Generation of Dislocations Induced by Chemical Vapor Deposited Si₃N₄Films on Silicon

Abstract

The correlation between the dislocation generation and the stress in the (100) Si substrate surface completely covered with CVD Si3N4 films is investigated in relation to the film deposition and subsequent annealing conditions. The stress in the Si3N4 films deposited at 940°C at the NH3 flow rate of 1000 cc/min, when measured at room temperature, is tensile with 1.2–1.8×1010 dyn/cm2, and straight dislocations along two sets of [011] and [01] directions are formed in the Si surfaces after heat treatments at temperatures above 1050°C. The stress is small when the films are deposited at the small NH3 flow rate and high deposition temperatures. The interfacial stress generating the dislocations is found to be the inherent intrinsic stress produced during the deposition of Si3N4 film. Some characters of generated dislocations are described.