Device and method for preparing high-purity single crystal germanium by Czochralski method

A single crystal germanium and pulling method, which is applied in the direction of self-melt pulling method, single crystal growth, single crystal growth, etc., can solve the problems of pulling off the crystal rod from the liquid level, uncontrolled crystal pulling, dislocation, etc. Achieve the effect of avoiding crystal cracking, good crystallization performance, and speeding up the rate of chemical material

Pending Publication Date: 2020-04-28
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to the limitation of objective factors such as thermal field and thermal conductivity of germanium single crystal rod, too fast pulling speed will lead to defects such as dislocations and bubbles, and even cause crystal pulling to be out of control or the crystal rod to be pulled out of the liquid surface

Method used

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  • Device and method for preparing high-purity single crystal germanium by Czochralski method
  • Device and method for preparing high-purity single crystal germanium by Czochralski method
  • Device and method for preparing high-purity single crystal germanium by Czochralski method

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preparation example Construction

[0055] A method for preparing high-purity single-crystal germanium according to a specific embodiment of the present invention uses 7N high-purity germanium as a seed crystal and 5N germanium obtained by zone melting as a raw material, comprising the following steps:

[0056] S1: Vacuumize, first place 5N germanium raw material in the crucible 5, vacuumize the crucible 5 for 1-2 times, fill the nitrogen gas from the intake pipe 21 at 1-6L / min, the purity of the nitrogen gas introduced is greater than 5N, and the tail gas Collect and process at the air outlet pipe 22;

[0057] S2: In the chemical material stage, gradually increase the power heating of the heating device 18 high-frequency eddy current induction coil in the early stage, and at the same time turn on the auxiliary heating device 16 to heat the raw material to the first temperature, and keep the power at a stable power in the middle stage. After heating for 30-60 minutes, the later stage The chemical power is reduce...

Embodiment 1

[0066] use figure 1 The device, the angle between the upper heater 19 and the lower heater 20 is 120 °. Both the upper heater 19 and the lower heater 20 are composed of three heating coils connected in series, and the power of a single heating coil is 10-30KW.

[0067] The raw material used is 5N germanium after zone smelting, and the product impurity content, ppm, is as follows:

[0068] Impurities Mg Al Ca Fe co Ni Cu Zn In Pb content <0.05

<0.05

<0.1

<0.05

<0.02

<0.02

<0.01

<0.05

<0.01

<0.02

[0069] (1) Put 5 kg of 5N zone molten germanium raw material in the crucible 5, and place it in the single crystal pulling furnace 1; vacuumize the crucible 5 twice with vacuum equipment, and then fill it with nitrogen gas at 4 L / min to keep the low pressure condition;

[0070] (2) Chemical material stage: In the early stage, gradually increase the power heating of the high-frequency eddy current induction coil unt...

Embodiment 2

[0081] use figure 1 The device, the angle between the upper heater 19 and the lower heater 20 is 120 °. Both the upper heater 19 and the lower heater 20 are composed of three heating coils connected in series, and the power of a single heating coil is 10-30KW.

[0082] The raw material used is 5N germanium after zone smelting, and the product impurity content, ppm, is as follows:

[0083] Impurities Mg Al Ca Fe co Ni Cu Zn In Pb content <0.03

<0.05

<0.1

<0.03

<0.02

<0.02

<0.02

<0.05

<0.01

<0.02

[0084] (1) Put 5kg of 5N zone molten germanium raw material in the crucible 5, and place it in the single crystal pulling furnace 1; vacuumize the crucible 5 twice with vacuum equipment, and then fill it with nitrogen at 5L / min to keep the low pressure condition;

[0085] (2) Chemical material stage: In the early stage, gradually increase the power heating of the high-frequency eddy current induction coil until it ...

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Abstract

The invention discloses a device and a method for preparing single crystal germanium by a Czochralski method. The device comprises a germanium single crystal growth furnace, wherein a crucible is arranged in a cavity of the furnace; a heating device is arranged around crucible, wherein the cross section of the heating device in the single crystal pulling direction is of a symmetrical structure like a pair of round brackets, so that the crucible is enclosed by the heating device; the heating device is divided into an upper heater and a lower heater, wherein the included angle between the upperheater and the lower heater is 110-160 degrees, and a plurality of high-frequency eddy current induction coils which are uniformly distributed from top to bottom are arranged in the upper heater andthe lower heater so as to control the axial and radial gradients of a temperature field around a single crystal. The device disclosed by the invention can be used for regulating and controlling the preparation process of single crystal germanium according to production requirements, and has extremely high operation flexibility and automation potential. The prepared crystal is good in crystallization property, free of defects such as cracking, dislocation, bubbles, inclusions and scattering and high in single crystal repetition rate, and a good crystal growth effect is achieved.

Description

technical field [0001] The invention relates to a germanium purification technology, in particular to a device and method for preparing high-purity single-crystal germanium by a pulling method. Background technique [0002] Germanium is an important semiconductor material. Germanium and its compounds are widely used in the fields of electronics, infrared optics, optical fiber communication, and chemical catalysts. They are one of the most important metals in the modern information industry. [0003] At present, the growth methods of germanium single crystal mainly include single crystal pulling method, horizontal Bridgman method and VGF method. The horizontal Bridgman method has the advantages of fast crystal growth and low cost, but because the crystal is D-type, the utilization rate is low, and it is difficult to grow a large-sized germanium single crystal. The crystal diameter of the VGF method is the same as that of the crucible, and theoretically larger single crystals...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C30B29/08C30B15/14C30B15/20C30B15/30
CPCC30B29/08C30B15/14C30B15/20C30B15/30
Inventor 田庆华李俊郭学益李栋许志鹏
Owner CENT SOUTH UNIV
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