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Low temperature organometallic gas introduction system for chemical beam epitaxy under micro gravity conditions

1993; American Institute of Physics; Volume: 11; Issue: 4 Linguagem: Inglês

10.1116/1.578512

1520-8559

M. Zaltsberg, A. Bensaoula, Charles Horton, R. Haacke, A. Freundlich, P. Mahavadi, V. Rossignol,

Catalytic Processes in Materials Science

Chemical beam epitaxy and organometallic beam epitaxy have become important techniques for use in the growth of III–V compound semiconductors and other materials such as the high temperature superconductors. A critical component of this technology is the delivery system for the organometallic precursors. The gas delivery system vacuum integrity, the flow transient characteristics, and flux uniformity and stability, are all important in the growth of high quality material. A low temperature gas cell and a cylinder based on a novel concept for use on the Wake Shield Facility, a platform that will be used for the growth of semiconductors in space was constructed. The cell is capable of working under micro gravity conditions. Triethylgallium is passed through a sintered stainless steel filter placed at the tip of the cell. The entire cell is made of stainless steel and costs much less than a standard quartz cell. The mechanical and electrical specifications of this new gas cell are presented herein. The transient and equilibrium pressure behavior will be described for triethylgallium delivery both with and without hydrogen carrier gas. The electrical (Hall mobility) and optical (photoluminescence) properties of GaAs epilayers grown with this new design will also be presented. All of the data gathered from these tests were compared to data gathered from a standard Riber low temperature gas cell under the same conditions. The two cells were found to be comparable in their performance. The Riber cell in general had the faster response time. The saturation pressures were in the same range for both cells and the saturation pressure was a linear function of flow rate in all cases studied.