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Title: Morphology and chemical termination of HF-etched Si{sub 3}N{sub 4} surfaces

Several reports on the chemical termination of silicon nitride films after HF etching, an important process in the microelectronics industry, are inconsistent claiming N-H{sub x}, Si-H, or fluorine termination. An investigation combining infrared and x-ray photoelectron spectroscopies with atomic force and scanning electron microscopy imaging reveals that under some processing conditions, salt microcrystals are formed and stabilized on the surface, resulting from products of Si{sub 3}N{sub 4} etching. Rinsing in deionized water immediately after HF etching for at least 30 s avoids such deposition and yields a smooth surface without evidence of Si-H termination. Instead, fluorine and oxygen are found to terminate a sizeable fraction of the surface in the form of Si-F and possibly Si-OH bonds. The relatively unique fluorine termination is remarkably stable in both air and water and could lead to further chemical functionalization pathways.
Authors:
; ; ; ; ; ;  [1] ; ;  [2]
  1. Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States)
  2. Components Research, Intel Corporation, Hillsboro, Oregon 97124 (United States)
Publication Date:
OSTI Identifier:
22395605
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 26; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; AIR; CRYSTALS; DEPOSITION; ETCHING; FILMS; FLUORINE; HYDROFLUORIC ACID; MICROELECTRONICS; MORPHOLOGY; OXYGEN; SCANNING ELECTRON MICROSCOPY; SILICON NITRIDES; SURFACES; WATER; X-RAY PHOTOELECTRON SPECTROSCOPY