Buried Layer Tungsten Deposits In Porous Silicon: Metal Penetration Depth and Film Purity Determinants

Abstract

AbstractInfiltration of anodically prepared porous silicon with tungsten hexafluoride gas has been investigated as a function of silicon porosity, source gas pressure and carrier gas type and flow rate. The depth of tungsten metallization in the silicon has been shown to depend most sensitively on the WF, partial pressure, and less on the flow rate and carrier gas type. Penetration depths of 30 pirn have been attained. Structural integrity of the tungsten layer is dependent on the porosity of the starting material and the degree of internal oxidation of the porous silicon surface area.