Thermal Conductivity of Ternary and Quaternary III-V Compounds.
Rept. no. 1 (Final), 8 Mar 80-30 Sep 83,
NORTH CAROLINA AGRICULTURAL AND TECHNICAL STATE UNIV GREENSBORO DEPT OF ELECTRICAL ENGINEERING
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This research project was directed at investigating methods of measuring the thermal conductivity of semiconducting alloys of III-V compounds GaAlAs, GaInAs.GaInAsP in a thin layer format. Generally, techniques for measuring the thermal properties of bulk materials are not suited for the thin epitaxial layers which are utilized in active devices. The thermal conductivity is an important design parameter for those devices which must dissipate large amounts of power during operation. The proposed measurement technique utilized a conducting epitaxial alloy layer deposited upon a semi-insulating lattice-matched semiconductor substrate. The thin films were prepared by liquid phase epitaxy or current controlled liquid phase epitaxy. In the initial approach, a filamentary sample with ohmic contacts on the epitaxial layer was fabricated. A constant current was passed through this resistor and the resistance change caused by the Joule heating was monitored. This temperature-related change can, in principle, be related to the thermal properties of the epilayer and substrate. However, because the thermal conductivity of the alloy epilayer is somewhat less than that of the substrate and the epilayersubstrate thickness ratio is quite small, reasonable results could not be obtained.
- Physical Chemistry
- Solid State Physics