Initial Stage of the Interfacial Reaction between Nickel and Hydrogenated Amorphous Silicon

Abstract
The initial stage of the interfacial reaction between Ni and hydrogenated amorphous silicon has been studied mainly by in situ electrical resistance measurement. The change of the resistance in this system induced by the annealing at a constant heating rate shows a sudden drop, which corresponds to the amorphous-to-crystalline transformation of the Ni–Si intermixing layer. In situ resistance measurements for various intermixing layers in the initial stage demonstrate that the crystallization temperature becomes lower with the increase of the amount of Ni contained in the layer. The result means that the thermal stability of the intermixing layer decreases with its growth. It is suggested that the crystallization occurs when the amount of Ni contained in the intermixing layer reaches the critical thickness, which depends on the temperature.