Review of selective tungsten and other conductors on structured surfaces

Dramatic advances in selective and non-selective low pressure CVD deposition techniques have been reported in recent months. Particularly in the selective deposition of refractory metals and metal silicides, several important new developments have stimulated strong interest within the microelectronics community. Fundamental studies have revealed importance of byproducts on deposition rate and on the degree of selectivity, while new reactor approaches have led to results that appear to meet manufacturability requirements for advanced ULSI designs. New process gas mixtures have been used to achieve deposition rates near 1 um/min. for selective tungsten films. Reliable refractory metal gate technology and multi-active-level devices have been demonstrated using CVD tungsten and/or molybdenum and tungsten silicide. In this paper a survey of thee results and a perspective on the current status of chemical vapor deposition of metals for VLSI applications is presented