Auxiliary furnace chamber of single crystal furnace

Abstract

The invention provides an auxiliary furnace chamber of a single crystal furnace, and belongs to the technical field of semiconductor production. Comprising an auxiliary furnace body, the interior of the auxiliary furnace body is provided with a containing space, the auxiliary furnace body comprises an inner wall and an outer wall, the inner wall divides the containing space into an auxiliary furnace chamber inner cavity and a furnace wall inner cavity, the furnace wall inner cavity is located between the inner wall and the outer wall, and cooling liquid is introduced into the furnace wall inner cavity; the temperature control mechanism is arranged in the inner cavity of the furnace wall, and the temperature control mechanism is used for controlling the local temperature of the silicon single crystal rod in the inner cavity of the auxiliary furnace chamber; the driving mechanism is connected with the temperature control mechanism, the driving mechanism is used for driving the temperature control mechanism to move in the vertical direction, and the vertical direction is perpendicular to the horizontal plane. According to the technical scheme, the standing time of the crystal bar in the single crystal furnace in a certain temperature interval during cooling can be controlled.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor production, and in particular to an auxiliary furnace chamber of a single crystal furnace. Background Art

[0002] Research shows that after a series of heat treatments, the bulk microdefect density (BMD) of silicon wafers is closely related to the thermal history of crystal growth, especially the residence time in a certain temperature range. For example, if the residence time of the crystal rod at 650℃-700℃ increases, the BMD will increase accordingly, while increasing the cooling rate of the crystal rod at 900℃-1050℃ can avoid the generation of OISF-ring (i.e. stacking fault defect).

[0003] However, it is difficult for current single crystal furnaces to control the time that the crystal rod stays in a certain temperature range while cooling. Summary of the invention

[0004] The invention provides an auxiliary furnace chamber of a single crystal furnace, which can control the residence time of a crystal rod in the single crystal furnace in a certain temperature range when cooling.

[0005] In order to achieve the above object, the technical solution adopted by the embodiment of the present invention is:

[0006] An auxiliary furnace chamber of a single crystal furnace, comprising:

[0007] The auxiliary furnace body has a containing space inside, and the auxiliary furnace body comprises: an inner wall and an outer wall, the inner wall divides the containing space into an auxiliary furnace chamber inner cavity and a furnace wall inner cavity, the furnace wall inner cavity is located between the inner wall and the outer wall, and a coolant flows in the furnace wall inner cavity;

[0008] A temperature control mechanism is arranged in the inner cavity of the furnace wall, and the temperature control mechanism is used to control the local temperature of the single crystal silicon rods in the inner cavity of the auxiliary furnace chamber;

[0009] A driving mechanism is connected to the temperature control mechanism, and is used to drive the temperature control mechanism to move in a vertical direction, wherein the vertical direction is perpendicular to a horizontal plane.

[0010] In some embodiments, the temperature control mechanism includes:

[0011] Inlet pipe, spiral pipe and outlet pipe;

[0012] Wherein, the spiral tube spirally surrounds a part of the outer circumference of the inner wall;

[0013] The two ends of the spiral tube are respectively connected to the first end of the water inlet pipe and the first end of the water outlet pipe, and the spiral tube is connected to the water inlet pipe and the water outlet pipe;

[0014] A coolant with a target temperature circulates in the temperature control mechanism, wherein the second end of the water inlet pipe is a water inlet, and the second end of the water outlet pipe is a water outlet.

[0015] In some embodiments, the auxiliary furnace chamber further comprises:

[0016] A cover body is installed above the auxiliary furnace body, and a first mounting hole and a second mounting hole are opened on the cover body;

[0017] Wherein, the second end of the water inlet pipe extends from the first mounting hole to the outside of the auxiliary furnace chamber;

[0018] The second end of the water outlet pipe extends from the second installation hole to the outside of the inner cavity of the auxiliary furnace chamber.

[0019] In some embodiments, the cover is a flange.

[0020] In some embodiments, the driving mechanism is connected to the water inlet pipe and the water outlet pipe respectively;

[0021] Wherein, the driving mechanism is used to drive the water inlet pipe and the water outlet pipe to move in the vertical direction, so as to drive the spiral tube to move in the vertical direction.

[0022] In some embodiments, the auxiliary furnace chamber further comprises:

[0023] The temperature monitoring device is arranged in the inner cavity of the auxiliary furnace chamber and fixed on the inner wall.

