LPCVD Titanium Nitride for ULSIs

Publisher Website
Google Scholar
Abstract
Characteristics of films formed by low‐pressure chemical vapor deposition (LPCVD) are investigated for application to the barrier layers in ultra‐large‐scale integration (ULSI) which have fine, high‐aspect‐ratio contact holes. The evaluation focuses on the characteristics crucial for barrier layer usage, such as step coverage, N/Ti atomic concentration ratio,, in , and Cl content. Film resistivities are also measured. Excellent step coverage is confirmed. A high‐aspect‐ratio hole, such as one with a diameter of 0.5 μm and a depth of 0.8 μm, is completely filled by film. The atomic concentration ratio for films formed at 500°–650°C is nearly equal to 1. Reduction in the Cl content coming from the source material,, is a matter of concern. High‐temperature deposition is very effective in reducing Cl content. A film deposited at 700°C contains <1 atom percent (a/o) of Cl, much less than films formed at lower temperatures contain. High‐temperature annealing after deposition can also reduce Cl content. The Cl content in a film formed at 500°C is reduced from 5.7 a/o to 2.7 a/o by annealing at 1000°C for 30 min. The resistivity of a film formed at 700°C is 80 μΩ · cm, which is lower than that of a film formed at lower temperatures. This reduction may be due to the decrease in Cl content.

This publication has 0 references indexed in Scilit: