skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Resistivity, grain size, and impurity effects in chemically vapor-deposited tungsten films

Abstract

The room-temperature electrical resistivity, grain size, and impurity content of tungsten films deposited at low pressure on silicon wafers from tungsten hexafluoride and hydrogen reactants were determined. These properties were examined as functions of deposition temperature and film thickness. The resistivity is independent of thickness at a value of approximately 13.5 ..mu cap omega.. cm for films deposited at 300 /sup 0/C. For films deposited at 400 /sup 0/C, the resistivity decreases from 24 to 8.5 ..mu cap omega.. cm as thickness increases from 0.075 to 1 ..mu..m. The resistivity behavior is interpreted in terms of grain-boundary scattering with a zero reflection coefficient for the 300 /sup 0/C films. For the 400 /sup 0/C films, a reflection coefficient that decreases from 0.67 to 0.38 over the above thickness range and a linear dependence of grain size on thickness are utilized. For both deposition temperatures, the grain size exhibits a rapid initial growth to 30 nm followed by growth at a slope of 0.32 with respect to thickness. The rapid initial growth is associated with the rapid, self-limiting tungsten hexafluoride/silicon reaction. The oxygen content of the films tracks the trend of the reflection coefficient in that it increases with increased depositionmore » temperature or decreased film thickness. Evidence suggests that the oxygen is located predominantly at grain boundaries and may be the primary determinant of boundary scattering. Fluorine is found in films at concentrations (0.03--0.05 at. %) similar to those of oxygen but does not vary with thickness and decreases with increased deposition temperature. No evidence is found for surface scattering of carriers suggesting that all are specularly scattered.« less

Authors:
;
Publication Date:
Research Org.:
Anicon, Inc., San Jose, California 95131
OSTI Identifier:
5425911
Resource Type:
Journal Article
Journal Name:
J. Appl. Phys.; (United States)
Additional Journal Information:
Journal Volume: 58:5
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; SILICON; VAPOR DEPOSITED COATINGS; TUNGSTEN; CHEMICAL VAPOR DEPOSITION; ELECTRIC CONDUCTIVITY; GRAIN SIZE; IMPURITIES; CHEMICAL COMPOSITION; HIGH TEMPERATURE; REFLECTIVITY; THICKNESS; TUNGSTEN FLUORIDES; CHEMICAL COATING; COATINGS; CRYSTAL STRUCTURE; DEPOSITION; DIMENSIONS; ELECTRICAL PROPERTIES; ELEMENTS; FLUORIDES; FLUORINE COMPOUNDS; HALIDES; HALOGEN COMPOUNDS; METALS; MICROSTRUCTURE; OPTICAL PROPERTIES; PHYSICAL PROPERTIES; REFRACTORY METAL COMPOUNDS; SEMIMETALS; SIZE; SURFACE COATING; SURFACE PROPERTIES; TRANSITION ELEMENT COMPOUNDS; TRANSITION ELEMENTS; TUNGSTEN COMPOUNDS; 360104* - Metals & Alloys- Physical Properties

Citation Formats

Learn, A J, and Foster, D W. Resistivity, grain size, and impurity effects in chemically vapor-deposited tungsten films. United States: N. p., 1985. Web. doi:10.1063/1.336010.
Learn, A J, & Foster, D W. Resistivity, grain size, and impurity effects in chemically vapor-deposited tungsten films. United States. https://doi.org/10.1063/1.336010
Learn, A J, and Foster, D W. 1985. "Resistivity, grain size, and impurity effects in chemically vapor-deposited tungsten films". United States. https://doi.org/10.1063/1.336010.
@article{osti_5425911,
title = {Resistivity, grain size, and impurity effects in chemically vapor-deposited tungsten films},
author = {Learn, A J and Foster, D W},
abstractNote = {The room-temperature electrical resistivity, grain size, and impurity content of tungsten films deposited at low pressure on silicon wafers from tungsten hexafluoride and hydrogen reactants were determined. These properties were examined as functions of deposition temperature and film thickness. The resistivity is independent of thickness at a value of approximately 13.5 ..mu cap omega.. cm for films deposited at 300 /sup 0/C. For films deposited at 400 /sup 0/C, the resistivity decreases from 24 to 8.5 ..mu cap omega.. cm as thickness increases from 0.075 to 1 ..mu..m. The resistivity behavior is interpreted in terms of grain-boundary scattering with a zero reflection coefficient for the 300 /sup 0/C films. For the 400 /sup 0/C films, a reflection coefficient that decreases from 0.67 to 0.38 over the above thickness range and a linear dependence of grain size on thickness are utilized. For both deposition temperatures, the grain size exhibits a rapid initial growth to 30 nm followed by growth at a slope of 0.32 with respect to thickness. The rapid initial growth is associated with the rapid, self-limiting tungsten hexafluoride/silicon reaction. The oxygen content of the films tracks the trend of the reflection coefficient in that it increases with increased deposition temperature or decreased film thickness. Evidence suggests that the oxygen is located predominantly at grain boundaries and may be the primary determinant of boundary scattering. Fluorine is found in films at concentrations (0.03--0.05 at. %) similar to those of oxygen but does not vary with thickness and decreases with increased deposition temperature. No evidence is found for surface scattering of carriers suggesting that all are specularly scattered.},
doi = {10.1063/1.336010},
url = {https://www.osti.gov/biblio/5425911}, journal = {J. Appl. Phys.; (United States)},
number = ,
volume = 58:5,
place = {United States},
year = {Sun Sep 01 00:00:00 EDT 1985},
month = {Sun Sep 01 00:00:00 EDT 1985}
}