Rapid thermal processing (RTP) abruptly decreases the time required to perform solar cell processes. RTP were used to form emitter of crystalline silicon solar cells. The emitter sheet resistance is studied as a function of time and temperature. The objective of this study is reduction of doping process time with same performance. Emitter difRapid thermal dfusion was carried out by using a spin on doping and a RTP. iffusion was performed in the temperature range of $700{sim}750^{circ}C$ for 1m 30s~15 m. Thermal budgets yielded a $50{Omega}/sq$ emitter using a P509 source. To reduce process time and get high efficiency, rapid thermal diffusion by IR lamp was employed in air atmosphere at $700^{circ}C$ for 15 m.