[0024] In some embodiments, the inner cavity of the auxiliary furnace is divided into at least two temperature control zones, each of which is provided with at least one temperature monitoring device, and the temperature monitoring device is used to monitor the surface temperature of the single crystal silicon rod located in the temperature control zone where the temperature monitoring device is located.

[0025] In some embodiments, the auxiliary furnace chamber of the single crystal furnace further includes:

[0026] A controller connected to the temperature monitoring device;

[0027] Wherein, the controller is used for:

[0028] Acquiring temperature data of the temperature monitoring device;

[0029] According to the temperature data, the driving mechanism is controlled to drive the temperature control mechanism to move in the vertical direction to a target temperature control area, and the temperature of the temperature control mechanism is controlled to adjust the temperature of the single crystal silicon rod located in the target temperature control area, and the target temperature control area is one of the at least two temperature control areas.

[0030] In some embodiments, the water inlet pipe and the water outlet pipe are made of stainless steel.

[0031] In some embodiments, the spiral tube is made of stainless steel.

[0032] The beneficial effects of the present invention are:

[0033] In this embodiment, the auxiliary furnace chamber includes an auxiliary furnace body, a temperature control mechanism and a driving mechanism. The temperature control mechanism can be driven by the driving mechanism to move in the vertical direction to realize local temperature control of the single crystal silicon rod, thereby achieving the technical effect of controlling the cooling time of the single crystal silicon rod in a certain temperature range. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic diagram showing the relationship between the crystal ingot temperature range and the crystal ingot structure;

[0035] Figure 2 A schematic diagram showing a single crystal silicon rod being processed in an auxiliary furnace chamber of a single crystal furnace according to an embodiment of the present invention;

[0036] Figure 3 A schematic diagram showing temperature regulation in the auxiliary furnace chamber of a single crystal furnace according to an embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0038] like Figure 1 As shown, the structure of the crystal rod in different temperature ranges is shown. The hollow circle represents Vacancy, the black solid circle represents Self-interstital, the hollow ellipse represents D-defects, the solid ellipse represents A-defects, and the gray solid circle represents Oxygen precipitate.

[0039] In order to solve the above technical problems, an embodiment of the present invention provides an auxiliary furnace chamber of a single crystal furnace, which can control the residence time of a crystal rod in a certain temperature range when cooling in the single crystal furnace.

[0040] like Figure 2 As shown, an embodiment of the present invention provides an auxiliary furnace chamber of a single crystal furnace, comprising:

[0041] Auxiliary furnace body 1, temperature control mechanism 2 and driving mechanism 4.

[0042] Among them, the auxiliary furnace body 1 has an accommodating space inside, and the auxiliary furnace body 1 includes: an inner wall 101 and an outer wall 102, the inner wall 101 divides the accommodating space into an auxiliary furnace chamber inner cavity 103 and a furnace wall inner cavity 104, the furnace wall inner cavity 104 is located between the inner wall 101 and the outer wall 102, and the furnace wall inner cavity 104 is filled with cooling liquid.

[0043] It should be noted that the coolant in the furnace wall cavity 104 is used to adjust the temperature of the auxiliary furnace chamber of the single crystal furnace.

[0044] The temperature control mechanism 2 is arranged in the furnace wall inner cavity 104 , and the temperature control mechanism 2 is used to control the local temperature of the single crystal silicon rod 3 in the auxiliary furnace chamber inner cavity 103 .

[0045] The driving mechanism 4 is connected to the temperature control mechanism 2, and is used to drive the temperature control mechanism 2 to move in a vertical direction, where the vertical direction is perpendicular to a horizontal plane.

[0046] In this embodiment, the auxiliary furnace chamber includes an auxiliary furnace body 1, a temperature control mechanism 2 and a driving mechanism 4. The driving mechanism 4 can drive the temperature control mechanism 2 to move in the vertical direction to achieve local temperature control of the single crystal silicon rod, thereby achieving the technical effect of controlling the cooling time of the single crystal silicon rod in a certain temperature range.

[0047] In some embodiments, the temperature control mechanism 2 includes: a water inlet pipe 201, a spiral tube 202 and a water outlet pipe 203; wherein the spiral tube 202 is spirally wrapped around the local periphery of the inner wall 101; the two ends of the spiral tube 202 are respectively connected to the first end of the water inlet pipe 201 and the first end of the water outlet pipe 203, and the spiral tube 202 connects the water inlet pipe 201 and the water outlet pipe 203; a coolant with a target temperature circulates in the temperature control mechanism, wherein the second end of the water inlet pipe 201 is a water inlet, and the second end of the water outlet pipe 203 is a water outlet.

