Reduce Particles On Vertical LPCVD For Silicane-Nitride Process

Since1990s, Vertical LPCVD system became the necessaryequipment in semiconductor manufacturing industry. It can provide betteruniformity and stage coverage when depositing film, such as silicon nitride,poly-silicon, and silicon dioxide. It also has large capacity of productionwith batch system. Because of using DCS as gas source and large stress ofSilicon-Nitride film, LPCVD Silicon-Nitride process has worse particleperformance.This paper is base on the research of TEL Alpha-8SE LPCVD system.From hardware and process aspect, find out the root cause of the worseparticle performance of silicon nitride process. They are the peeling of tubeand the gas line of DCS. Correspondingly, this paper provide solution forthem: reduce surface roughness of quartz inner tube by modifying cleanfunction, and use low temperature N2purge. These solutions have providedthe ability of reducing particle, prolong PM cycle and improve tool uptime.