<title>Film stress and adhesion characteristics of passivation layers for thermal ink-jet print head</title>

Abstract

Amorphous, hydrogenated silicon carbide (a-SiC:H) deposited by plasma-enhanced-chemical-vapor deposition has been used as the most important film of passivation layers in a thermal ink-jet printhead. When the printhead was thermal- cycled from room temperature to about 400 degree(s)C, the a-SiC:H film is sustained by a variety of thermal and mechanical stresses that are detrimental to it's integrity. Thermal stress changes of a-SiC:H films were varied with different CH4/SiH4 gas ratios. Microstructure investigation was mainly achieved by FTIR technique. Less variation of the Si-H absorption bond causes less thermal stress change. Thin-film adhesion is an important problem in thermal ink- jet printhead between the Ta thin film and a-SiC:H films. A qualitative measure of film adhesion can be made with the scratch tester. The adhesive critical load and Ta coating failure modes on a-SiC:H were acquired to examine the film adhesion on these two investigated films. The adhesion depends on the nature of the interfacial region, which depends on the interactions between the depositing Ta thin film and the surface a-SiC:H films. An increased effective contact area in the interfacial region promotes a good adhesion.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.