阅读说明：本技术 单晶炉加热装置、单晶炉及单晶炉的加热方法 (Single crystal furnace heating device, single crystal furnace and heating method of single crystal furnace ) 是由 蒲以松 于 2020-05-27 设计创作，主要内容包括：本发明公开了一种单晶炉加热装置、单晶炉及单晶炉的加热方法,单晶炉加热装置包括第一加热结构,且沿周向第一加热结构的上端部至下端部的高度一致；第二加热结构,位于第一加热结构下方；第三加热结构,位于第二加热结构下方；第一加热结构的加热控制机构与第二加热结构、第三加热结构的加热控制机构不同,且第一加热结构的高度满足在等径生长阶段坩埚中的熔液处于第一加热结构的高度范围内。本发明第一加热结构的上端部至第一加热结构的下端部的高度一致,在等径生长阶段第一加热结构提供的热量能使熔液维持熔融状态,使熔液中和固液界面处有足够的纵向温度梯度,保持整个等径过程平稳进行,保证固液界面波动很小,从而保证晶棒的质量。(The invention discloses a single crystal furnace heating device, a single crystal furnace and a heating method of the single crystal furnace, wherein the single crystal furnace heating device comprises a first heating structure, and the heights from the upper end part to the lower end part of the first heating structure are consistent along the circumferential direction; the second heating structure is positioned below the first heating structure; the third heating structure is positioned below the second heating structure; the heating control mechanism of the first heating structure is different from the heating control mechanisms of the second heating structure and the third heating structure, and the height of the first heating structure meets the condition that the molten liquid in the crucible in the equal-diameter growth stage is within the height range of the first heating structure. The height from the upper end part of the first heating structure to the lower end part of the first heating structure is consistent, the melt can be maintained in a molten state by the heat provided by the first heating structure in the equal-diameter growth stage, so that sufficient longitudinal temperature gradient exists in the melt and at a solid-liquid interface, the whole equal-diameter process is kept to be stably carried out, the fluctuation of the solid-liquid interface is ensured to be small, and the quality of the crystal bar is ensured.)

1. A heating device of a single crystal furnace is characterized by comprising:

the first heating structure is arranged around the crucible, and the heights from the upper end part to the lower end part of the first heating structure are consistent along the circumferential direction;

the second heating structure is arranged around the crucible and positioned below the first heating structure, and a first gap channel is arranged between the upper end part of the second heating structure and the lower end part of the first heating structure;

the third heating structure is positioned below the second heating structure, and the third heating structure is connected with the lower end part of the second heating structure to form a heating cavity;

the heating control mechanism of the first heating structure is different from the heating control mechanisms of the second heating structure and the third heating structure, and the height of the first heating structure meets the condition that the molten liquid in the crucible in the equal-diameter growth stage is within the height range of the first heating structure.

2. The single crystal furnace heating apparatus according to claim 1, wherein the first heating structure has a height such that a part of the melt in the crucible in the isometric growth stage is within a height range below a radial high temperature line of the first heating structure, which corresponds to a position where the temperature is highest in an axial direction of the first heating structure, and another part of the melt is within a height range above the radial high temperature line of the first heating structure.

3. The heating apparatus of a single crystal furnace according to claim 2, wherein the height of the first heating structure is such that a lower half of the melt in the crucible in the isometric growth stage is within a height range below a radial high temperature line of the first heating structure and an upper half thereof is within a height range above the radial high temperature line of the first heating structure.

4. The single crystal furnace heating device of claim 3, wherein the ratio of the height of the first heating structure to the height of the second heating structure ranges from 1:1 to 2: 1.

5. The single crystal furnace heating device according to claim 1, wherein a plurality of first U-shaped heating units are uniformly arranged along the circumferential direction on the first heating structure;

a plurality of second U-shaped heating units which are uniformly distributed along the circumferential direction are arranged on the second heating structure;

the third heating structure is provided with a plurality of slot groups which are arranged at intervals around the central axis of the second heating structure, a third gap channel is arranged at the central position of the third heating structure, the slot groups are communicated with the third gap channel, and a plurality of second connecting holes are also formed in the third heating structure;

the lower end part of the first heating structure is further provided with a heater pin, the heater pin is positioned in the side groove of the second heating structure and the bottom groove of the third heating structure, a second gap channel is arranged between the heater pin and the side groove of the second heating structure and the bottom groove of the third heating structure, and the heater pin is further provided with a first connecting hole.

