(Invited) Atomically Controlled Processing for Dopant Segregation in CVD Silicon and Germanium Epitaxial Growth

Abstract

High performance Si-based devices require atomically ordered interface of heterostructures and doping profiles as well as strain engineering, which is obtained by the introduction of Ge into Si. In this work, dopant (P and B) segregation during in-situ doping in CVD Si and Ge epitaxial growth is reviewed. The epitaxial growth of in-situ doped Si and Ge films either on Si(100) or on a few nm-thick Si0.5Ge0.5/Si(100) was performed at 550oC and 350oC, respectively. In the case of P doping, the P atoms segregate to the Si and the Ge surfaces and a part of them are incorporated into the grown Si and Ge cap layers. The P segregation during Si growth is larger than that during Ge growth. In the case of B doping, the B atoms scarcely segregate to the grown Si and Ge surface. Based on these experimental results, the in-situ doping processes are explained by the modified Langmuir-type adsorption and reaction scheme.