The incorporation of silicon from SiH4 into GaAs grown using tertiarybutylarsine (t-C4H9AsH2 or TBAs) as the group V source has been investigated. The dependence of silicon incorporation on growth conditions was used to evaluate the role of gas phase and surface chemistry in the doping process. The use of TBAs results in a greater SiH4 doping efficiency and weaker dependence on growth temperature than is typically observed with AsH3. The doping is insensitive to gas residence time with AsH3 and TBAs, indicating that the process is limited by heterogeneous chemistry in both cases. AsH3 addition to layers grown at a constant TBAs/TMGa ratio results in a rapid decrease in Si incorporation. A surface kinetic-limited process is proposed to describe this behaviour. The influence of TBAs on SiH4 doping chemistry was also found to improve the doping uniformity of GaAs films grown in our metalorganic vapor phase epitaxy (MOVPE) reactor.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Inorganic Chemistry
- Materials Chemistry