Effects of SiOx Capping Layer on Electrical and Microstructural Properties of Ge Epilayer Grown on Si (100) Substrate with PH3 Plasma Immersion Ion Implantation
(Room Exhibit Hall A)
30 Apr 19
2:30 PM
-
4:00 PM
We investigated effects of SiOx capping layer on electrical and microstructural properties of Ge epilayer grown on Si (100) substrate with PH3 plasma immersion ion implantation (PIII). After PIII with an energy of 2 keV, 40 nm-thick SiOx films as a capping layer were deposited using plasma enhanced chemical vapor deposition. For dopant activation, implanted Ge epilayers with and without SiOx capping layers were rapid-thermal-annealed at the temperatures ranging from 500 to 800 °C for 1 min. in N2 ambient. For SiOx-capped and uncapped samples, surface amorphous layers produced by PIII were fully recrystallized after annealing above 600 °C. Moreover, the surface uniformity of implanted Ge epilayer with and without SiOx capping layer was greatly improved after annealing at 600 °C, which could be associated with Ge reflow. The sheet resistance of both samples decreased with increasing activation temperature. However, the sheet resistance of SiOx-capped samples was lower than that of uncapped ones. Based on the secondary ion mass spectrometry results, the dose of uncapped samples rapidly decreased with increasing RTA temperature, while SiOx-capped samples showed insignificant change in dose. This implies that SiOx capping layer was effective in the prevention of P out-diffusion during activation annealing process.