Si(111)-(7 × 7) Under Silane UHV-LPCVD: A STM Study

In this work, we present a scanning tunneling microscopy (STM) study of the LPCVD (low pressure chemical vapor deposition) growth of Si on Si(111)-(7 × 7) using silane (SiH₄) decomposition. Surface reactivities have been studied at room and high temperature (700 < T < 800 K), and the major chemical mechanisms have been identified at an atomic scale on the basis of room temperature STM images of the reacted surfaces. The study provides a better understanding of nucleation and initial stages of growth. More particularly, we show that the growth kinetics and the final structure of the film are different from what is observed by molecular beam epitaxial (MBE) growth.