6. The single crystal furnace heating device according to claim 5, wherein the first U-shaped heating unit is formed by a portion of the first heating structure between two adjacent first grooves, and a second groove is further provided at a middle position between two adjacent first grooves, wherein the first grooves are grooves extending from a lower end portion to an upper end portion of the first heating structure, and the second grooves are grooves extending from the upper end portion to the lower end portion of the first heating structure;

the second U-shaped heating unit is formed by a part between two adjacent third grooves on the second heating structure, and a fourth groove is further arranged in the middle of the two adjacent third grooves, wherein the third groove is a groove extending from the lower end part to the upper end part of the second heating structure, and the fourth groove is a groove extending from the upper end part to the lower end part of the second heating structure;

the length of the first groove is smaller than that of the second groove, the width of the first groove is equal to that of the second groove, the length of the third groove is smaller than that of the fourth groove, the width of the third groove is equal to that of the fourth groove, and the widths of the first groove and the second groove are larger than those of the third groove and the fourth groove.

7. The single crystal furnace heating apparatus according to claim 5 or 6, wherein the number of the first U-shaped heating units is smaller than the number of the second U-shaped heating units.

8. The single crystal furnace heating apparatus of claim 5, wherein the plurality of slot sets includes a plurality of first slot sets, a plurality of second slot sets, and a plurality of third slot sets, the plurality of first slot sets, the plurality of second slot sets, and the plurality of third slot sets being spaced apart in a predetermined manner about a central axis of the third heating structure, and the first slot sets include a plurality of first slots, the second slot sets include a plurality of second slots, and the third slot sets include a plurality of third slots, wherein,

the distance from the first end to the second end of the first slot, the distance from the first end to the second end of the second slot, and the distance from the first end to the second end of the third slot decrease in sequence.

9. A single crystal furnace comprising the heating apparatus of any one of claims 1 to 8.

10. A heating method of a single crystal furnace, characterized in that the single crystal furnace comprises the single crystal furnace of claim 9, the heating method comprising:

in the material melting stage, the first heating structure, the second heating structure and the third heating structure are started to work simultaneously, the first heating structure, the second heating structure and the third heating structure are used for heating the molten material in the crucible to melt the molten material to obtain molten liquid, and the power of the first heating structure is greater than that of the second heating structure and the third heating structure in the process;

after the molten material is completely melted into molten liquid, reducing the power of the first heating structure, the second heating structure and the third heating structure to stabilize a thermal field and the molten liquid, wherein the power of the first heating structure is greater than that of the second heating structure and the third heating structure in the process;

and reducing the power of the second heating structure and the third heating structure or closing the second heating structure and the third heating structure, then carrying out fusion welding, shouldering, shoulder rotating and diameter equalizing on the molten liquid to obtain the crystal bar, and in the diameter equalizing stage, the molten liquid in the crucible is in the height range of the first heating structure.

Technical Field

The invention belongs to the technical field of semiconductors, and particularly relates to a heating device of a single crystal furnace, the single crystal furnace and a heating method of the single crystal furnace.

Background

At present, in the preparation process of monocrystalline silicon, a heating device is not separated from the melting of polycrystalline silicon and the normal growth of the monocrystalline silicon, and the heating device is the most important core component in the thermal field structure of the czochralski crystal growing furnace. As the diameter of the crystal bar is continuously increased, the size standard of equipment for growing the crystal bar is larger, and as the size of a thermal field of the straight pulling single crystal furnace is increased, the heating device used by the single crystal furnace is increased. The heating device is mainly used for providing heat for the polycrystalline silicon material in the quartz crucible, melting the initial solid raw material into liquid, ensuring the temperature gradient required by the growth of the monocrystalline silicon, maintaining the normal growth of the monocrystalline silicon and ensuring the crystallization rate of the monocrystalline silicon.

