Single Crystalline SOI Square Islands Fabricated by Laser Recrystallization Using a Surrounding Antireflection Cap and Successive Self-Aligned Isolation Utilizing the Same Cap

ABSTRACTA new laser recrystallizing technique has been developedfor high density SOI-LSI's. This technique produces single crystalline silicon islands on an amorphous insulating layerwithout seed. Square windows are opened at arbitrary places in an antireflection cap over a polycrystalline film on an amorphous insulatinq layer. Grain boundaries of the polycrystalline Si in the window are removed completely at the subsequent laser-recrystallization step. Single crystalline silicon islands are formed by self-aligned etching of silicon film which was covered by the antireflection cap. This technique is an effective method for fabricating high density SOI-LSI's, since the singlecrystalline islands can be fabricated at arbitrarily selected places. Yield of the grain-boundary-free islands was 95% the size of the island is 1O x 20μm, and the irradiation oyerlap of laser-beam traces is 70%.