CN211689294U

CN211689294U - Heat preservation device for bottom of czochralski crystal growing furnace and czochralski crystal growing furnace

Info

Publication number: CN211689294U
Application number: CN201922387139.7U
Authority: CN
Inventors: 王宇; 冯德伸; 于洪国; 雷同光; 李燕; 马英俊; 林泉
Original assignee: BEIJING GUOJING INFRARED OPTICAL TECHNOLOGY CO LTD
Current assignee: BEIJING GUOJING INFRARED OPTICAL TECHNOLOGY CO LTD
Priority date: 2019-12-25
Filing date: 2019-12-25
Publication date: 2020-10-16
Anticipated expiration: 2029-12-25

Abstract

The utility model relates to a heat preservation device for the bottom of a czochralski crystal growing furnace and the czochralski crystal growing furnace. A heat preservation device for the bottom of a Czochralski single crystal furnace comprises: the crucible rod, and the cover is located one or more heated board on the crucible rod, a plurality of heated board intervals set up. The utility model provides a heat preservation device can remove along with the lift of crucible, and the distance that has kept crucible bottom and heat preservation device is stable, the effectual heat preservation effect that strengthens crucible bottom in the single crystal growing furnace reduces temperature gradient's change to practical convenient, the effect is showing, is applicable to some czochralski method growth technology of the higher crystal of temperature gradient requirement for low dislocation germanium etc..

Description

Heat preservation device for bottom of czochralski crystal growing furnace and czochralski crystal growing furnace

Technical Field

The utility model relates to a semiconductor preparation field, in particular to heat preservation device and czochralski crystal growing furnace are used to czochralski crystal growing furnace bottom.

Background

The Czochralski method, abbreviated as the CZ method, was established in 1918 by the Czochralski method. It has become one of the main methods for single crystal growth, and is used for preparing semiconductor materials such as silicon, germanium, indium antimonide, etc., and large crystals of oxides and other insulation types. When the Czochralski method is adopted to grow the low-dislocation single crystal or the semiconductor grade single crystal, the heat field with extremely small temperature gradient is a necessary measure for most crystal growth. The method obtains a small temperature gradient thermal field, and mainly comprises the design of a heater and the design of a thermal field heat preservation device. The main material for system heat preservation is graphite carbon felt, and a layer of thicker graphite carbon felt is wrapped outside a crucible in a single crystal furnace under the general condition, so that a better heat preservation effect can be obtained, but for crystals with harsh requirements on a thermal field, such as low-dislocation germanium single crystals and the like, the heat preservation of the side surface of the crucible is far from insufficient, and the heat preservation of the bottom and the upper part is guaranteed, so that the method is an important measure for obtaining a small-temperature-gradient thermal field suitable for growth. The bottom of a common single crystal furnace is kept warm by adding a solidified carbon felt at the bottom, but the carbon felt cannot move along with the lifting of the crucible, so that the temperature gradient in the lifting process is changed by the change of the distance between the crucible and the solidified carbon felt at the bottom, and the stability of a thermal field is influenced.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a heat preservation device is used to czochralski crystal growing furnace bottom, this heat preservation device can eliminate among the prior art influence that temperature gradient received crucible and the change of bottom solidification carbon felt distance in the crucible lift process.

In order to achieve the above object, the utility model provides a following technical scheme:

a heat preservation device for the bottom of a Czochralski single crystal furnace comprises:

a crucible rod is arranged on the crucible pot,

and one or more insulation boards sleeved on the crucible rod, wherein the insulation boards are arranged at intervals.

The crucible rod in the heat preservation device is generally fixedly connected with the bottom of a crucible in the czochralski single crystal furnace (or the position of the crucible rod and the crucible rod is relatively fixed), so that the crucible is convenient to carry to lift, the distance between all heat preservation plates sleeved on the crucible rod and the crucible is fixed, the change of the heat preservation plates along with the lifting of the crucible is avoided, the fluctuation of the temperature gradient in the lifting process of the crucible is avoided, and the improvement of the growth yield of low dislocation single crystals is ensured.

To sum up, the utility model provides a heat preservation device can remove along with the lift of crucible, has kept crucible bottom and heat preservation device's distance stable, the effectual heat preservation effect that has strengthened crucible bottom in the single crystal growing furnace reduces temperature gradient's change to practical convenient, the effect is showing, is applicable to some czochralski method growth technology to the higher crystal of temperature gradient requirement such as low dislocation germanium.

On the basis, other structures can be improved, and the details are as follows.

Preferably, the heat insulation plate is detachably connected with the crucible rod.

Adopt detachable to connect, both be convenient for overhaul, also be convenient for adapting to quantity or specification etc. of technology adjustment heated board. A ring-shaped heat-insulating plate, i.e. a central opening through which the crucible rod can be passed, or a plurality of small plates which can be spliced into a ring shape, is usually used.

Preferably, a shoulder is arranged on the crucible rod, and the heat insulation plate is placed on the shoulder.

The shoulder means a diameter larger than the diameter of the whole crucible rod, i.e. protruding from the crucible rod. The shoulder may be formed integrally with the crucible shaft or may be formed separately, for example, by fitting a ring-shaped member on the crucible shaft.

