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Title: Surface cleaning for enhanced adhesion to packaging surfaces: Effect of oxygen and ammonia plasma

The effects of direct plasma chemistries on carbon removal from silicon nitride (SiN{sub x}) and oxynitride (SiO{sub x}N{sub y}) surfaces have been studied by in-situ x-ray photoelectron spectroscopy (XPS) and ex-situ contact angle measurements. The data indicate that O{sub 2} and NH{sub 3} capacitively coupled plasmas are effective at removing adventitious carbon from silicon nitride (SiN{sub x}) and Si oxynitride (SiO{sub x}N{sub y}) surfaces. O{sub 2} plasma treatment results in the formation of a silica overlayer. In contrast, the exposure to NH{sub 3} plasma results in negligible additional oxidation of the SiN{sub x} or SiO{sub x}N{sub y} surface. Ex-situ contact angle measurements show that SiN{sub x} and SiO{sub x}N{sub y} surfaces exposed to oxygen plasma are initially more hydrophilic than surfaces exposed to NH{sub 3} plasma, indicating that the O{sub 2} plasma-induced SiO{sub 2} overlayer is highly reactive toward ambient. At longer ambient exposures (≳10 h), however, surfaces treated by either O{sub 2} or NH{sub 3} plasma exhibit similar steady state contact angles, correlated with rapid uptake of adventitious carbon, as determined by XPS. Surface passivation by exposure to molecular hydrogen prior to ambient exposure significantly retards the increase in contact angle upon exposure to ambient. The results suggest amore » practical route to enhancing the time available for effective bonding to surfaces in microelectronics packaging applications.« less
Authors:
; ; ;  [1] ;  [2]
  1. Department of Chemistry, University of North Texas, Denton, Texas 76203 (United States)
  2. Department of Materials Science and Engineering, University of North Texas, Denton, Texas 76203 (United States)
Publication Date:
OSTI Identifier:
22392136
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films; Journal Volume: 33; Journal Issue: 2; Other Information: (c) 2014 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 42 ENGINEERING; ADHESION; AMMONIA; CARBON; LAYERS; MICROELECTRONICS; OXYGEN; PACKAGING; PASSIVATION; PLASMA; SILICA; SILICON NITRIDES; SURFACE CLEANING; SURFACES; X-RAY PHOTOELECTRON SPECTROSCOPY