The heating device that uses commonly at present mainly has two kinds, first kind heating device is the heating device who installs in the quartz crucible outside, second kind heating device is including installing the main heater at the quartz crucible lateral part simultaneously and installing the auxiliary heater in the quartz crucible bottom, utilize main heater and auxiliary heater to heat and melt the polycrystalline silicon material, thereby realize the control to the temperature field, wherein, the main heater that is located the quartz crucible lateral part is the graphite heater of drum structure, the main heater includes heating barrel and sets up two at least electrode feet in heating barrel bottom, heating barrel is made by circuitous U style of calligraphy graphite strip end to end connection from top to bottom, vertical banding slot has been seted up on heating barrel along heating barrel's axial direction, the cross-sectional area that is used for reducing resistance, and then increase resistance, thereby make calorific capacity higher. The shape of the auxiliary heater at the bottom of the quartz crucible is various, and the main purpose of the auxiliary heater is to shorten the melting time of the polycrystalline silicon material, improve the production efficiency of the crystal bar and provide a uniform and controllable thermal environment.

However, the temperature distribution of the heating device commonly used at present is not uniform, so that heat convection is generated, the side wall of the crucible is washed, and the quality of the crystal bar is influenced.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a heating device of a single crystal furnace, the single crystal furnace and a heating method of the single crystal furnace. The technical problem to be solved by the invention is realized by the following technical scheme:

a heating device of a single crystal furnace comprises:

the first heating structure is arranged around the crucible, and the heights from the upper end part to the lower end part of the first heating structure are consistent along the circumferential direction;

the second heating structure is arranged around the crucible and positioned below the first heating structure, and a first gap channel is arranged between the upper end part of the second heating structure and the lower end part of the first heating structure;

the third heating structure is positioned below the second heating structure, and the third heating structure is connected with the lower end part of the second heating structure to form a heating cavity;

the heating control mechanism of the first heating structure is different from the heating control mechanisms of the second heating structure and the third heating structure, and the height of the first heating structure meets the condition that the molten liquid in the crucible in the equal-diameter growth stage is within the height range of the first heating structure.

In one embodiment of the invention, the height of the first heating structure is such that a part of the melt in the crucible in the isometric growth stage is within a height range below a radial high temperature line of the first heating structure, and another part of the melt is within a height range above the radial high temperature line of the first heating structure, wherein the radial high temperature line corresponds to a position where the temperature is highest in the axial direction of the first heating structure.

In one embodiment of the invention, the height of the first heating structure is such that the lower half of the melt in the crucible in the isometric growth stage is within a height range below the radial high temperature line of the first heating structure and the upper half is within a height range above the radial high temperature line of the first heating structure.

In one embodiment of the invention, the ratio of the height of the first heating structure to the height of the second heating structure ranges from 1:1 to 2: 1.

In one embodiment of the invention, the first heating structure is provided with a plurality of first U-shaped heating units which are uniformly distributed along the circumferential direction;

a plurality of second U-shaped heating units which are uniformly distributed along the circumferential direction are arranged on the second heating structure;

the third heating structure is provided with a plurality of slot groups which are arranged at intervals around the central axis of the second heating structure, a third gap channel is arranged at the central position of the third heating structure, the slot groups are communicated with the third gap channel, and a plurality of second connecting holes are also formed in the third heating structure;

the lower end part of the first heating structure is further provided with a heater pin, the heater pin is positioned in the side groove of the second heating structure and the bottom groove of the third heating structure, a second gap channel is arranged between the heater pin and the side groove of the second heating structure and the bottom groove of the third heating structure, and the heater pin is further provided with a first connecting hole.

In an embodiment of the present invention, the first U-shaped heating unit is formed by a portion between two adjacent first grooves on the first heating structure, and a second groove is further disposed at a middle position between the two adjacent first grooves, wherein the first groove is a groove extending from a lower end portion to an upper end portion of the first heating structure, and the second groove is a groove extending from the upper end portion to the lower end portion of the first heating structure;

the second U-shaped heating unit is formed by a part between two adjacent third grooves on the second heating structure, and a fourth groove is further arranged in the middle of the two adjacent third grooves, wherein the third groove is a groove extending from the lower end part to the upper end part of the second heating structure, and the fourth groove is a groove extending from the upper end part to the lower end part of the second heating structure;

the length of the first groove is smaller than that of the second groove, the width of the first groove is equal to that of the second groove, the length of the third groove is smaller than that of the fourth groove, the width of the third groove is equal to that of the fourth groove, and the widths of the first groove and the second groove are larger than those of the third groove and the fourth groove.

In one embodiment of the present invention, the number of the first U-shaped heating units is smaller than the number of the second U-shaped heating units.

