Epitaxy of Si1−xCx via ultrahigh-vacuum chemical vapor deposition using Si2H6, Si3H8, or Si4H10 as Si precursors

Abstract

In this study, disilane (Si2H6), trisilane (Si3H8), and tetrasilane (Si4H10) were used as Si precursors for the growth of Si1−xCx epilayers, and the growth properties of the layers were compared. The use of a higher-order silane significantly increased the growth rates of the Si1−xCx epilayers at a processing temperature of 650 °C. In addition, a higher growth rate realized by using a higher-order silane promoted an increase in the substitutional carbon concentration in the Si1−xCx epilayers owing to the additional injection of a C-source gas (SiH3CH3) and the incorporation of C atoms into substitutional sites. The differences in growth properties between Si precursors were explained on the basis of reaction mechanisms.