| AVS 61st International Symposium & Exhibition | |
| Thin Film | Thursday Sessions |
| Session TF+PS-ThM |
| Session: | Advanced CVD and Chemical Vapor Infiltration Methods |
| Presenter: | James Provo, J.L. Provo Consulting |
| Correspondent: | Click to Email |
A recent short history of reactive evaporation by Mattox (1) described various methods for producing oxides, nitrides, carbides, and some compound materials using this special process. However, no mention was made producing hydrides using this method. A study was performed in the mid 1970’s at the General Electric Company (GE) Neutron Devices Department (GEND) in Largo, FL, by the author to study preparation of thin film hydrides using reactive evaporation and to determine their unique characteristics and properties.
Films were produced of scandium (Sc), yttrium (Y), titanium (Ti), zirconium (Zr), and the rare earth praseodymium (Pr), neodymium (Nd), gadolinium (Gd), dysprosium (Dy) and erbium( Er) hydrides by hot crucible filament evaporation in atmospheres of deuterium and tritium gas. All metal vacuum systems were used and dedicated for this special processing. Thin film test samples ~ 5,000Å thick were prepared on half-inch diameter molybdenum disk substrates for each occluder material.
Loading characteristics (i.e., gas –to-metal atomic ratios), oxidation characteristics, film structure, and stress properties were determined and showed near maximum gas-to-metal atomic ratios, variable oxidation properties, platelet type film structures and minimum film stress levels as determined by a double resonator technique. Also, stress aging characteristics were determined for some hydride films prepared in a radioactive tritium gas atmosphere.
The timeless data obtained showed gas-to-metal atomic ratios varied from 1.8 to 2.0, surface oxide levels varied from ~ 80Å to over 1,000Å, and initial normalized differential (tensile) stress levels were (1.0 to 4.0) x 108 dyne/cm2 for tritium loaded samples and (1.0 to 2.0) x 109 dyne/cm2 for deuterium loaded samples. Tritium loading, however, had the undesirable characteristic of having to dispose of the internal processing system fixtures, but the method generally produced desirable thin films.
† Formerly, Principal Member of the Technical Staff at Sandia National Laboratories,
Albuquerque, NM (Retired).
(1) Mattox, D.M., “History Corner- A Short History of Reactive Evaporation”, SVC Bulletin, p.50 –
51, Spring 2014.