JP2005225681A5

JP2005225681A5 -

Info

Publication number: JP2005225681A5
Application number: JP2004012415A
Authority: JP
Filing date: 2004-01-20
Publication date: 2007-03-08
Anticipated expiration: 2024-01-20

Description

また、別の方法として、昇華法によりサファイア基板上にＧａＮ種結晶基板を作製する方法の一例について説明する。耐圧チャンバーの中に、坩堝を配置し、この中にＧａＮ原料を充填する。ＧａＮ原料にはＧａＮ粉末などが用いられる。坩堝の上方の結晶生成領域には、サファイア基板を配置する。坩堝内のＧａＮ粉末は、原料ヒータにより加熱され、キャリアガスである窒素ガスを用いて、結晶生成領域に供給する。結晶生成領域にある基板の表面には、反応ガスであるアンモニアがフローされ、基板上で反応ガスと原料であるＧａが反応して、基板上にＧａＮ結晶が成長する。耐圧チャンバー内にはＮＨ₃とＮ₂の混合ガスを導入し、５気圧（５×１．０１３×１０⁵Ｐａ）の加圧状態として、ＧａＮシード層を育成する。原料温度1150℃、基板温度を1000℃で形成した。成長レートは、100μｍ／ｈで高速成長であった。30minの成長時間に対して、50μｍの厚膜をサファイア上に短時間で形成することができる。得られたＧａＮ半導体層の結晶性を評価したところ、Ｘ線解析装置を用いたωスキャン測定によって得られたロッキングカーブ半値全幅が、0.2度であった。

As another method, an example of a method for producing a GaN seed crystal substrate on a sapphire substrate by a sublimation method will be described. A crucible is placed in a pressure-resistant chamber, and GaN raw material is filled therein. As the GaN raw material, GaN powder or the like is used. A sapphire substrate is disposed in the crystal generation region above the crucible. The GaN powder in the crucible is heated by a raw material heater and supplied to the crystal generation region using nitrogen gas as a carrier gas. Ammonia, which is a reaction gas, flows on the surface of the substrate in the crystal generation region, and the reaction gas and Ga, which is a raw material, react on the substrate to grow a GaN crystal on the substrate. A mixed gas of NH ₃ and N ₂ is introduced into the pressure resistant chamber, and a GaN seed layer is grown in a pressurized state of 5 atm (5 × 1.013 × 10 ⁵ Pa). The raw material temperature was 1150 ° C and the substrate temperature was 1000 ° C. The growth rate was 100 μm / h, which was high-speed growth. A 50 μm thick film can be formed on sapphire in a short time for a growth time of 30 min. When the crystallinity of the obtained GaN semiconductor layer was evaluated, the full width at half maximum of the rocking curve obtained by ω scan measurement using an X-ray analyzer was 0.2 degree.

Claims

(I) Composition formula Al having a full width at half maximum of a two-crystal X-ray rocking curve of 0.1 degree or more on a substrate _uu Ga _vv In _1-u-v1-u-v Forming a semiconductor layer made of a semiconductor represented by N (where 0 ≦ u ≦ 1, 0 ≦ v ≦ 1);
(Ii) Group III nitridation on the semiconductor layer by bringing the semiconductor layer into contact with a melt containing at least one group III element selected from gallium, aluminum and indium and an alkali metal in an atmosphere containing nitrogen. And III-nitride substrate manufacturing method including a step of growing a physical crystal.

2. The method for producing a group III nitride substrate according to claim 1, wherein in the step (i), the full width at half maximum of the two-crystal method X-ray rocking curve is 0.3 degrees or more.

2. The method for producing a group III nitride substrate according to claim 1, wherein in the step (i), the full width at half maximum of the two-crystal method X-ray rocking curve is 1 degree or more.

In the step (i), the composition formula Al _uu Ga _vv In _1-u-v1-u-v A step of forming a semiconductor layer made of a semiconductor represented by N (where 0 ≦ u ≦ 1, 0 ≦ v ≦ 1) under a constant temperature range of T ± 10 ° C. (where 500 ≦ T ≦ 1100). The manufacturing method of the group III nitride board | substrate as described in any one of Claim 1 to 3.

The step (i) is a step of forming an AlN layer on the substrate by a sputtering method,
In the step (ii), in a nitrogen-containing atmosphere, the semiconductor layer is brought into contact with a melt containing at least one group III element selected from gallium and aluminum and an alkali metal, whereby the composition formula Al _xx Ga _1-x1-x 4. The production of a group III nitride substrate according to claim 1, wherein the group III nitride crystal represented by N (where 0 ≦ x ≦ 1) is grown on the AlN layer. 5. Method.

In the step (i), the raw material of the group III nitride crystal is heated, and the composition formula Al is obtained by sublimation. _uu Ga _vv In _1-u-v1-u-v 4. The production of a group III nitride substrate according to claim 1, which is a step of forming a semiconductor layer made of a semiconductor represented by N (where 0 ≦ u ≦ 1, 0 ≦ v ≦ 1). 5. Method.

The method for producing a group III nitride substrate according to any one of claims 1 to 6, wherein the atmosphere containing nitrogen is a pressurized atmosphere.

The substrate is a GaAs substrate whose surface is a (111) plane, a Si substrate whose surface is a (111) plane, a sapphire substrate whose surface is a (0001) plane, or a SiC substrate whose surface is a (0001) plane The method for producing a group III nitride substrate according to any one of claims 1 to 7.

The method for producing a group III nitride substrate according to any one of claims 1 to 8, wherein the melt further contains an alkaline earth metal.

A group III nitride substrate produced by the production method according to claim 1.

A semiconductor device comprising a substrate and a semiconductor element formed on the substrate,
A semiconductor device, wherein the substrate is a group III nitride substrate according to claim 10.

The semiconductor device according to claim 11, wherein the semiconductor element is a laser diode or a light emitting diode.