Influence of SiO 2 cap layers on lateral solid-phase epitaxy of implanted amorphous Si films

Abstract

Characteristics of the lateral solid-phase epitaxial (L-SPE) growth of undoped and P-doped amorphous Si (a-Si) films were investigated, in which the a-Si films were covered with SiO 2 cap layeres with thicknesses from 200 nm to 1.8 μm. The Si films were deposited at room temperature in the amorphous state, or they were deposited at elevated temperatures in the polycrystalline state and subsequently amorphized by Si + ion implantation. It was found that L-SPE growth characteristics of a-Si films, such as the saturation L-SPE growth rate, the random polycrystallization time, and the L-SPE growth length from the seed region, were essentially unchanged even in the samples with the SiO 2 cap layers up to 1.8 μm thick, although the fluctuation of such parameters as the polycrystallization time and the initial delay time of L-SPE growth were relatively large particularly in the room-temperature-deposited a-Si films. It is concluded from these results that the L-SPE growth technique is useful for simultaneous growth of multilayered a-Si films separated by SiO 2 layers, which is important in fabrication of the future highly stacked 3-dimensional integrated circuits.