Yield of silicon selective epitaxial growth and its role in the production planning and control of three-dimensional semiconductor devices

Abstract

We focus on the yield (Y) and growth rate (G) of silicon selective epitaxial growth (SEG) at 820 to 970/spl deg/C, and pressures between 40 and 150 Torr. Since the yield of silicon SEG is a potential bottleneck in the manufacture of three-dimensional integrated circuits, e.g., 3-D CMOS, basic knowledge of Y and its dependence on operating conditions, substrate surface parameters, and processing time is of key importance. The conditions investigated include deposition temperature, deposition pressure, SEG thickness, processing time, seed window area, distance between seed windows (local seed window density), and feed composition. The yield is found to improve with higher deposition temperatures, higher HCl feed flows, shorter processing times, higher Cl/H feed ratios, and lower Si/Cl feed ratios. The seed window area and distance between seed windows do not appear to affect the yield at the conditions studied. Growth rate uniformity is observed to improve with lower pressure and temperature, longer processing times, lower HCl feed concentrations, higher Si/Cl feed ratios, and lower Cl/H feed ratios. The implications of these observations for production planning and control of such facilities are discussed.