Energy-saving silicon carbide single crystal growth device with improved cooling rate

Abstract

The utility model discloses an energy -conserving silicon carbide single crystal growth device that can improve the cooling rate relates to silicon carbide crystal growth technical field, including resistance furnace, the furnace cavity inside resistance furnace is provided with the first heat preservation chamber for growing crystal and the second heat preservation chamber for cooling, and the first heat preservation chamber is located below the second heat preservation chamber, the first heat preservation chamber is surrounded through lower heat preservation layer, and the second heat preservation chamber is surrounded through upper heat preservation layer, and the thickness of lower heat preservation layer is greater than the thickness of upper heat preservation layer, the top of lower support rod is connected with the crucible, and the lower heat preservation cover is connected on lower support rod, and the top of crucible is connected with the upper heat preservation cover through upper support rod, the utility model discloses through material distinguishing functional heat preservation area, can effectively compromise energy consumption and the selection and abandonment of technology. Improve the cooling rate, optimize production efficiency, after improving cooling, the dislocation mean of substrate has obvious improvement.

Description

Technical Field

[0001] This utility model relates to the field of silicon carbide crystal growth technology, specifically to an energy-saving silicon carbide single crystal growth device that can improve the cooling rate. Background Technology

[0002] Silicon carbide is an important semiconductor material with a high melting point, excellent electrical properties, and thermal properties, making it widely used in power electronics, optoelectronics, and semiconductor devices. Resistance method for silicon carbide crystal growth is a common method for preparing large-size silicon carbide single crystals. The principle involves placing a source block (usually a polycrystalline source) containing the target material and a substrate (to receive the growing single crystal) into a reaction chamber and heating them to generate gaseous substances. These gaseous substances are then carried to the target site by an inert gas (such as argon). At the target site, the gaseous substances cool and condense to form a single crystal. A precise temperature control system regulates the temperature within the resistance furnace to ensure suitable temperature conditions for silicon carbide single crystal growth.

[0003] Currently, a typical resistance furnace hot zone includes insulation felt, a graphite heater, a graphite crucible, and internal crucible components. Generally speaking, the lower the thermal conductivity of the insulation, the better the insulation effect, the lower the power consumption for crystal growth, and the less energy consumed per growth cycle (typically around 3500-4000 degrees Celsius per growth cycle). However, the cooling rate after crystal growth is very slow, affecting production efficiency (it actually takes about 30-35 hours to cool down to room temperature). Moreover, when cooling slowly, the temperature of the crucible is higher than the temperature of the crystal, and the heat flux is mainly dissipated from the top of the crystal, which may result in higher thermal stress at the top than in other parts. Conversely, if insulation with slightly higher thermal conductivity is used, the cooling efficiency can be improved by more than 15%, but this will increase the power consumption of crystal growth by about 10%-20%. Utility Model Content

[0004] This invention overcomes the shortcomings of the prior art and proposes an energy-saving silicon carbide single crystal growth device that can improve the cooling rate; it solves the problem that the cooling rate and energy consumption cannot be satisfied at the same time during the crystal growth process.

[0005] To achieve the above objectives, this utility model is implemented through the following technical solution:

[0006] An energy-saving silicon carbide single crystal growth apparatus with improved cooling rate includes a resistance furnace. The furnace cavity contains a first insulation chamber for crystal growth and a second insulation chamber for cooling. The first insulation chamber is located below the second insulation chamber. The first insulation chamber is enclosed by a lower insulation layer, and the second insulation chamber is enclosed by an upper insulation layer. The thickness of the lower insulation layer is greater than that of the upper insulation layer. A lower support rod is slidably connected to the bottom of the furnace cavity. A crucible is connected to the top of the lower support rod, and a lower insulation cover is connected to the lower support rod. The top of the crucible is connected to an upper insulation cover via an upper support rod. Both the upper and lower insulation layers have channels through which the crucible, the upper insulation cover, and the lower insulation cover enter the first or second insulation chamber.

[0007] Furthermore, the bottom of the upper insulation layer is connected to the top of the lower insulation layer.

[0008] Furthermore, the ratio of the thickness of the lower insulation layer to the thickness of the upper insulation layer is 2 to 4:1.

[0009] Furthermore, a heater is installed inside the first insulation cavity.

[0010] Furthermore, the upper and lower insulation covers are circular, with equal diameters, and are adapted to the diameter of the channel, so that the outer walls of the upper and lower insulation covers can contact the inner wall of the channel.

[0011] Furthermore, the diameter of the crucible is smaller than the diameter of the upper insulation cover.

