal seed (called a seed crystal) with a diameter of only 10 mm into the melt.
[0003] In the traditional CZ method crystal growth quartz crucible, the crucible wall has a vertical angle of 0 degrees, the heat convection and friction between the silicon melt and the quartz crucible (SiO2) are low, and the final oxygen content in the crystal rod is about 15-30ppma. Among them, the part below 20ppma has low mechanical strength of the processed wafer, which is easy to cause silicon wafer processing and IC tape-out process fragmentation, with a total fragmentation rate of about 2%. Therefore, we need to propose a new type of quartz crucible. Utility Model Content
[0004] The utility model aims to provide a novel quartz crucible, by integrally forming a round sleeve-shaped pot wall which is small at the top and large at the bottom on the pot bottom, and the angle between the pot wall cross section and the vertical direction is 15°, so that the silicon melt rubs against the inclined wall inside the quartz crucible, thereby increasing the melting rate of the quartz crucible, thereby increasing the concentration of trace oxygen Oi in the silicon melt, and finally increasing the oxygen content in the seed crystal rod, thereby increasing the mechanical strength of the silicon wafer, significantly improving the product quality, and achieving remarkable economic benefits, so as to solve the problems raised in the above-mentioned background technology.
[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:
[0006] A novel quartz crucible comprises a quartz crucible pot body for CZ method crystal growth and silicon melt for crystal growth located in the pot body, wherein a seed crystal rod is placed in the pot body;
[0007] The pot body comprises a pot bottom and a pot wall on the pot bottom, wherein the pot wall is arranged around the pot bottom and is formed integrally with the pot bottom, and the pot wall is arranged in a circular sleeve shape with a small top and a large bottom.
[0008] Preferably, the angle between the cross section of the pot wall and the vertical direction is 15°.
[0009] Preferably, the lower end of the seed rod extends below the liquid surface of the silicon melt.
[0010] Compared with the prior art, the beneficial effects of the utility model are:
[0011] The utility model forms a round sleeve-shaped pot wall which is small at the top and large at the bottom on the pot bottom, and the angle between the cross section of the pot wall and the vertical direction is 15 degrees, so that the silicon melt rubs against the inclined wall inside the quartz crucible, thereby increasing the melting rate of the quartz crucible, thereby increasing the concentration of trace oxygen Oi in the silicon melt, and finally increasing the oxygen content in the seed crystal rod, thereby increasing the mechanical strength of the silicon wafer, significantly improving the product quality, and achieving remarkable economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 It is a schematic diagram of the structure of the utility model;
[0013] Figure 2 It is a cross-sectional view of the utility model;
[0014] Figure 3 This is a schematic diagram of the new quartz crucible and crystal growth;
[0015] Figure 4 Schematic diagram of conventional quartz crucible and crystal growth.
[0016] In the figure: 1. pot bottom; 2. pot wall; 3. silicon melt; 4. seed rod. DETAILED DESCRIPTION
[0017] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0018] See also Figure 1-2 , the utility model provides a technical solution:
[0019] A novel quartz crucible includes a quartz crucible pot body for CZ method crystal growth and a silicon melt 3 for crystal growth located in the pot body, and a seed rod 4 is placed in the pot body; the pot body includes a pot bottom 1 and a pot wall 2 on the pot bottom 1, the pot wall 2 is arranged around the pot bottom 1 and is integrally formed with the pot bottom 1, and the pot wall 2 is arranged in a round sleeve shape with a small upper part and a large lower part. The angle between the cross section of the pot wall 2 and the vertical direction is 15°. The lower end of the seed rod 4 extends below the liquid surface of the silicon melt 3.
[0020] like Figure 1-3 As shown, Figure 3 This is a schematic diagram of the new quartz crucible and crystal growth. Figure 3 The middle curved arrow indicates the convection direction of the silicon melt 3, and the seed crystal rod 4 is a heavily doped crystal rod with a resistivity lower than 1Ω.cm;
[0021] At this time, the molten metal rubs against the inclined wall inside the quartz crucible, increasing the melting rate of the quartz crucible, increasing the concentration of trace oxygen Oi in the silicon melt 3, and finally increasing the oxygen content in the seed crystal rod 4. Due to the use of heavily doped crystal rods (resistivity less than 1Ω.cm), the oxygen content in the seed crystal rod can be increased to 20-30ppma, thereby increasing the mechanical strength of the silicon wafer. Finally, the total silicon wafer fragmentation rate in the silicon wafer processing process and the entire IC tape-out process is less than 1%, and the product quality is significantly improved, with significant economic benefits.
[0022] As a comparison, Figure 4 , which is a schematic diagram of a conventional quartz crucible and crystal growth, wherein the curved arrow is the convection direction of the silicon melt 3;
[0023] At this time, the melt rubs against the wall of the quartz crucible, and a small amount of the quartz crucible is melted. The trace oxygen Oi in the silicon melt 3 is the main source. With the CZ crystal growth process, this part of oxygen Oi becomes the main source of oxygen in the crystal rod. As time goes by, most of the oxygen Oi in the silicon melt 3 will evaporate from the liquid surface, and finally remain in the crystal rod with a low oxygen content, especially in the heavily doped crystal rod (resistivity less than 1Ω.cm), the oxygen content in the body is generally 15-30ppma. Once the oxygen content is lower than 20ppma, the mechanical strength of the silicon wafer will be low, which is easy to cause the total fragmentation rate of the back-end silicon wafer process and IC tape-out process to be as high as 2%.
[0024] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A new type of quartz crucible, characterized in that: It comprises a quartz crucible pot body for CZ method crystal growth and a silicon melt (3) for crystal growth located in the pot body, wherein a seed crystal rod (4) is placed in the pot body; The pot body comprises a pot bottom (1) and a pot wall (2) on the pot bottom (1); the pot wall (2) is arranged around the pot bottom (1) and is integrally formed with the pot bottom (1); the pot wall (2) is arranged in a circular sleeve shape with a small top and a large bottom. The angle between the cross section of the pot wall (2) and the vertical direction is 15°.
2. A novel quartz crucible according to claim 1, characterized in that: The lower end of the seed crystal rod (4) extends below the liquid surface of the silicon melt (3).