Contributionxc of carbon to growth of strained silicon, dopant activation and diffusion in silicon

Abstract

C incorporation into Si and SiGe has become essential in modern high-performance CMOSFET technology. The reason is that C atom is markedly useful in growing strained Si film and controlling diffusion of dopant atoms in Si and SiGe layers. In this paper, contribution of C atoms to the growth of strained Si and SiGe films, the activation and the diffusion of B in Si are described. Interstitial C atoms inhibit an epitaxial growth of strained Si:C and SiGe films in both case for the C implantation followed by annealing and for the epitaxial growth of SiGe:C by RP-CVD. Suppressions of the localized change in strain caused by C incorporation and the localized C atoms successfully achieve a high-crystallinity strained Si:C and SiGe:C films with a high substitutional concentration. A B activation ratio in Si varies depending on incorporated C concentration in the wide range of C and B concentration. Furthermore, C atoms enhance the growth of stable B-containing clusters at a high B concentration region in Si, resulting in decrease in the B activation ratio in Si layer.