Separation between surface adsorption and reaction of NH3 on Si(100) by flash heating

Separation between surface adsorption and reaction in atomic-layer nitridation of Si(100) in an NH3 environment (50-500 Pa) has been investigated by flash heating using an ultraclean low-pressure cold-wail reactor system. The N atom concentration (n(N)) on Si(100) at 400 degrees C initially increases with flash heating by light irradiation of 60J/cm(2) per shot and then tends to saturate at a certain value (similar to 2.7 x 10(15) cm(-2)). It has been observed that in nitridation with hash heating, a Langmuir-type physical adsorption layer is formed on Si(100), similar to thermal nitridation without Bash heating, and reacts at a certain rate. The physically adsorbed NH3 coverage is the same for both cases with and without Bash heating. The flash heating markedly increases the reaction efficiency of physically adsorbed NH3 as well as the saturation value of n(N). The bonding characteristics observed by X-ray photoelectron spectroscopy in the cases with and without Bash heating were almost similar when n(N) was the same.