In one embodiment of the invention, the plurality of slot sets comprises a plurality of first slot sets, a plurality of second slot sets, a plurality of third slot sets, the plurality of first slot sets, the plurality of second slot sets, the plurality of third slot sets being spaced apart in a predetermined manner around a central axis of the third heating structure, and the first slot sets comprise a plurality of first slots, the second slot sets comprise a plurality of second slots, the third slot sets comprise a plurality of third slots, wherein,

the distance from the first end to the second end of the first slot, the distance from the first end to the second end of the second slot, and the distance from the first end to the second end of the third slot decrease in sequence.

An embodiment of the invention also provides a single crystal furnace, which comprises the heating device of the single crystal furnace in any one of the embodiments.

An embodiment of the present invention also provides a heating method of a single crystal furnace including the single crystal furnace according to claim 9, the heating method including:

in the material melting stage, the first heating structure, the second heating structure and the third heating structure are started to work simultaneously, the first heating structure, the second heating structure and the third heating structure are used for heating the molten material in the crucible to melt the molten material to obtain molten liquid, and the power of the first heating structure is greater than that of the second heating structure and the third heating structure in the process;

after the molten material is completely melted into molten liquid, reducing the power of the first heating structure, the second heating structure and the third heating structure to stabilize a thermal field and the molten liquid, wherein the power of the first heating structure is greater than that of the second heating structure and the third heating structure in the process;

and reducing the power of the second heating structure and the third heating structure or closing the second heating structure and the third heating structure, then carrying out fusion welding, shouldering, shoulder rotating and diameter equalizing on the molten liquid to obtain the crystal bar, and in the diameter equalizing stage, the molten liquid in the crucible is in the height range of the first heating structure.

The invention has the beneficial effects that:

according to the invention, the heights of the upper end part of the first heating structure and the lower end part of the first heating structure are consistent along the circumferential direction of the first heating structure, the heat provided by the first heating structure can ensure that the molten liquid is maintained in a molten state in the equal-diameter growth stage, the temperature of the heating area of the first heating structure is stable and uniform, the scouring of thermal convection to the crucible is reduced, enough longitudinal temperature gradient can be provided in the molten liquid and at a solid-liquid interface, the whole equal-diameter process is kept to be stably carried out, the fluctuation of the solid-liquid interface is ensured to be small, and the quality of the crystal bar is ensured.

The present invention will be described in further detail with reference to the accompanying drawings and examples.

Drawings

FIG. 1 is a schematic diagram of a heater provided in the prior art;

FIG. 2 is a schematic structural diagram of a heating device of a single crystal furnace according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a first heating structure according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a second heating structure provided in accordance with an embodiment of the present invention;

FIG. 5 is a schematic diagram of a third heating structure provided in an embodiment of the present invention;

FIG. 6 is a schematic view of a radial high temperature line of a first heating structure provided by an embodiment of the present invention;

FIG. 7 is a schematic structural view of a single crystal furnace provided in the prior art;

FIG. 8 is a schematic structural diagram of a single crystal furnace according to an embodiment of the present invention.

Description of reference numerals:

a first heating structure-10; a second heating structure-11; a third heating structure-12; a first clearance channel-13; a second clearance channel-14; a third interstitial channel-15; a main heater-16; a sub-heater-17; quartz crucible-18; melt-19; graphite crucible-20; graphite bolt-21; a supporting rod-22; a first U-shaped heating unit-101; a lower end-102 of the first heating structure; a heater pin-103; a first connection hole-104; a first trench-105; a second trench-106; an upper end-107 of the first heating structure; center position of the first heating structure-108; a second U-shaped heating unit-111; an upper end-112 of the second heating structure; side grooves-113; a lower end-114 of the second heating structure; a third trench-115; a fourth trench-116; a bottom trench-121; a second connection hole-122; center position-161 of the main heater; a first leg-1031; a second leg-1032; a first slot set-1211; a second slot set-1212; a third slot group-1213; a first slot-12111; a second slot-12121; a third slot-12131; a first end-121111 of the first slot; a second end of the first slot-121112; a first end-121211 of the second slot; a second end-121212 of the second slot; a first end-121311 of the third slot; a second end of the third slot-121312.

Detailed Description

The present invention will be described in further detail with reference to specific examples, but the embodiments of the present invention are not limited thereto.