Technology to Watch and Control Particles in Vacuum Processing Equipment

Abstract

  Test wafers are regularly used for monitoring the daily chamber conditions from the viewpoint of particle contamination in the semiconductor manufacturing equipment. Since the number of particles contaminating on a wafer often varies, the particle management by the sampling inspection only observes the situation at the moment. In situ particle monitor (ISPM) is developed as a technique for real time monitoring the particle. This time, ISPM was installed in the mass production 300 mm plasma etcher at the bypass exhaust line connected with a dry pump. The ISPM count at one cleaning cycle and the correlation with the mass production yield were investigated. The ISPM count takes the decreasing tendency immediately after maintenance. The production yield also has fallen with the repeated etching processes. It is able to monitor the yield decrease by managing the logarithmic index of the ISPM count.