Critical issues of growth optimization for Ga0.5In0.5P/GaAs heterojunction bipolar transistors

This work reports on optimization of MOVPE growth procedures for high-quality, highly uniform (4 inch) and highly reliable Ga0.5In0.5P/GaAs-HBTs in a commercial multiwafer reactor. Appropriately to this application the main focus of research have been improvements in base-layer transport properties and their implications for HBT device characteristics and reliability. Different carbon-doping techniques are compared with regard to GaAs:C material quality and GaInP/GaAs-HBT device performance. Base-doping homogeneity and hydrogen incorporation were further aspects of optimization. The obtained differences in HBT device performance and reliability depending on base-growth conditions confirm the importance of optimization of this particular step in the growth process.