Efficient doping bell jar for semiconductor single crystal

Abstract

The efficient doping bell jar comprises a jar body and a height fixing assembly, the jar body comprises a straight cylinder section and a flow guide section, the flow guide section is located below the straight cylinder section, the flow guide section is provided with a first expansion section and a second expansion section which are connected, the first expansion section is connected with the straight cylinder section, and the second expansion section is connected with the first expansion section. The first expansion section and the second expansion section are used for gradually expanding the caliber of the cover body; the height fixing assembly is connected to the cover body, the lower end of the height fixing assembly extends to the position below the cover body, and the height fixing assembly is used for determining the distance between the lower edge of the cover body and the silicon melt liquid level. The area of the opening in the lower end of the cover body is increased through the first expansion section and the second expansion section, so that arsenic gas has more opportunities to be in contact with molten silicon, and the doping efficiency is improved; the opening of the structure is expanded, rebounding turbulent flow caused by the fact that argon is directly blown to silicon molten soup in the crystal growth process through the CZ method is avoided, the flow guiding section plays a role in guiding airflow, and therefore the crystal growth efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor crystal growth, in particular to a high-efficiency doping bell jar for semiconductor arsenic single crystal. Background Art

[0002] Gas phase doping is the main doping method for the growth of semiconductor arsenic single crystal CZ. Arsenic doping is gas phase doping. The gas after arsenic sublimation contacts with molten silicon and enters the interior of molten silicon through diffusion to achieve doping. The bell jar is an important tool in the process of arsenic gas phase doping. The design of the bell jar has a direct impact on the arsenic doping efficiency.

[0003] During the crystal growth process using the CZ method, the argon gas in the conventional straight bell jar will inevitably blow directly onto the surface of the solution, causing rebound turbulence and reducing the efficiency of arsenic doping. Utility Model Content

[0004] The embodiment of the present application provides a high-efficiency doping bell jar for a semiconductor single crystal, which is used to solve the problem of reduced arsenic doping rate in a straight-cylindrical doping bell jar due to rebound turbulence.

[0005] The embodiment of the present application provides a high-efficiency doping bell jar for a semiconductor single crystal, comprising:

[0006] A cover body, the cover body comprising a straight tube section and a guide section, the guide section is located below the straight tube section, the guide section has a first expansion section and a second expansion section connected to each other, the first expansion section is connected to the straight tube section, the second expansion section is connected to the first expansion section, and the first expansion section and the second expansion section are used to gradually expand the diameter of the cover body;

[0007] A height determination component is connected to the cover body, and the lower end of the height determination component extends to below the cover body. The height determination component is used to determine the distance between the lower edge of the cover body and the silicon melt liquid surface.

[0008] The beneficial effects of the above-mentioned embodiment are as follows: the opening area of ​​the lower end of the cover body is increased by the first expansion section and the second expansion section, so that the arsenic gas has more opportunities to contact with the silicon melt, thereby improving the doping efficiency; the opening of the expansion structure avoids the rebound turbulence caused by argon gas directly blowing onto the silicon melt during the CZ method crystal growth process, and the guide section guides the airflow, thereby improving the crystal growth efficiency; the height-fixing component facilitates the operator to determine the distance between the lower edge of the cover body and the silicon melt liquid surface.

[0009] Based on the above embodiments, the embodiments of the present application may also be improved as follows:

[0010] In one embodiment of the present application: the change speed of the cross-sectional area of ​​the first expansion section gradually increases, and the change speed of the cross-sectional area of ​​the second expansion section gradually decreases, and the first expansion section and the second expansion section are streamlined structures. The beneficial effect of this step is: reducing the change speed of the cross-sectional area of ​​the second expansion section, so that the change of the inner wall of the second expansion section tends to be gentle, avoiding violent collision of gas, and cooperating with the streamlined structure to improve the guiding effect of airflow.

[0011] In one embodiment of the present application: the height setting assembly includes: a height setting rod, having a plug-in end and a positioning end, the plug-in end is inserted into the corresponding plug-in hole of the cover body, and the positioning end extends to the bottom of the cover body; a positioning member, which is sleeved on the plug-in end and fits the inner wall of the cover body; a connecting member, which is connected to the plug-in end and positions the positioning member. The beneficial effect of this step: through the cooperation of the connecting member and the positioning member, the height setting member can be stably connected to the cover body.

