Methods of forming semiconductor devices having multilayer isolation structures

摘要

A semiconductor device includes a first structure having a recess having a bottom and opposing side surfaces, and a second structure conformally disposed on the bottom and side surfaces of the recess. The second structure includes a multilayer having two layers having a thickness substantially smaller than a width of the recess. Methods of manufacturing a semiconductor device include providing a first structure having a recess in a deposition chamber and flowing first and second reactants over the first structure for a first period at first and second flow rates. Then, the flow rates of the first second reactants to the first structure are substantially reduced for a pause period. The first and second reactants are then flowed over the first structure for a second period at third and fourth flow rates. The deposition and pause steps may be repeated until a multilayer having a desired thickness is formed.