Progress on background signal analysis of bare wafer inspection systems based on light scattering for III/V epitaxial growth monitoring

The purpose of this paper is to elucidate other applications where the low frequency component of background signal (haze) level of a wafer inspection tool can be used to qualitatively analyze different processes. During initial epitaxial development cycles a fast method of qualifying the growth runs is required. While SEM inspections can sub-sample the wafer, a semi-quantitative way of qualifying growth can be immensely helpful in speeding up the process. In this paper we monitor the epitaxial growth of III/V materials by two different methods: 1) strain relaxed buffers (SRB approach); and, 2) selective epitaxial growth (SEG approach) by using the haze.