CHEMICAL-VAPOR-DEPOSITION OF COPPER FROM CU-I HEXAFLUOROACETYLACETONATE TRIMETHYLVINYLSILANE FOR ULTRALARGE SCALE INTEGRATION APPLICATIONS

In this article, the authors report the results of a study aimed at op timizing a manufacturable thermal copper-chemical vapor deposition pro cess, using (tmvs) Cu-1 (hfac) as the source, where tmvs=trimethylviny lsilane and hfac=hexafluoroacetylacetonate, and establishing associate d material and process characteristics and performance. This study emp loyed a two-stage design of experiments approach in conjunction with a ctual deposition runs on unpatterned silicon (Si) and titanium nitride (TiN) surfaces, as well as SEMATECH patterned TiN structures with fea ture sizes as small as 0.30 mu m with aspect ratio 6:1. All samples we re analyzed by Auger electron spectroscopy, Rutherford backscattering, four-point resistivity probe, and cross-section scanning electron mic roscopy. The results of these analyses showed that precursor concentra tion, substrate temperature, and in situ predeposition substrate surfa ce plasma treatment play a key role in achieving good conformality and complete filling at high growth rates in aggressive via and trench st ructures. Based on these findings, an optimum process window was ident ified and employed to demonstrate complete high growth rate (similar t o 2000 Angstrom/min) filling of 0.3 mu m, 6:1 aspect ratio, devices st ructures with pure copper at as-deposited resistivities of 1.8 mu Omeg a cm. (C) 1996 American Vacuum Society.