Novel chemical precursors and novel CVD strategies enabling low temperature epitaxy of Si and Si:C alloys

Abstract

In this paper we will discuss non-traditional chemical precursors for carbon-doped silicon (Si:C) that enable improved manufacturability through higher growth rates and new deposition temperature regimes commensurate with the drive to lower thermal budgets of integration of CMOS and DRAM platforms. Among the silicon precursors to be discussed are dichlorodisilane (Si 2Cl 2H 4), dichlorosilane and Silcore® (Si 3H 8). New carbon precursors disilylmethane ((SiH 3) 2CH 2) and propylene (C 3H 6) are discussed and compared with conventional monomethylsilane (SiH 3CH 3). For high volume manufacturing, high selective epitaxial growth rates are necessary for high throughput and low cost of ownership. Both, high GR and low temperatures enable high substitutional carbon levels [C] sub in dilute Si:C alloys. Advantages and disadvantages of different Chemical Vapor Deposition (CVD) strategies such as a co-flow process, a Cyclic Deposition/ Etch (CDE) process and a “hybrid” process are discussed.