Formation of epitaxial NiSi2 of single orientation on (111) Si inside miniature size oxide openings

Abstract

Epitaxial NiSi2 of single orientation was grown on (111) Si inside miniature size oxide openings. Striking oxide opening size effects on the growth of NiSi2 epitaxy were observed. The formation temperature of NiSi2 on (111) Si was found to be as low as 550 °C inside oxide openings 1.8 μm or smaller in size. Epitaxial NiSi2 of single orientation which is identical to that of (111) Si substrate was formed inside oxide openings of or smaller than 1.8, 1, and 0.8 μm in size in samples annealed at 550–750, 800, and 850–900 °C, respectively. The results are discussed in terms of the variation in tensile stress exerted by oxide near the silicon surface and small free-energy difference between type A and type B NiSi2 epitaxy inside small size oxide openings.