Methods of forming multilayer dielectric regions using varied deposition parameters

Abstract

A dielectric region for a device such as a memory cell capacitor is formed by depositing a metal oxide, such as tantalum oxide, on a substrate at a first deposition rate in a first atmosphere maintained within a first temperature range and a first pressure range that produce a first tantalum oxide layer with a desirable step coverage. Metal oxide is subsequently deposited on the first metal oxide layer in a second atmosphere maintained within a second temperature range and a second pressure range that produce a second deposition rate greater than the first deposition rate to form a second tantalum oxide layer on the first tantalum oxide layer. For example, the first atmosphere may be maintained at a temperature in a range from about 350° C. to about 460° C. and a pressure in a range from about 0.01 Torr to about 2.0 Torr during formation of a first tantalum oxide layer, and the second atmosphere may be maintained at a temperature in a range from about 400° C. to about 500° C. and a pressure in a range from about 0.1 Torr to about 10.0 Torr during formation of a second tantalum oxide layer.