Temperature dependence of the ionization coefficients of AlxGa1-xAs

As AlxGa1-xAs alloys are increasingly used for microwave and millimeter wav e power devices and circuits that work under high electric field intensitie s and junction temperatures; understanding the temperature dependence of im pact ionization and related properties in this material system becomes more and more important. Measurements of the multiplication gain and noise of a valanche photodiodes (APDs) provide insight to the avalanche characteristic s of semiconductors. Previously, me have reported the characteristics of Ga As and Al0.2Ga0.8As APD's at room temperature. In this paper, the gain, and noise of a series of homojunction AlxGa1-xAs APD's were investigated over a wide temperature range from 29 degreesC to 125 degreesC, and the temperat ure dependence of their ionization coefficients was extracted.