Thermal and Non-thermal Activation of Si(100) Surface Nitridation

Abstract

There is currently great interest in understanding the surface chemistry and thin film growth mechanisms of technologically important semiconductors. One intriguing finding of many studies in this area is that unusually high temperatures are required for sustained reactivity and film growth. Thus, for example, silicon nitride film growth using the reaction of Si with NH₃ is carried out at temperatures of l000–1300K.^{(1 ,2)} Intuitively one would expect that the presence of surface dangling bonds should give to semiconductor surfaces a free-radical-like reactivity characterized by low activation barriers. The high process temperatures are often undesirable because they can also enhance the rates of unwanted processes such as dopant diffusion. For these reasons non-thermal means of reaction are actively being sought.⁽³⁾ Essential for the success of such efforts is to understand the mechanism of the reaction, particularly the nature of the rate-limiting step.