In situ monitoring of Ga(CH3)3 reaction with HCl on nitride semiconductor Metal-Organic Vapor Phase Epitaxy (MOVPE) by using “infiTOF-Pro”
Nitride semiconductors are candidate materials for high-power transistors. To achieve high breakdown voltage performance, the GaN drift layer must be grown with the lowest amount of impurities possible. To improve device performance, several researchers have focused on reducing the carbon, silicon, and oxygen impurities in GaN. Reducing the carbon concentration is especially difficult under conventional growth conditions, because using trimethyl gallium (TMG), which provides a methyl group needed in the production process, also results in carbon impurities. Metal-organic halide-vapor phase epitaxy (MOHVPE) can effectively reduce carbon incorporation by replacing the carbon-based methyl groups with chlorine using HCl. Previous reports on GaN growth by MOHVPE have focused on high growth rate of the GaN bulk crystal without considering the effects of impurity incorporation. However, Amano et al. reported on the impurity concentration in GaN grown by MOHVPE and concluded that chlorine replacement cannot sufficiently reduce the carbon concentration and that the direct reactions must be monitored in the vapor phase.
In this application note, we present the in-situ monitoring of the reaction of TMG with HCl in a conventional horizontal MOVPE reactor using “infiTOF-Pro”.
ガソリン車に代わる有力な候補の一つとして燃料電池車（FCV）が注目を集めています。FCVは水素と酸素を化学反応させて生み出される電力によってモーターを駆動します。FCVの燃料となるFCV用水素燃料の仕様は、ISO（International Organization for Standardization／国際標準化機構）規格において、水素純度規定および不純物濃度規定が定められています（ISO-14687-2）。