Study On Gas Doping Technology On Sillicon Single Crystal

FZ Si single crystal is the major raw material for Power Electronics device manufacturing, which output is around 6%～8% of total Si wafer market. Higher quality Power Electronics has higher requirement of FZ single crystal including integrity, purity and larger diameter. Single crystal with gas doping has the characters of less crystal lattice damage, higher lifetime of minority carrier, shorter production cycle time, higher doping yield and lower cost. With rapid development of Power Electronics device, FZ Si single crystal business demand increases sharply. To deeply investigate doping technology and implement it, this dissertation will focus on the research of gas doping process.This dissertation focus on single crystal growth experiment based on different process condition including asymmetrical heating field setting, interface temperature grads increasing between solid and liquid, and disturber enhancing. Experimental results show that heating field setting is key factor to influence resistance uniformity of single crystal. Asymmetrical heating field is benefit to symmetrical distribution of dopant in the interface between solid and liquid, which also is efficient approach to reduce RRV of FZ Si single crystal.In additional, on the condition of same doping process, experiment shows that doping result is different with variety of single crystal diameter. Single crystal diameter is larger, RRV of gas doping wafer is worse,there is a direct proportion correlation between crystal diameter and RRV approximately.