Surface oxide films on Aluminum bondpads: Influence on thermosonic wire bonding behavior and hardness

Using indentation testing, wire bond tests and electron microscopy, the inf luence of increased oxide films on Al metallization surfaces on the wire bo nding behavior and hardness was investigated. Oxide film thickness values l arger than about 20 nm obstruct the bond contact and resulted in a poor bon ding quality. The presence of such films causes also a hardness increase wh ich can be detected by current sensitive indentation test methods. Therefor e, an improved indentation testing technique can be applied during the qual ity control of bondpad metallizations prior to wire bonding. (C) 2000 Elsev ier Science Ltd. All rights reserved.