TED pattern studies of the structure of post-annealed amorphous silicon layers on single crystal silicon

Abstract

Abstract Two types of amorphous Si layers (thickness ∼1000 A) have been prepared by two different methods. Some layers have been produced by ion bombardment with 5 × 1015 50 keV Ar+/cm2 into single crystal Si at room temperature and others formed by evaporation of nominally undoped Si onto single crystal Si at room temperature. After annealing at 900°C for 30 min, the same twinning pattern, including 24 anomalous {111} spots, has been observed by transmission electron diffraction (TED). The structure has been analysed in detail from the diffraction pattern. As the result, the structure of post-annealed amorphous Si layers on crystalline Si is suggested to be composed of multiply twinned particles (MTP) which can be formed by putting secondary twins on the ‘downward-pointing’ {111} faces of primary twins in the hexagonal model of the MTP revealed by Ino (1966).