Sub-quarter micron metallization using ionized metal plasma (IMP) technology

Ionized metal plasma (IMP) technology has been developed for liners and wetting layer deposition of sub-quarter-micron devices. Numerical modeling showed the unique advantages of IMP source over ECR source and long throw sputtering in enhancing bottom coverage. TiN bottom coverage up to 70% were demonstrated The deposition rate, uniformity, bottom coverage and film stress were optimized by tuning rf and de powers, process pressure and bias power. The TiN film microstructure such as crystal orientation and grain size was controlled by process parameters. An IMP TiNx (x < 1, a sub-stoichiometric TiN) film provided superb wetting layer for low temperature aluminum plug process, and high aspect ratio contact holes were filled by using the IMP TiNx wetting layer. The via resistance was improved by IMP Ti deposition. (C) 1998 Elsevier Science Ltd. All rights reserved.