Preferably, when the number of the heat preservation plates is multiple, a plurality of shoulders which correspond to the heat preservation plates one by one are arranged on the crucible rod, and the shoulders between the two heat preservation plates are quartz rings sleeved on the crucible rod.

The quartz ring has excellent high temperature resistance and heat preservation effect, and when the heat preservation board is a plurality of, every two heat preservation boards and the quartz ring circular bead between them can constitute the heat preservation chamber, reinforcing the heat preservation effect in thermal field. For this reason, the number of the heat-insulating plates and the quartz rings can be increased according to the process adaptation.

Preferably, the outer diameter of the quartz ring is less than the outer diameter of the heat-insulating plate.

Thus forming an effective insulating chamber.

Preferably, the plurality of insulation boards are arranged at equal intervals.

The equal interval arrangement ensures the uniformity of temperature.

Preferably, the heat insulation plate is an annular graphite plate or an annular graphite felt.

The utility model discloses still protect the above czochralski crystal growing furnace that heat preservation device constitutes for czochralski crystal growing furnace bottom, the czochralski crystal growing furnace includes promptly:

a crucible;

and the heat preservation device for the bottom of the Czochralski single crystal furnace is connected with the bottom of the crucible.

To sum up, compare with prior art, the utility model discloses following technological effect has been reached:

(1) the heat preservation device can move synchronously with the crucible, so that the fluctuation of the temperature gradient in the system is effectively reduced;

(2) two heated boards adopt the quartz ring to separate, and the purpose makes crucible and furnace body bottom form a plurality of heat preservation chambeies, strengthens the heat preservation effect of system more.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings.

FIG. 1 is an overall schematic view of a heat retaining device for the bottom of a Czochralski single crystal furnace;

FIG. 2 is a top view of an insulation board;

FIG. 3 is a side view of an insulation board;

FIG. 4 is a top view of a quartz ring;

FIG. 5 is a side view of a quartz ring;

FIG. 6 is a side view of a crucible rod;

FIG. 7 is a top view of a crucible rod;

FIG. 8 is a schematic view of the heat retaining device assembled in the Czochralski crystal growing furnace.

Reference numerals:

1-heat insulation plate, 2-quartz ring and 3-crucible rod.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to examples, but those skilled in the art will understand that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The heat preservation device for the bottom of the czochralski single crystal furnace comprises a crucible rod 3, two heat preservation plates 1 and a quartz ring 2, wherein the two heat preservation plates 1 and the quartz ring 2 are sleeved on the crucible rod 3, and the bottom of the heat preservation plate 1 at the lowest part is a bulge of the crucible rod 3 so as to clamp the heat preservation plate 1.

The top view and the side view of the insulation board 1 are shown in fig. 2 and 3, respectively.

The quartz ring 2 is shown in top and side views in fig. 4 and 5, respectively.

The crucible rod 3 is shown in fig. 6 and 7 in a side view and a top view, respectively.

As shown in FIG. 8, the device after the heat retaining device is installed in a Czochralski single crystal furnace is characterized in that the top of a crucible rod 3 is installed at the bottom of a crucible.

The dimensions of the structures in the heat preservation device are arbitrary and designed according to the process requirements, and for example, the typical dimensions are as follows:

the external diameter of the heat insulation plate is 409mm, the internal diameter is 73mm, and the thickness is 15 mm; the quartz ring has the inner diameter of 80mm and the outer diameter of 90 mm; the diameter of the two ends of the crucible rod is 72mm, the diameter of the middle bulge part is 90mm, the length of the bulge part is 50mm, the length of the crucible rod at the upper end of the bulge part is 150mm, and the length of the lower end of the crucible rod is 300 mm. The size of each part can the adaptability adjust when practical application, the utility model discloses be not limited to above size.

The heat preservation device that contains two heated boards has only been shown above, but the quantity of heated board can be increased and decreased in the actual product, sets up one, three or more heated boards. The plurality of insulation boards are preferably arranged at equal intervals.

The material of the insulation board is excellent in high insulation, such as a typical graphite plate or graphite felt.

The material of the quartz ring may be replaced by other materials, such as graphite.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention should be covered by the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A heat preservation device for the bottom of a Czochralski single crystal furnace is characterized by comprising:

a crucible rod is arranged on the crucible pot,

the plurality of insulation boards are sleeved on the crucible rod and are arranged at intervals; the heat insulation plate is detachably connected with the crucible rod; the crucible rod is provided with a plurality of shoulders which correspond to the heat-insulating plates one by one, and the shoulders between the two heat-insulating plates are quartz rings sleeved on the crucible rod.

2. The heat insulating device for the bottom of a Czochralski single crystal furnace as claimed in claim 1, wherein an outer diameter of the quartz ring is smaller than an outer diameter of the heat insulating plate.

3. The heat insulating device for the bottom of a Czochralski single crystal furnace according to claim 1 or 2, wherein the plurality of heat insulating plates are arranged at equal intervals.

4. The heat preservation device for the bottom of the Czochralski single crystal furnace according to claim 1 or 2, wherein the heat preservation plate is an annular graphite plate or an annular graphite felt.

5. A Czochralski single crystal growing furnace, comprising:

a crucible;

and the heat insulating device for the Czochralski single crystal furnace bottom part as set forth in any one of claims 1 to 4, which is connected to the bottom part of the crucible.