Morphology and chemical termination of HF-etched Si{sub 3}N{sub 4} surfaces
- Components Research, Intel Corporation, Hillsboro, Oregon 97124 (United States)
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.
- OSTI ID:
- 22395605
- Journal Information:
- Applied Physics Letters, Vol. 105, Issue 26; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
Similar Records
Fluorocarbon based atomic layer etching of Si{sub 3}N{sub 4} and etching selectivity of SiO{sub 2} over Si{sub 3}N{sub 4}
Selective etching of high-k HfO{sub 2} films over Si in hydrogen-added fluorocarbon (CF{sub 4}/Ar/H{sub 2} and C{sub 4}F{sub 8}/Ar/H{sub 2}) plasmas