Low temperature Si:C co-flow and hybrid process using Si3H8/Cl2

Abstract

In this paper we demonstrate a Si3H8/SiH3CH3/PH3/Cl2 based co-flow process and a “hybrid” co-flow process with interruptions of the deposition. The motivation for the work stems from the desire to improve manufacturability through higher growth rates and higher etch rates commensurate with the drive to lower thermal budgets of integration of Complementary Metal Oxide Semiconductor and memory platforms. For high volume manufacturing, high selective epitaxial growth rates are necessary for enhanced throughput and low cost of ownership. Both high growth rate and low temperatures enable sufficiently high substitutional carbon levels [C]sub in dilute Si:C alloys. The hydride deposition gases Si3H8, SiH3CH3 and PH3 and the etch gas Cl2 were kept separate in the pressurized gas supply lines and injected separately into the reaction chamber thus avoiding premature chemical reactions. The importance and the role of a suitable inert carrier gas are emphasized.