摘要
本文用4.2MeV ~7Li离子卢瑟福背散射沟道技术研究了Si上外延GaAs膜在MeV Si离子注入及红外瞬态退火后的再生长过程。实验表明,离子注入可使GaAs外延膜内形成一无序网络,当注入剂量低于某一阈值时,850℃,15秒退火后,损伤区可完全再结晶,再结晶后的GaAs层的晶体质量特别在界面区有很大的改善;当剂量超过该阈值时,出现部分再结晶。激光Raman实验也表明,经过处理后的GaAs层Raman谱TO/LO声子的比率比原生长的样品有很大的降低。
4.2MeV^7 Li channeling techniques and laser Raman scattering spectrometry have beenutilized to study the regrowth of MBE-GaAs films on Si substrates by MeV Si^+ implantationand subsequent rapid infrared thermal annealing.Complete regrowth has been obtained whena buried amorphous layer was formed at the GaAs/Si interface and annealed at 85℃ for15s.Crystalline disorder is greatly reduced in the recrystallized layers especially at the interface.When Si^+ implantation dose exceeds a certain critical value, which leads to severe localnonstoichiometry, incomplete regrowth occurs. The results of Raman scattering show that theratio of TO/LO decreases significantly after annealing.
关键词
离子注入
退火
GAAS/SI
晶体
Ion-implantation
Rapid thermal annealing
Rutherfold backscattering/channeling