[0012] Furthermore, both the upper and lower insulation covers are made of hard felt.

[0013] The beneficial effects of this utility model compared to the prior art are as follows:

[0014] This invention designs two insulation chambers within a single furnace cavity. One furnace cavity is dedicated to crystal growth, while the other is dedicated to cooling. This effectively compromises energy consumption and process considerations, achieving energy saving, high efficiency, and improved crystal growth processes.

[0015] The lower insulation of this invention is used for crystal growth. The insulation is relatively thick, and the overall heat dissipation is small, which can reduce the effective power of crystal growth. When cooling down, the lower heat source has no power. The crucible is moved to the upper insulation. Because the upper insulation is thin and has a high thermal conductivity, the overall heat dissipation is fast, which can effectively reduce the heat dissipation time and increase the cooling rate.

[0016] This invention distinguishes functional insulation areas by material, effectively balancing energy consumption and process considerations. It improves cooling rate and optimizes production efficiency; furthermore, the average dislocation value of the substrate is significantly improved after cooling. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of an existing electric resistance furnace;

[0018] Figure 2 This is a cross-sectional view of the resistance furnace described in the embodiment during the crystal growth process;

[0019] Figure 3 This is a cross-sectional view of the resistance furnace during the cooling process in the embodiment;

[0020] Figure 4 These are comparison charts of the cooling time of resistance furnaces; where (4a) is an existing resistance furnace and (4b) is the resistance furnace of the embodiment.

[0021] Figure 5 This is a dislocation statistics diagram of the early stage of crystal growth using existing resistance furnaces and the resistance furnace described in the embodiments.

[0022] Figure label:

[0023] 1. Furnace cavity; 2. First insulation chamber; 3. Second insulation chamber; 4. Lower insulation layer; 5. Upper insulation layer; 6. Lower support rod; 7. Crucible; 8. Lower insulation cover; 9. Upper support rod; 10. Upper insulation cover; 11. Heater. Detailed Implementation

[0024] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer, this utility model will be further described in detail with reference to the embodiments and accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of this utility model and are not intended to limit it. The technical solution of this utility model will be described in detail below with reference to the embodiments and accompanying drawings, but the scope of protection is not limited thereto.

[0025] See Figure 2 and Figure 3 This embodiment proposes an energy-saving silicon carbide single crystal growth apparatus that can improve the cooling rate, including a cylindrical resistance furnace. The furnace cavity 1 contains a first insulation chamber 2 for crystal growth and a second insulation chamber 3 for cooling. The first insulation chamber 2 is located below the second insulation chamber 3. The first insulation chamber 2 is enclosed by a lower insulation layer 4, and the second insulation chamber 3 is enclosed by an upper insulation layer 5. The bottom of the upper insulation layer 5 is connected to the top of the lower insulation layer 4. A heater 11 is installed inside the first insulation chamber 2.

[0026] The thickness of the lower insulation layer 4 is greater than the thickness of the upper insulation layer 5; typically, the ratio of the thickness of the lower insulation layer 4 to the thickness of the upper insulation layer 5 is 2 to 4:1. This is because the lower insulation layer 4 is used for crystal growth and is thicker, thus reducing the thermal conductivity and overall heat dissipation; the upper insulation layer 5 has a thinner wall thickness and a higher thermal conductivity, which is beneficial for overall heat dissipation. In this embodiment, the ratio of the thickness of the lower insulation layer 4 to the thickness of the upper insulation layer 5 is 3:1.

[0027] The bottom of the furnace cavity 1 is slidably connected to a lower support rod 6, the bottom of which is connected to a drive motor. The top of the lower support rod 6 is connected to a crucible 7. The drive motor drives the lower support rod 6 and the crucible 7 to move upward or downward. The lower support rod 6 is connected to a lower insulation cover 8, and the top of the crucible 7 is connected to an upper insulation cover 10 via an upper support rod 9. Both the upper insulation layer 5 and the lower insulation layer 4 are provided with channels, through which the crucible 7, the upper insulation cover 10, and the lower insulation cover 8 enter the first insulation chamber 2 or the second insulation chamber 3.

[0028] In this embodiment, both the upper insulation cover 10 and the lower insulation cover 8 are circular, and their diameters are equal. The diameter of the crucible 7 is smaller than that of the upper insulation cover 10, which ensures that the crucible 7 is kept sufficiently warm. The upper insulation cover 10 and the lower insulation cover 8 are adapted to the diameter of the channel, allowing their outer walls to contact the inner wall of the channel. Both the upper insulation cover 10 and the lower insulation cover 8 are made of hard felt.

