Dual source gas methods for forming integrated circuit capacitor

Abstract

A silicon layer is formed on an integrated circuit substrate using silane and disilane thereby increasing a step coverage for the silicon layer, increasing a deposition rate for the silicon layer, reducing variability of the deposition rate, and reducing local crystallization of the silicon layer. More particularly, the step of forming the silicon layer can include forming a first silicon sublayer on the substrate using a first source gas including silane, and forming a second silicon sublayer on the first silicon sublayer using a second source gas different from the first source gas wherein the second source gas includes disilane. Alternately, the step of forming the silicon layer can include forming the silicon layer on the integrated circuit substrate using a source gas including a mixture of silane and disilane.