CN1624864A - Method of preparing LiGaO2/beta-Ga2O3 composite backing material - Google Patents

Abstract

The invention provides LiGaO2/beta--Ga2O3 composite substrate material and its preparation method, including the following processes: put the LiGaO2 and Li2O composite material with blowholes into the platinum alloy crucible; arrange or suspense the double-face or single-face polishing beta--Ga2O3 on the platinum alloy wire, add the crucible cover that is covered with the mixture powder of LiGaO2 and Li2O and thermocouple, airtight the top of the crucible with the platinum alloy cover, put it into the resistance furnace; heat up the resistance furnace to the temperature about 700-1400deg.C, constant temperature 20-100 hours, Li2O diffuses into beta--Ga2O3 crystal strip, get the LiGaO2/beta--Ga2O3 composite substrate material after the temperature lowering. This invention solves the problems of high mismatch degree of alpha-AL2O3 substrate lattice and not easily getting the big size and good quality of LiGaO2 monocrystal substrate. It is suitable for the epitaxial growth of InN-GaN film with good quality.

Description

LiGaO 2/ β-Ga 2O 3The preparation method of compound lining material

Technical field

The present invention relates to a kind of LiGaO ₂/ β-Ga ₂O ₃Compound lining material and preparation method thereof.LiGaO ₂/ β-Ga ₂O ₃Compound lining material is mainly as the epitaxial growth of InN-GaN base blue-light semiconductor.

Background technology

III hi-nitride semiconductor material InN-GaN has excellent characteristic, as the optical transition probability of stable physics and chemical property, high thermal conductance and high electron saturation velocities, direct band gap material a high order of magnitude than indirect band gap, therefore, broad-band gap InN-GaN base semiconductor is demonstrating wide application prospect aspect short-wave long light-emitting diode, laser and ultraviolet detector and the high-temperature electronic device.Because the InN-GaN fusing point is higher, N ₂Saturated vapor pressure is bigger, and InN-GaN body single crystal preparation is very difficult, so InN-GaN generally grows with epitaxy technology on foreign substrate.

White gem crystal (α-Al ₂O ₃), be easy to preparation, low price, and have the good characteristics such as high-temperature stability, α-Al ₂O ₃It is at present the most frequently used InN-GaN epitaxial substrate material (referring to Jpn.J.Appl.Phys., the 36th volume,, the 1568th page in 1997).

Lithium gallium oxide (LiGaO ₂) be the InN-GaN epitaxial substrate material that just came into one's own in recent years, because the lattice mismatch of itself and GaN epitaxial film is quite little, have only 0.2%, this makes it become a kind of quite desirable GaN epitaxial substrate material (referring to U.S. Pat P6218280, KrylioukOlga, Anderson Tim, Chai Bruce, " Method and apparatus for producinggroup-III nitrides ").

Substrate (α-Al formerly ₂O ₃And LiGaO ₂) the remarkable shortcoming that exists is: (1) is with α-Al ₂O ₃Make substrate, α-Al ₂O ₃And the lattice mismatch between the GaN makes the GaN film of preparation have higher dislocation density and a large amount of point defects up to 14%; (2) because LiGaO ₂The non-stoichiometric volatilization at high temperature takes place in melt easily, and crystal growth difficulty is difficult to obtain large scale, high-quality LiGaO ₂Monocrystal, and the process of substrate has caused a large amount of raw-material wastes.

Summary of the invention

The technical problem to be solved in the present invention is to overcome above-mentioned the deficiencies in the prior art, and a kind of LiGaO for growing high-quality InN-GaN thin film epitaxial growth is provided ₂/ β-Ga ₂O ₃Compound lining material and preparation method thereof.

Compound lining material (LiGaO of the present invention ₂/ β-Ga ₂O ₃) the preparation method utilize vapor transport equilibration (Vapor Transport Equilibration, be called for short VTE) technology, in the atmosphere of high temperature, rich lithium, by insertion of lithium, make Li ₂O and β-Ga ₂O ₃Solid phase reaction takes place, and preparation has LiGaO ₂Tectal β-Ga ₂O ₃Compound lining material (LiGaO ₂/ β-Ga ₂O ₃).

LiGaO of the present invention ₂/ β-Ga ₂O ₃The preparation method of compound lining material comprises that the concrete technology flow process is as follows:

＜1〉in platinum crucible, is placed with the LiGaO of band pore ₂And Li ₂The O mixture block;

＜2〉with the β-Ga of twin polishing or single-sided polishing ₂O ₃Wafer places or is suspended from the platinum wire, adds to be coated with LiGaO ₂And Li ₂It is airtight that the crucible cover of O mixed powder and thermocouple, crucible top add the platinum lid, places resistance furnace;

＜3〉this resistance furnace is heated to about 700～1400 ℃, constant temperature 20～100 hours, Li ₂O is diffused into β-Ga ₂O ₃In the wafer, can obtain LiGaO after the cooling ₂/ β-Ga ₂O ₃Compound lining material.

Described LiGaO ₂And Li ₂The scope of choosing of the weight ratio of O mixture block is [LiGaO ₂]/[Li ₂O]=(0～95): (100～5).

Described resistance furnace is available silicon kryptol stone or the replacement of Si-Mo rod stove also.

The present invention and substrate (α-Al formerly ₂O ₃And LiGaO ₂) compare, its advantage is: overcome formerly α-Al ₂O ₃Substrate lattice mismatch degree is big and be difficult to obtain large-size high-quality LiGaO ₂The problems such as single crystalline substrate can be used for growing high-quality InN-GaN thin film epitaxial growth.