[0012] In one embodiment of the present application: the height-fixing rod further has a positioning portion, and the positioning portion is in contact with the outer wall of the housing. The beneficial effect of this step: the positioning portion cooperates with the positioning member to improve the stability of the positioning of the height-fixing rod.

[0013] In one embodiment of the present application: the connector is threadedly connected to the plug end. Beneficial effect of this step: the threaded structure facilitates the disassembly and assembly of the height setting component. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the specific implementation of the utility model or the technical solution in the prior art, the following is a brief introduction to the drawings required for the specific implementation or the prior art description. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual scale.

[0015] Figure 1 It is a schematic diagram of the structure of a high-efficiency doping bell jar for semiconductor single crystal;

[0016] Figure 2 It is a structural diagram of the height setting component.

[0017] Among them, 101 is a first expansion section, 102 is a second expansion section, and 103 is a plug hole;

[0018] 2 height fixing assembly, 201 height fixing rod, 202 positioning piece, 203 connecting piece, 204 positioning part, 205 connecting part, 206 plug-in part, 207 positioning hole. DETAILED DESCRIPTION

[0019] In this application, unless otherwise clearly specified and limited, the terms in this application should be understood in a broad sense, such as connection can be fixed connection, detachable connection or integration, direct connection or indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of different terms in this utility model can be understood according to specific circumstances, and the scope of the specific meaning should be limited to realizing the functions of this application.

[0020] like Figure 1 , 2 As shown, a high-efficiency doping bell jar for semiconductor single crystal comprises: a jar body 1 and a height-fixing assembly 2, wherein the jar body 1 comprises a straight tube section and a guide section, the guide section is located below the straight tube section, the guide section comprises a first expansion section 101 and a second expansion section 102 connected to each other, the first expansion section 101 is connected to the straight tube section, the second expansion section 102 is connected to the first expansion section 101, the first expansion section 101 and the second expansion section 102 are used to gradually expand the diameter of the jar body 1; the height-fixing assembly 2 is connected to the jar body 1, the lower end of the height-fixing assembly 2 extends to below the jar body 1, and the height-fixing assembly 2 is used to determine the distance between the lower edge of the jar body 1 and the surface of the silicon melt.

[0021] In some embodiments of the present application, Figure 1 As shown, the change rate of the cross-sectional area of ​​the first expansion section 101 gradually increases, and the change rate of the cross-sectional area of ​​the second expansion section 102 gradually decreases. The cross sections of the first expansion section 101 and the second expansion section 102 are both circular structures, which reduces the change rate of the cross-sectional area of ​​the second expansion section 102, so that the change of the inner wall of the second expansion section 102 tends to be gentle, thereby avoiding the gas from violently colliding with the inner wall of the cover body 1 during movement; in the direction from top to bottom, the first expansion section 101 and the second expansion section 102 are streamlined change structures, thereby avoiding sudden changes in the structure, thereby improving the smoothness of gas flow and improving the airflow guidance effect.

[0022] In some embodiments of the present application, Figure 2 As shown, the height determining component 2 includes: a height determining rod 201, a positioning member 202, and a connecting member 203. The height determining rod 201 has a plug-in end and a positioning end. The plug-in end is inserted into the corresponding plug-in hole 103 opened on the cover body 1, and the positioning end extends to the bottom of the cover body 1. The positioning member 202 is sleeved on the plug-in end and fits with the inner wall of the cover body 1. The connecting member 203 is connected to the plug-in end and positions the positioning member 202. Through the cooperation of the connecting member 203 and the positioning member 202, the height determining member can be stably connected to the cover body 1.

[0023] In some embodiments of the present application, Figure 2 As shown, the height-determining rod 201 further has a positioning portion 204 , and the positioning portion 204 is in contact with the outer wall of the cover body 1 . The positioning portion 204 cooperates with the positioning member 202 , thereby improving the stability of the positioning of the height-determining rod 201 .

[0024] In some embodiments of the present application, the connector 203 is threadedly connected to the plug-in end, and the threaded structure facilitates the disassembly and assembly of the height-fixing component 2 .

