EPI-FILM THICKNESS MEASUREMENTS USING EMISSION FOURIER-TRANSFORM INFRARED-SPECTROSCOPY .2. REAL-TIME IN-SITU PROCESS MONITORING AND CONTROL

Real-time in situ applications of the emission Fourier transform infra red (E/FT-IR) technique are reported in this paper, For real-time proc ess monitoring, we found that the real-time growth rate measured by th e E/FT-IR is responsive to variations of process parameter(s) (i.e., t emperature, pressure, and gas composition). For real-time epi-film thi ckness control, two control algorithm were used: 1) first past the pos t (FPP) method; and 2) linear forecasting, A closed-loop precise epi-f ilm thickness end-point control is demonstrated, Additionally, by real -time monitoring of the incubation time and growth rate, we are able t o obtain qualitative information about the effectiveness of the predep osition wafer cleaning process, Thus, plasma cleaning process optimiza tion time is shortened and post-deposition materials characterization cost is reduced, Using the optimized conditions, we have demonstrated the growth of defect free epitaxial silicon films.