Method for producing thin films by low temperature plasma-enhanced

Abstract

A method for depositing a film on a substrate by plasma-enhanced chemical vapor deposition at temperatures substantially lower than conventional thermal CVD temperatures comprises placing a substrate within a reaction chamber and exciting a first gas upstream of the substrate to generate activated radicals of the first gas. The substrate is rotated within the deposition chamber to create a pumping action which draws the gas mixture of first gas radicals to the substrate surface. A second gas is supplied proximate the substrate to mix with the activated radicals of the first gas and the mixture produces a surface reaction at the substrate to deposit a film. The pumping action draws the gas mixture down to the substrate surface in a laminar flow to reduce recirculation and radical recombination such that a sufficient amount of radicals are available at the substrate surface to take part in the surface reaction. Another method utilizes a gas-dispersing showerhead that is biased with RF energy to form an electrode which generates activated radicals and ions in a concentrated plasma close to the substrate surface. The activated plasma gas radicals and ions utilized in the invention contribute energy to the surface reaction such that the film may be deposited at a substantially lower deposition temperature that is necessary for traditional thermal CVD techniques. Furthermore, the activation of these species reduces the temperature needed to complete the surface reaction. The method is particularly useful in depositing titanium-containing films at low temperatures.