[0025] In some embodiments of the present application, Figure 1 , 2 As shown, the height-setting rod 201 is made of quartz material, and the height-setting rod 201 is an inverted L-shaped structure. The lateral sides of the height-setting rod 201 include a connecting portion 205, a plug-in portion 206, and a positioning portion 204 in sequence. The connecting portion 205 has an external thread, and the connecting piece 203 is a regular hexagonal structure with a threaded hole. The connecting piece 203 is threadedly connected to the connecting portion 205 through the threaded hole. By designing the connecting piece 203 as a regular hexagonal structure, it is convenient for operators to disassemble and assemble the connecting piece 203 with a wrench; the plug-in portion 206 is a cylindrical structure, and the cover body 1 is provided with a matching cylindrical plug-in hole 103 corresponding to the plug-in portion 206. The plug-in portion 206 is slidably inserted in the plug-in hole 103, and the length of the plug-in portion 206 is greater than the plug-in hole 103. The hole 103 is deep, and a positioning hole 207 is also opened on the positioning piece 202 corresponding to the plug-in portion 206, and the plug-in portion 206 is also inserted into the positioning hole 207. The surface of the positioning piece 202 facing the inner wall of the cover body 1 has a shape matching the inner wall, and the surface of the positioning portion 204 facing the outer wall of the cover body 1 has a shape matching the outer wall of the cover body 1. The positioning piece 202 and the positioning portion 204 form a clamping structure inside and outside the cover body 1, so that the height determining rod 201 can be stably assembled on the cover body 1, and the lower end of the height determining rod 201 extends to 5 mm from the lower edge of the cover body 1. The lower end of the height determining rod 201 contacts the surface of the silicon melt, which is convenient for the operator to position the cover body 1 at a suitable height, so as to facilitate the diffusion of arsenic gas into the silicon melt.

[0026] When the modified semiconductor single crystal high-efficiency doping bell jar is in use, the opening area of ​​the lower end of the jar body 1 is increased by the first expansion section 101 and the second expansion section 102, so that the arsenic gas has more opportunities to contact with the silicon melt and increase the chance of entering the silicon melt, thereby improving the doping efficiency. At the same time, the opening of the expansion structure avoids the rebound turbulence caused by argon gas directly blowing onto the silicon melt during the CZ method crystal growth process. The guide section guides the airflow, better takes away the arsenic volatiles that have not entered the silicon melt, and avoids the arsenic volatiles from gathering above the liquid surface to form particulate pollution, thereby improving the crystal growth efficiency.

[0027] The above are only embodiments of the utility model. The common sense such as the known specific structures and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field are aware of all the common technical knowledge in the technical field to which the utility model belongs before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement the scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for the ordinary technicians in the relevant field to implement this application. It should be pointed out that for the technicians in this field, without departing from the structure of the utility model, several deformations and improvements can be made, which should also be regarded as the protection scope of the utility model, and these will not affect the effect of the implementation of the utility model and the practicality of the patent.

Claims

1. A high-efficiency doping bell jar for semiconductor single crystal, characterized in that: include: A cover body, the cover body comprising a straight tube section and a guide section, the guide section is located below the straight tube section, the guide section has a first expansion section and a second expansion section connected to each other, the first expansion section is connected to the straight tube section, the second expansion section is connected to the first expansion section, and the first expansion section and the second expansion section are used to gradually expand the diameter of the cover body; A height determination component is connected to the cover body, and the lower end of the height determination component extends to below the cover body. The height determination component is used to determine the distance between the lower edge of the cover body and the surface of the silicon melt.

2. The high-efficiency doping bell jar for semiconductor single crystal according to claim 1, characterized in that: The change speed of the cross-sectional area of ​​the first expansion section gradually increases, and the change speed of the cross-sectional area of ​​the second expansion section gradually decreases. The first expansion section and the second expansion section are streamlined structures.

3. The high-efficiency doping bell jar for semiconductor single crystal according to claim 1, characterized in that: The height setting component comprises: A height-fixing rod, comprising a plug-in end and a positioning end, wherein the plug-in end is inserted into a corresponding plug-in hole of the cover body, and the positioning end extends to the bottom of the cover body; A positioning piece, which is sleeved on the plug-in end and fits against the inner wall of the cover; A connecting piece is connected to the plug end and positions the positioning piece.

4. The high-efficiency doping bell jar for semiconductor single crystal according to claim 3, characterized in that: The height-fixing rod also has a positioning portion, and the positioning portion is in contact with the outer wall of the cover.

5. The high-efficiency doping bell jar for semiconductor single crystal according to claim 3, characterized in that: The connecting piece is threadedly connected to the plug-in end.

Images