[0048] It should be noted that if Figure 2 As shown, a coolant can be introduced into the pipe from the second end (that is, the water inlet) of the water inlet pipe 201, and the coolant sequentially passes through the water inlet pipe 201, the spiral tube 202 and the water outlet pipe 203, and flows out from the second end (that is, the water outlet) of the water outlet pipe 203. In this way, the temperature of the temperature control mechanism 2 is controlled by controlling the temperature of the coolant flowing into the temperature control mechanism 2 (that is, injecting the coolant of the target temperature into the temperature control mechanism), further affecting the temperature of the accommodation space in the inner wall 101 surrounded by the spiral tube 202, and finally achieving the effect of controlling the local temperature of the single crystal silicon rod 3 in the inner cavity 103 of the auxiliary furnace chamber.

[0049] In a specific example, the water inlet pipe 201 and the water outlet pipe 203 can be made of stainless steel; the spiral tube 202 can also be made of stainless steel. Here, the stainless steel material is not easy to rust and can also ensure good thermal conductivity. Specifically, the stainless steel material can be 304 stainless steel.

[0050] In some embodiments, the auxiliary furnace chamber further comprises: a cover 5, mounted above the auxiliary furnace body 1, and a first mounting hole and a second mounting hole are formed on the cover 5; wherein the second end of the water inlet pipe 201 extends from the first mounting hole to the outside of the auxiliary furnace chamber inner cavity 103; and the second end of the water outlet pipe 203 extends from the second mounting hole to the outside of the auxiliary furnace chamber inner cavity 103. In a specific example, the cover 5 is a flange.

[0051] like Figure 2 As shown, one end of the crystal rope 9 is fixed on the cover 5, and the other end is connected to the seed crystal chuck 7. The seed crystal chuck 7 is used to fix the seed crystal 8. The single crystal silicon rod 3 grows out of the seed crystal 8 and is located in the accommodating space of the auxiliary furnace chamber.

[0052] In some embodiments, the driving mechanism 4 is connected to the water inlet pipe 201 and the water outlet pipe 203 respectively; wherein, the driving mechanism 4 is used to drive the water inlet pipe 201 and the water outlet pipe 203 to move in the vertical direction, so as to drive the spiral tube 202 to move in the vertical direction.

[0053] In this way, according to the temperature regulation requirements of the single crystal silicon rod 3, a coolant of a specific temperature can be introduced into the spiral tube 202 through the water inlet pipe 201, and the spiral tube 202 can be raised or lowered to the position where the temperature of the single crystal silicon rod 3 needs to be adjusted through the driving mechanism 4, so as to change the local temperature gradient distribution in the auxiliary furnace chamber of the single crystal furnace, thereby realizing local temperature control of the single crystal silicon rod 3 and achieving the technical effect of controlling the cooling time of the single crystal silicon rod 3 in a certain temperature range.

[0054] like Figure 3 As shown, the abscissa represents temperature, and the ordinate represents the position on the single crystal silicon rod 3 . Curve 10 can reflect the temperature influence of the spiral tube 202 on the single crystal silicon rod 3 .

[0055] In this embodiment, the water inlet pipe 201 and the water outlet pipe 203 can be driven to move in the vertical direction by the driving mechanism 4, so as to realize the lifting and lowering of the spiral tube 202. Since the spiral tube 202 surrounds the local periphery of the inner wall 101, the local temperature of the single crystal silicon rod 3 in the inner cavity 103 of the auxiliary furnace chamber can be controlled by lifting and lowering the spiral tube 202.

[0056] In some embodiments, the auxiliary furnace chamber further includes: a temperature monitoring device 6 , which is disposed in the inner cavity 103 of the auxiliary furnace chamber and fixed on the inner wall 101 .

[0057] In this embodiment, the temperature monitoring device 6 can be used to monitor the temperature of the environment in which it is located, so that temperature data can be provided as a basis for adjusting the temperature of the single crystal silicon rod 3.

[0058] In some embodiments, the inner cavity 103 of the auxiliary furnace is divided into at least two temperature control zones, each of which is provided with at least one temperature monitoring device 6, and the temperature monitoring device 6 is used to monitor the surface temperature of the single crystal silicon rod 3 located in the temperature control zone where the temperature monitoring device 6 is located.

[0059] For example, Figure 2 As shown, in a specific embodiment of the present invention, the inner cavity 103 of the auxiliary furnace is divided into three temperature control areas, and a temperature monitoring device 6 is installed in each temperature control area to realize the temperature monitoring function of the single crystal silicon rod 3 located in each temperature control area.

