SINGLE CRYSTAL SILICON SUBSTRATE PREPARED BY VAPOUR-LIQUID INTERFACE GROWTH SINGLE CRYSTAL SILICON SUBSTRATE PREPARED BY VAPOUR-LIQUID INTERFACE GROWTH

Preparing silicon wafers is a tedious multi-step process that includes etching, polishing, and cleaning. The minimum wafer thickness attainable in current high volume wafer production processes is generally 160 to 300 µm, and the kerf loss for these processes is up to 40 % of the total volume. Thin silicon wafers (~30 to 100µm) are very expensive to produce and the wafering process is not cost effective due to the high amount of material loss (more than 80 % at these dimensions) during the process and the risk of breakage of the wafers during wafering. In this thesis, a new method called Vapour-Liquid Interface Growth (VLIG) is proposed. VLIG is capable of directly growing a sheet of single crystal silicon without wafering with a thickness of about 30 to 50µm. The features of the process are 1) low temperature operation; 2) the resulting silicon sheet is easily detachable and self-supporting; 3) the resulting sheet has uniform thickness and is single crystal. The system operates in a supersaturated growth solution of an indium-silicon melt. A seed line in a substrate facing down is employed. A layer of single crystal silicon grows on the see