[0029] This embodiment presents the working principle of an energy-saving silicon carbide single crystal growth device that can improve the cooling rate:

[0030] Within furnace chamber 1, two insulation chambers are separated by rigid felt: a first insulation chamber 2 and a second insulation chamber 3. The first insulation chamber 2 is used for crystal growth, while the second insulation chamber 3 is used for cooling. The two chambers are physically isolated by the rigid felt, ensuring they do not interfere with each other. At the start of operation, the crucible 7 is located in the first insulation chamber 2, where crystal growth occurs under the action of the heater 11. When cooling is required after crystal growth, the lower support rod 6 is moved upwards by a drive motor, causing the crucible 7, the lower insulation cover 8, and the upper insulation cover 10 to move upwards together. The lower insulation cover 10 moves to the junction of the first insulation chamber 2 and the second insulation chamber 3; at this point, the crucible 7 is located in the second insulation chamber 3 for cooling.

[0031] See Figure 4 The figures are comparisons of the cooling time of resistance furnaces; Figure (4a) shows an existing resistance furnace, and Figure (4b) shows the resistance furnace of the embodiment. Under the conventional structure of the existing resistance furnace, the cooling time is more than 5 hours; while using the growth device described in this embodiment, the cooling time is shortened to about 3-3.5 hours.

[0032] See Figure 5This is a dislocation statistics diagram using an existing resistance furnace and the resistance furnace described in the embodiment, during the early stage of crystal growth. The results are shown in the table below:

[0033]

[0034] The above description is a further detailed explanation of the present invention in conjunction with specific preferred embodiments. It should not be considered that the specific embodiments of the present invention are limited to this. For those skilled in the art, several simple deductions or substitutions can be made without departing from the present invention, and all such deductions or substitutions should be considered to fall within the scope of patent protection determined by the submitted claims.

Claims

1. An energy-saving silicon carbide single crystal growth apparatus with improved cooling rate, comprising a resistance furnace, characterized in that, The furnace cavity (1) of the resistance furnace is provided with a first heat-insulating chamber (2) for crystal growth and a second heat-insulating chamber (3) for cooling. The first heat-insulating chamber (2) is located below the second heat-insulating chamber (3). The first heat-insulating chamber (2) is surrounded by a lower heat-insulating layer (4), and the second heat-insulating chamber (3) is surrounded by an upper heat-insulating layer (5). The thickness of the lower heat-insulating layer (4) is greater than the thickness of the upper heat-insulating layer (5). The bottom of the furnace cavity (1) is slidably connected. A lower support rod (6) is connected to the crucible (7) at the top of the lower support rod (6), and a lower insulation cover (8) is connected to the lower support rod (6). The top of the crucible (7) is connected to an upper insulation cover (10) via an upper support rod (9). Both the upper insulation layer (5) and the lower insulation layer (4) are provided with channels, through which the crucible (7), the upper insulation cover (10) and the lower insulation cover (8) enter the first insulation chamber (2) or the second insulation chamber (3).

2. The energy-saving silicon carbide single crystal growth apparatus with improved cooling rate according to claim 1, characterized in that, The bottom of the upper insulation layer (5) is connected to the top of the lower insulation layer (4).

3. The energy-saving silicon carbide single crystal growth apparatus with improved cooling rate according to claim 1, characterized in that, The ratio of the thickness of the lower insulation layer (4) to the thickness of the upper insulation layer (5) is 2~4:

1.

4. The energy-saving silicon carbide single crystal growth apparatus with improved cooling rate according to claim 1, characterized in that, A heater (11) is installed in the first heat-insulating chamber (2).

5. The energy-saving silicon carbide single crystal growth apparatus according to claim 1, characterized in that, The upper heat insulation cover (10) and the lower heat insulation cover (8) are circular, and the diameters of the upper heat insulation cover (10) and the lower heat insulation cover (8) are equal. The upper heat insulation cover (10) and the lower heat insulation cover (8) are adapted to the diameter of the channel so that the outer wall of the upper heat insulation cover (10) and the lower heat insulation cover (8) can contact the inner wall of the channel.

6. The energy-saving silicon carbide single crystal growth apparatus with improved cooling rate according to claim 5, characterized in that, The diameter of the crucible (7) is smaller than the diameter of the upper heat-insulating cover (10).

7. The energy-saving silicon carbide single crystal growth apparatus according to claim 5, characterized in that, Both the upper insulation cover (10) and the lower insulation cover (8) are hard felt covers.

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