A STUDY OF NEW SOURCE MATERIAL FOR GROWING InGaN SYSTEM IN LOW PRESSURE ORGANOMETALLIC CHEMICAL VAPOR PHASE DEPOSITION APPARATUS

首次采用四极质谱仪研究了一甲基肼-三甲基镓和一甲基肼-三甲基铟体系在低压化学气相沉积装置生长室中的有效分解反应。发现在300℃左右的低温下，生成胺、甲胺和烃类等产物，随着温度的升高，生成稳定的氰基和一甲基氰基，并生成乙腈、二甲胺、一甲基腙等中间产物。中间产物在650℃以上分解，采用一甲基肼-三甲基镓-三甲基铟低压化学气相沉积法在GaN非晶衬底上连续生长InGaN层。结果表明，在650 ~ 750℃范围内，随着生长温度的升高，InGaN层中的铟含量逐渐降低，这是由于三甲基铟分解形成在衬底上的铟的脱附量增加所致;在650℃下，在三甲基铟含量不变的情况下，生长层中的铟含量随着三甲基镓含量的增加而增加。

A quadrupole mass analyzer is for the first time used to study effective decomposition reactions of monomethylhydrazine-trimethylgallium and monomethylhydrazine-trimethylindium systems in a growth chamber of low-pressure chemical vapor deposition apparatus. It is found that the products such as amine, methylamine and hydrocarbons, are formed at a temperature as low as around 300℃ and that the stable cyane and monomethylcianide are formed together with intermediate products such as acetonitrile, dimethylamine, monomethylhydrazone, etc. as increasing the temperature. The intermediate products are decomposed above a temperature of approximately 650℃ in our apparatus.InGaN layers continuously grown on GaN amorphous layers by a low-pressure chemical vapor phase deposition method using monomethylhydrazine-trimethylgallium-trimethylindium were examined. It is found that the indium content in InGaN layers decreased with the increasing growth temperature from 650 to 750℃ due to the increasing desorption of indium formed on the substrates from the decomposition of trimethylinjium and that the indium content in grown layers increased with increasing the trimethylgallium under the constant trimethylindium at 650℃.