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Preparation method of high-quality semi-insulating silicon carbide single crystal and substrate doped with a small amount of vanadium

A silicon carbide single crystal, semi-insulating technology, applied in chemical instruments and methods, single crystal growth, single crystal growth, etc., can solve problems such as substrate resistivity instability, uncontrollable crystal quality, and a large number of defects

Active Publication Date: 2019-07-05
SICC CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the intrinsic point defect has a high migration rate in the crystal, and at a certain temperature (such as the temperature condition of GaN epitaxial layer preparation), migration, diffusion and annihilation will occur, which will cause the instability of the substrate resistivity, Also affect the stability of device performance
[0005] The vanadium concentration [V] in doped semi-insulating silicon carbide single crystal is usually 1×10 17 ~1×10 18 cm -3 , corresponding to a nitrogen concentration [N] higher than 10 17 cm -3 The high-concentration vanadium doping in the preparation process has high technical barriers, and it is easy to form a large number of defects and uncontrollable shallow energy level impurity concentration in the prepared crystal, resulting in uncontrollable crystal quality
[N] in high-purity semi-insulating silicon carbide single crystal is 10 15 cm -3 order of magnitude, the corresponding point defect concentration is 1×10 15 cm -3 Level and above, the removal of shallow energy level impurities such as nitrogen in the preparation process requires high technical and capital costs

Method used

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  • Preparation method of high-quality semi-insulating silicon carbide single crystal and substrate doped with a small amount of vanadium
  • Preparation method of high-quality semi-insulating silicon carbide single crystal and substrate doped with a small amount of vanadium
  • Preparation method of high-quality semi-insulating silicon carbide single crystal and substrate doped with a small amount of vanadium

Examples

Experimental program
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Effect test

Embodiment 1

[0069] Example 1 Preparation of semi-insulating silicon carbide single crystal—impurity removal by thermal field device

[0070] The thermal field device includes graphite crucible and graphite insulation felt, and the graphite insulation felt and graphite crucible used for preparing silicon carbide single crystal are subjected to high-temperature purification. The high-temperature purification step includes: placing silicon carbide powder in the graphite crucible, the particle size of the powder is controlled at 50-500 μm, and the quantity is controlled at 50%-80% of the volume of the crucible. After the graphite crucible is placed in the graphite insulation felt and packaged in the silicon carbide crystal growth furnace, it is kept at a certain temperature and pressure for a period of time, and the thermal field device is used to remove impurities. The specific treatment temperature, pressure and time of thermal field 1#, thermal field 2#, thermal field 3#, thermal field 4# ...

Embodiment 2

[0074] Example 2 Preparation of semi-insulating silicon carbide single crystal primary product - mixing and growing crystals

[0075] Doping silicon carbide powder with vanadium element to prepare a small amount of vanadium-doped silicon carbide powder, 0.01-1g vanadium element should be placed in every 1kg reaction silicon carbide powder, the concentration of vanadium in silicon carbide powder after reaction Should be within 1 x 10 16 cm -3 ~1×10 17 cm -3 In order to achieve the content range of vanadium element in the subsequent crystal growth process.

[0076] Place a small amount of vanadium-doped silicon carbide powder in graphite crucibles of heat field 1#, heat field 2#, heat field 3#, heat field 4# and heat field 5# after the treatment in Example 1, and package them into long The crystal furnace is used for the crystal growth step. Taking thermal field 1# as an example to illustrate the crystal growth step, the specific crystal growth conditions of the crystal gro...

Embodiment 3

[0079] Example 3 Preparation of semi-insulating silicon carbide single crystal—annealing

[0080] The primary silicon carbide single crystal prepared in Example 2 was further annealed to prepare a semi-insulating silicon carbide single crystal. Take the annealing treatment of the primary silicon carbide single crystal produced by the crystal growth step in thermal field 1# as an example to illustrate the annealing stage. The semi-insulating silicon carbide single crystal preliminary products prepared in the thermal field 1# of Example 2 respectively through the crystal growth steps in Table 2 were annealed to obtain silicon carbide single crystal 1#, silicon carbide single crystal 2#, and silicon carbide single crystal For single crystal 3#, silicon carbide single crystal 4# and silicon carbide single crystal 5#, the specific annealing conditions are shown in Table 2.

[0081] After the growth of the silicon carbide single crystal is completed, the silicon carbide single crys...

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Abstract

The invention discloses preparation methods of high-quality semi-insulating silicon carbide single crystal doped with a small amount of vanadium and a high-quality semi-insulating silicon carbide single crystal substrate doped with a small amount of vanadium, and belongs to the field of semiconductor materials. The preparation method of the semi-insulating silicon carbide single crystal comprisesthe steps: removing impurities of a thermal field device, mixing materials, performing crystal growth and conducting annealing treatment. The preparation method of the semi-insulating silicon carbidesingle crystal has low technical cost and capital cost, and the resistivity of the prepared silicon carbide single crystal depends on residual shallow energy level impurities and a small amount of vanadium element; since lattice positions are occupied by the impurities, the impurities have high thermal stability, it means that the crystal can have highly stable resistivity; and since the silicon carbide single crystal substrate prepared from the silicon carbide single crystal has high resistivity uniformity and low stress, so that the silicon carbide single crystal substrate has excellent surface quality, and the stability and consistency of the substrate quality in the subsequent epitaxial process are ensured.

Description

technical field [0001] The application relates to a method for preparing a high-quality semi-insulating silicon carbide single crystal doped with a small amount of vanadium and a substrate, and belongs to the field of semiconductor materials. Background technique [0002] Semi-insulating silicon carbide (SiC) single crystal substrate has become the preferred semiconductor material for GaN-based high-frequency microwave devices due to its excellent physical properties such as large band gap, high resistivity and thermal conductivity, and strong breakdown field. With the continuous development of 5G technology, the demand for semi-insulating silicon carbide single crystal substrates on the market side continues to expand. More importantly, batch commercial applications have also put forward higher quality requirements for silicon carbide semi-insulating single crystal substrates. high demands. [0003] The semi-insulating silicon carbide single crystal that has been industria...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C30B23/02C30B29/36C30B33/02
CPCC30B23/025C30B29/36C30B33/02
Inventor 高超刘家朋李加林李长进柏文文宗艳民
Owner SICC CO LTD
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