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

首次采用四极质量分析仪研究了一甲基肼-三甲基镓体系在低压化学气相沉积装置生长室中的有效分解反应。研究发现，在300 ℃左右的低温下，可以有效地生成胺、甲胺、氰和烃等产物，甲胺和胺的生成有利于氮化物晶体的生长，用低压化学汽相淀积装置在（001）GaAs衬底上生长GaN层，三甲基镓在氢中进行了检查。衬底温度从400 ° C变化到700 ° C。X射线衍射显示GaN晶体的c轴取向生长在衬底温度从550 ° C到650 ° C时占主导地位，并且由于立方GaN晶体也显示出非常弱的强度。然而，当使用单甲基肼-三甲基镓源在AlN或GaN缓冲层上生长GaN晶体时，仅生长c轴取向的六方GaN晶体，所述缓冲层在（001）GaAs衬底上在较低温度下生长。

A quadrupole mass analyzer is for the first time used to study effective decomposition reactions of monomethylhydraine-trimethylgallium system in a growth chamber of low pressure chemical vapor deposition apparatus. It is found that the puroducts such as amine, methylamine, cyanogen and hydrocarbons, are effectively formed at a temperature as low as around 300ﾟC.The formation of methylamine and amine is available for growing nitride crystals, although The formation of cyanogen is not available.GaN layrs grown on (001) GaAs substrates by low pressure chemical vapor deposition apparatus using monomethylhydraine-trimethylgallium in a hydrogen are examined. The substrate temperature were changed from 400 to 700ﾟC.X-ray diffractions show the c-axis-oriented growth of GaN crystals were dominant in the substrate temperature from 550 to 650ﾟC,and also show very weak intensities due to cubic GaN crystals. However, the only c-axis-oriented hexagonal GaN crystals are grown when GaN crystals are grown using the monomethylhydrazine-trimethylgallium source on an AlN or GaN buffer layr which is grown at lower temperature on (001) GaAs substrate.