Description of drawings

Fig. 1 is a vapor transport equilibration experimental provision schematic diagram.

Embodiment

Used vapor transport equilibration (VTE) technology of the present invention prepares compound lining material LiGaO ₂/ β-Ga ₂O ₃The experimental provision schematic diagram see Fig. 1, in the platinum crucible 1, be placed with the LiGaO with certain proportioning of pore 2 ₂And Li ₂O mixture block 3, material piece 3 tops are platinum wires 4, the β-Ga of twin polishing or single-sided polishing ₂O ₃Wafer 5 places on the platinum wire 4, and platinum sheet 6 and LiGaO are arranged at material piece 3 tops ₂And Li ₂O mixed powder 7 covers, and thermocouple 8 inserts in the powders 7, and crucible 1 top adds platinum and covers 9 airtight.

Vapor transport equilibration (VTE) technology is a kind of mass transport process, so the crucible planted agent guarantees to have enough Li ₂The O supply, secondly, the balance of gas phase is to rely on Li ₂O is continuously from LiAlO ₂And Li ₂Volatilization is kept in the O mixture block, for preventing mixture block Surface L i ₂O exhausts the balance that causes to be destroyed, and should make mixture block have loose structure.To increase Li as far as possible ₂The evaporation surface of O.

β-Ga ₂O ₃Wafer places or is suspended from the airtight platinum crucible, then airtight platinum crucible is put into electric furnace (silicon carbide rod furnace or Si-Mo rod stove), be heated to predetermined equilibrium temperature, the insulation regular hour is carried out the gas-liquid equilibrium diffusion, in order to accelerate diffusion process and structural adjustment process, should choose as far as possible high equilibrium temperature, generally choose 700～1400 ℃.

Vapor transport equilibration of the present invention (VTE) technology prepares compound lining material LiGaO ₂/ β-Ga ₂O ₃The concrete technology flow process as follows:

＜1〉in platinum crucible 1, is placed with the LiGaO of band pore 2 ₂And Li ₂O mixture block 3 is chosen [LiGaO ₂]/[Li ₂O]=(0～95): (100～5) weight ratio.

＜2〉with the β-Ga of twin polishing or single-sided polishing ₂O ₃Wafer places or is suspended from the platinum wire, adds to be coated with LiGaO ₂And Li ₂The crucible cover of O mixed powder 7 and thermocouple 8, crucible top add platinum and cover 9 airtightly, place resistance furnace.

＜3〉be heated to about 700～1400 ℃ constant temperature 20～100 hours, Li ₂O is diffused into β-Ga ₂O ₃In the wafer.Thereby obtained LiGaO ₂/ β-Ga ₂O ₃Compound lining material.

To prepare LiGaO with above-mentioned vapor transport equilibration experimental provision and concrete technological process below ₂/ β-Ga ₂O ₃The specific embodiment of compound lining material.

In φ 100 * 80mm De platinum gold crucible, be placed with the LiGaO with pore₂And Li ₂The O mixture block is chosen [LiGaO ₂]/[Li ₂O]=75: 25 weight ratios.β-Ga with twin polishing or single-sided polishing ₂O ₃Wafer places or is suspended from the platinum wire, adds to be coated with LiGaO ₂And Li ₂It is airtight that the crucible cover of O mixed powder and thermocouple, crucible top add the platinum lid, places resistance furnace.The heating resistor stove is warming up to 1050 ℃, constant temperature 100 hours, Li ₂O is diffused into β-Ga ₂O ₃In the wafer.Thereby obtained LiGaO ₂/ β-Ga ₂O ₃Compound lining material.This compound substrate can be used for growing high-quality InN-GaN thin film epitaxial growth.

Claims (4)

1, a kind of epitaxially grown LiGaO of high quality InV-GaN that is suitable for ₂/ β-Ga ₂O ₃Compound lining material is characterized in that at β-Ga ₂O ₃Monocrystalline is provided with the LiGaO of one deck quadrature phase ₂, consist of LiGaO ₂/ β-Ga ₂O ₃Compound substrate.

2, a kind of LiGaO ₂/ β-Ga ₂O ₃The preparation method of compound lining material is characterized in that comprising following concrete steps:

1. in platinum crucible, be placed with the LiGaO of band pore ₂And Li ₂The O mixture block;

2. with the β-Ga of twin polishing or single-sided polishing ₂O ₃Wafer places or is suspended from the platinum wire, adds to be coated with LiGaO ₂And Li ₂It is airtight that the crucible cover of O mixed powder and thermocouple, crucible top add the platinum lid, places resistance furnace;

3. this resistance furnace is heated to 700～1400 ℃, constant temperature 20～100 hours, Li ₂O is diffused into β-Ga ₂O ₃In the wafer, can obtain LiGaO after the cooling ₂/ β-Ga ₂O ₃Compound lining material.

3, require 1 described LiGaO according to potentiality ₂/ β-Ga ₂O ₃The preparation method of compound lining material is characterized in that described LiGaO ₂And Li ₂The scope of choosing of the weight ratio of O mixture block (3) is [LiGaO ₂]/[Li ₂O]=(0～95): (100～5).

4, LiGaO according to claim 1 and 2 ₂/ β-Ga ₂O ₃The preparation method of compound lining material is characterized in that described resistance furnace also available silicon kryptol stone or the replacement of Si-Mo rod stove.