Millisecond Rapid Thermal Annealing of Si Wafer Induced by High-Power-Density Thermal Plasma Jet Irradiation and Its Application to Ultrashallow Junction Formation

摘要

We have investigated the generation of high-power-density thermal plasma jet (TPJ) as a heat source for the annealing of a Si wafer surface in a millisecond period and the formation of an ultrashallow junction. The power density of DC arc discharge thermal plasma jet markedly increased from 11.0 to 32.3 kWkm~2 with increasing spacing between an anode and a cathode (ES) from 1.0 to 3.0 mm. The increase in TPJ power density with ES was mainly due to the increase in plasma temperature from about 16000 to 23000 K. By applying this high-power-density TPJ, the Si wafer was heated by more than 700 K within 10 ms. Using this annealing technique, we demonstrated the dopant activation of an arsenic-implanted Si wafer and successfully obtained a low sheet resistance of 262 Ω/sq at an annealing temperature as high as 1207K without a significantly enhanced diffusion of the implantation profile.