No CrossRef data available.
Article contents
Detection of Voids in Tungsten Interconnect Vias Using Laser-Induced Surface Acoustic Waves
Published online by Cambridge University Press: 01 February 2011
Abstract
Test wafers were prepared under different process conditions of barrier and seed film deposition, in order to study the effects on tungsten plug filling. Tungsten fill percentage was measured using laser-induced surface acoustic wave metrology on plug arrays of varying plug diameter and the results were verified by SEM cross-section. The data show that, for via diameters of 0.12 micron or less, the seed deposition process is a critical factor in effective (void free) plug filling. Seed deposition by ALD and low-temperature CVD were found to be far more effective than conventional CVD. Changing the thickness of the TiN barrier layer was found to have minimal effect on the occurrence of voids. For via diameters greater than 0.12 microns, all of the seed processes led to relatively little voiding.
- Type
- Research Article
- Information
- Copyright
- Copyright © Materials Research Society 2003