Ion Milling Technique to Remove Conductive Haze
Original Publication Date: 1985-Aug-01
Included in the Prior Art Database: 2005-Feb-19
A conductive haze, or thin (<_100-Angstrom) film of iron, has been found on the quartz layer between terminal pads on integrated circuit devices. The haze is believed to be formed when the terminal metal mask loses contact with a wafer during sputter cleaning, causing iron from the sputtering tool and dome to be deposited between the mask and the wafer. The conductive haze decreases device yields and reliability by causing short circuits between adjacent terminal pads. The present technique effectively removes this conductive haze by ion milling the wafer for about 1-2 minutes in an argon plasma. This process also removes other contamination and patchy hazes which may not have been detected during visual examination of the wafer.