| 초록 |
Thin single crystal Si wafer, also known as kerfless Si wafer, is considered as one of the bottleneck to realize low cost and high efficiency Si solar cells. Here, we present new processes to fabricate fabricate thin single crystal Si wafers. Firstly, we present a spalling process to fabricate single crystal Si foils with controlled thickness of 7 – 50 µm. In spalling, a stressor layer atop Si wafers initiates a crack beneath the Si wafer and a thin Si foil is exfoliated by the crack that runs in parallel to the surface of the Si wafer. Secondly, we also present a new process called empty-space in Si (ESS) to fabricate a sub 500 nm thick Si membranes. In ESS technology, ultra-thin Si membrane is formed by morphological evolution of vertically aligned nanoporous Si upon high temperature annealing. Details of various thin Si formation technologies will be presented. |