[0060] It should be noted that the temperature monitoring device 6 can be connected to the operation panel of the crystal pulling furnace, so that the temperature monitoring device 6 can feed back the temperature data obtained by monitoring to the operation panel, so that the operation panel can display the temperature data for relevant personnel to view.

[0061] In some embodiments, the auxiliary furnace chamber of the single crystal furnace also includes: a controller, connected to the temperature monitoring device 6; wherein the controller is used to: obtain temperature data of the temperature monitoring device 6; according to the temperature data, control the driving mechanism 4 to drive the temperature control mechanism 2 to move in the vertical direction to the target temperature control area, and control the temperature of the temperature control mechanism 2 to adjust the temperature of the single crystal silicon rod 3 located in the target temperature control area, and the target temperature control area is one of the at least two temperature control areas.

[0062] It should be noted that the temperature of the temperature control mechanism 2 can be controlled by controlling the temperature of the coolant injected into the temperature control mechanism 2 .

[0063] In this embodiment, the controller can control the temperature gradient of the single crystal silicon rod 3 in a specific temperature range by controlling the temperature of the temperature control mechanism 2 .

[0064] Here, the application of the embodiment of the present invention is described in combination with specific scenarios:

[0065] In a specific embodiment of the present invention, 650°C-700°C is an ideal temperature range for controlling BMD. If a crystal rod with a higher BMD (such as a single crystal silicon rod 3) is required, the driving mechanism 4 is controlled to drive the temperature control mechanism 2 to raise and lower the spiral tube 202 to a position on the single crystal silicon rod 3 in the range of 650°C-700°C, and a higher temperature coolant (for example, 40°C~50°C) is introduced into the temperature control mechanism 2, so that the residence time of the single crystal silicon rod 3 in the temperature range is increased, thereby achieving the effect of increasing the BMD amount in the single crystal silicon rod 3.

[0066] On the contrary, if a crystal rod with lower BMD is required, the control driving mechanism 4 drives the temperature control mechanism 2 to raise and lower the spiral tube 202 to a position in the range of 650°C-700°C on the single crystal silicon rod 3, and a lower temperature coolant (for example, 10°C~20°C) is introduced into the temperature control mechanism 2, so that the residence time of the single crystal silicon rod 3 in this temperature range is shortened, thereby achieving the effect of reducing the BMD amount in the single crystal silicon rod 3.

[0067] In this embodiment, the cooling temperature can be changed by introducing a coolant of a higher temperature or a lower temperature into the temperature control mechanism 2 to control the residence time of the single crystal silicon rod 3 in the temperature range of 650° C.-700° C.

[0068] Similarly, 900°C-1050°C is the temperature range for defect generation. By introducing a coolant with a lower temperature into the temperature control mechanism 2, the residence time of the single crystal silicon rod 3 in this temperature range can be shortened, thereby achieving the effect of reducing the probability of OISF-ring generation.

[0069] Experiments have shown that the BMD level without temperature fine-tuning by the temperature control mechanism of the embodiment of the present invention is: (2.50E+09)ea / cm3, the BMD level after higher temperature fine-tuning by the temperature control mechanism of the embodiment of the present invention is: (3.00E+09)ea / cm3, and the BMD level after lower temperature fine-tuning by the temperature control mechanism of the embodiment of the present invention is: (2.00E+09)ea / cm3.

[0070] It can be seen that the BMD level after fine-tuning at a higher temperature is higher than the normal BMD level, and the BMD level after fine-tuning at a lower temperature is lower than the normal BMD level.

[0071] In addition, the probability of OIS F-ring (ie, stacking fault defect) without temperature fine-tuning by the temperature control mechanism of the embodiment of the present invention is 33%, and the probability of OIS F-ring after temperature fine-tuning by the temperature control mechanism of the embodiment of the present invention is 25%.

[0072] It can be seen that the probability of OIS F-ring occurring in the single crystal silicon rod 3 after temperature fine-tuning is lower than the normal level.

[0073] In this embodiment, according to the temperature regulation requirement of the single crystal silicon rod 3, a coolant of a specific temperature can be introduced into the spiral tube 202 through the water inlet pipe 201, and the spiral tube 202 can be raised or lowered to the position where the temperature of the single crystal silicon rod 3 needs to be adjusted through the driving mechanism 4, so as to change the local temperature gradient in the auxiliary furnace chamber of the single crystal furnace, thereby realizing local temperature control of the single crystal silicon rod 3 and achieving the technical effect of controlling the cooling time of the single crystal silicon rod 3 in a certain temperature range.

