ULSI用CuおよびAl配線・電極膜の密着性評価

概要

論文の詳細を見る
ULSI integration technology needs extremely fine and thin pattern for wring and electrode films. Aluminum film had been used as wiring and electrode films on ULSI, but recently cupper alloy film has been comprehensively examined because of the higher electrical conductivity of cupper film. The copper wiring film is thin and narrow, and in addition chemical and mechanical polishing is an essential process to planarize the cupper surface. Therefore, adhesiveness of the copper wiring film is one of the crucial factors to manufacture next-generation ULSI such as 4Gb-DRAM. In this study, adhesion measurements were carried out for both patterned copper and aluminum films deposited onto silicon substrate. The main results are summarized as follows; 1) Adhesion strength of the copper film is much lower than the aluminum. Although an etching process is inadequate, and so\as a result, the some over-etch is observed on each patterned film, the adhesion of copper wiring film rises to dangerous level from a viewpoint of both productivity and reliability. 2) Adhesion strength is almost constant independently of film thickness. When the electrode film is thin, film delamination and cracking often occurred in the wire bump process. Both delamination and cracking are not due to the poorer adhesion, but a major cause is lower shock absorption associated with lower film thickness.
足利工業大学の論文
2007-03-20