Formation of large highly textured crystalline Si film on SiO2

Abstract

Amorphous silicon (a-Si) films deposited on oxidized silicon wafers were crystallized to a highly textured form using contact printing of rolled and annealed nickel tapes. Crystallization was achieved by first annealing the a-Si film in contact with Ni tape at 600 degreesC for 20 min in a flowing forming gas (90% N-2, 10% H-2) environment, then removing the Ni tape and further annealing the a-Si film in vacuum for 2 h at 600 degreesC. A needle-like morphology of the crystallization front typical of NiSi2 mediated crystallization was observed. All needles, regardless of their points of origin, belonged to the same [111] family of directions except for the presence of twins and/or type A-B formations, leading to formation of nearly single crystalline regions up to; 20 mm in radius that have their crystal axes oriented the same way in all three directions. Furthermore, the orientational relation between Si grains and Ni tape is observed to be Si[110]parallel toNi[001]. (C) 2003 The Electrochemical Society.