[0074] It should be noted that each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the embodiments, since they are basically similar to the product embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the product embodiments.

[0075] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0076] It will be understood that when an element such as a layer, film, region, or substrate is referred to as being “on” or “under” another element, it can be “directly on” or “under” the other element or intervening elements may be present.

[0077] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0078] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A secondary furnace chamber of a single crystal furnace, characterized in that: include: An auxiliary furnace body (1) has a storage space inside, the auxiliary furnace body (1) comprising: an inner wall (101) and an outer wall (102), the inner wall (101) dividing the storage space into an auxiliary furnace chamber inner cavity (103) and a furnace wall inner cavity (104), the furnace wall inner cavity (104) being located between the inner wall (101) and the outer wall (102), and a cooling liquid passing through the furnace wall inner cavity (104); A temperature control mechanism (2) is arranged in the furnace wall inner cavity (104), and the temperature control mechanism (2) is used to control the local temperature of the single crystal silicon rod (3) in the auxiliary furnace chamber inner cavity (103); A driving mechanism (4) is connected to the temperature control mechanism (2), and the driving mechanism (4) is used to drive the temperature control mechanism (2) to move in a vertical direction, wherein the vertical direction is perpendicular to a horizontal plane.

2. The auxiliary furnace chamber of the single crystal furnace according to claim 1, characterized in that: The temperature control mechanism (2) comprises: A water inlet pipe (201), a spiral pipe (202) and a water outlet pipe (203); Wherein, the spiral tube (202) spirally surrounds a part of the outer circumference of the inner wall (101); The two ends of the spiral tube (202) are respectively connected to the first end of the water inlet pipe (201) and the first end of the water outlet pipe (203), and the spiral tube (202) is in communication with the water inlet pipe (201) and the water outlet pipe (203); A coolant with a target temperature circulates in the temperature control mechanism, wherein the second end of the water inlet pipe (201) is a water inlet, and the second end of the water outlet pipe (203) is a water outlet.

3. The auxiliary furnace chamber of the single crystal furnace according to claim 2, characterized in that: Also includes: A cover body (5) is installed above the auxiliary furnace body (1), and a first mounting hole and a second mounting hole are formed on the cover body (5); Wherein, the second end of the water inlet pipe (201) extends from the first installation hole to the outside of the inner cavity (103) of the auxiliary furnace chamber; The second end of the water outlet pipe (203) extends from the second installation hole to the outside of the inner cavity (103) of the auxiliary furnace chamber.

4. The auxiliary furnace chamber of the single crystal furnace according to claim 3, characterized in that: The cover body (5) is a flange.

5. The auxiliary furnace chamber of the single crystal furnace according to claim 3, characterized in that: The driving mechanism (4) is connected to the water inlet pipe (201) and the water outlet pipe (203) respectively; Wherein, the driving mechanism (4) is used to drive the water inlet pipe (201) and the water outlet pipe (203) to move in the vertical direction, so as to drive the spiral tube (202) to move in the vertical direction.

6. The auxiliary furnace chamber of the single crystal furnace according to claim 1, characterized in that: Also includes: A temperature monitoring device (6) is arranged in the inner cavity (103) of the auxiliary furnace chamber and fixed on the inner wall (101).

7. The auxiliary furnace chamber of the single crystal furnace according to claim 6, characterized in that: The inner cavity (103) of the auxiliary furnace chamber is divided into at least two temperature control areas, each of which is provided with at least one temperature monitoring device (6), and the temperature monitoring device (6) is used to monitor the surface temperature of the single crystal silicon rod (3) located in the temperature control area where the temperature monitoring device (6) is located.

8. The auxiliary furnace chamber of the single crystal furnace according to claim 7, characterized in that: Also includes: A controller connected to the temperature monitoring device (6); Wherein, the controller is used for: Acquiring temperature data of the temperature monitoring device (6); According to the temperature data, the driving mechanism (4) is controlled to drive the temperature control mechanism (2) to move in the vertical direction to a target temperature control area, and the temperature of the temperature control mechanism (2) is controlled to adjust the temperature of the single crystal silicon rod (3) located in the target temperature control area, wherein the target temperature control area is one of the at least two temperature control areas.

9. The auxiliary furnace chamber of the single crystal furnace according to claim 2, characterized in that: The water inlet pipe (201) and the water outlet pipe (203) are made of stainless steel.

10. The auxiliary furnace chamber of the single crystal furnace according to claim 2, characterized in that: The spiral tube (202) is made of stainless steel.

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