Focused Lamp Zone Melting Recrystallization of Silicon on Insulating Substrates

Abstract

Zone melting recrystallization (ZMR) of silicon‐on‐insulator (SOI) has been performed by a pair of focused lamps. Distinction from conventional ZMR's is local instantaneous heating with focused beams on front and back surfaces of SOI wafers, instead of keeping the entire wafer uniformly at the high temperature. 0.4 μm thick poly‐Si films over 2 μm thick insulating layer on the Si substrate are recrystallized without an appreciable redistribution of arsenic atoms implanted,, 150 keV through 50 μm thick films on the Si substrate, which suggests that the focused lamp ZMR can be compatible with the three‐dimensional devices. The unseeded Si film recrystallization on grooved quartz wafers is crack‐free, large‐grained with (100) texture across several chips. For seeded samples, the lateral epitaxy takes place completely over the islands of in size without any subgrain boundaries, in which displacement of the island during ZMR can be avoided by connecting the island to each other with narrow bridges. Major remaining problems for SOI are the warpage of Si wafers and the subgrain boundaries.