Influence of growth conditions on morphology, composition, and electrical properties of n-Si wires

Abstract

A relationship between growth conditions of silicon wires and their morphology, composition, and electroconductivity is presented. In these crystals recently a lattice parameter change and a visible light emission have been found being almost the same as those observed in porous silicon. The crystals were grown by a method of gas-phase reaction in a sealed tube. Using electron microscopy, X-ray microprobe analysis, ion mass spectrometry, Auger electron spectrometry, and temperature dependencies of electroconductivity, it is shown that the crystals grown in different parts of the tube have various shapes, compositions, and electroconductivities. The study of the grown crystals allows to draw conclusions on the mechanisms of crystal growth and doping, and to find a method for controlling these processes. Varying the growth conditions, one is able to change (i) shape of crystals (cylindrical or prismatic), (ii) size of crystals in the ranges from 1 μm to a few cm (axial) and from 0.1 to 100 μm (transverse), (iii) specific electroconductivity from a few to 200 Ω−1 cm−1 with various degrees of compensation.