Thin film deposition method for wafer

Abstract

A thin film deposition method consists of placing a wafer or substrate whose surface contains at least two kinds of materials inside a vacuum chamber or vessel, supplying a reactant gas into the vacuum chamber or vessel, the reactant gas containing molecules having a low sticking coefficient relative to at least one of the at least two kinds of materials, and allowing an epitaxial growth to occur on the other kinds of materials contained in the wafer or substrate. The method further includes setting the pressure inside the vacuum chamber or vessel filled with the reactant gas equal to a pressure range in which the mean free path (d) of the reactant gas molecules is longer than the shortest distance (L) between the wafer or substrate placed inside the vacuum chamber or vessel and the vacuum side-exposed wall of the vacuum chamber or vessel, i.e., d>L. The method further includes slopping the introduction of the reactant gas into the vacuum chamber or vessel until the total amount of the reactant gas introduced into the vacuum chamber or vessel reaches its level at which a thin film can be created onto the surface containing the kind of material having the low sticking coefficient relative to the reactant gas, or more specifically, stopping the introduction of the reactant gas until the total amount of the reactant gas molecules striking against the wafer or substrate reaches its level at which a thin film can be created onto the surface containing the kind of material having the low sticking coefficient.