A Comparative Study on Si Activation in GaAs Between Laser Annealing and Rapid Thermal Annealing

This work studies the use of pulsed laser annealing (LA) to realize high n-type dopant activation in GaAs. The results show that the defects induced by ion implantation can be effectively eliminated by pulsed LA. Besides preserving a good crystalline structure, a much higher dopant activation can be achieved by LA compared to the conventional rapid thermal annealing technique. The high levels of dopant activation obtained in the laser-annealed GaAs samples are attributed to the out-diffusion of the Zn dopant atoms (the p-type dopant of the GaAs substrate) as well as the Ga atoms from the substrate. Diodes activated by an appropriate fluence exhibit excellent rectifying characteristics.