Temperature dependence of the ionization coefficients of Al/sub x/Ga/sub 1-x/As

As Al/sub x/Ga/sub 1-x/As alloys are increasingly used for microwave and millimeter wave power devices and circuits that work under high electric field intensities and junction temperatures; understanding the temperature dependence of impact ionization and related properties in this material system becomes more and more important. Measurements of the multiplication gain and noise of avalanche photodiodes (APDs) provide insight to the avalanche characteristics of semiconductors. Previously, we have reported the characteristics of GaAs and Al/sub 0.2/Ga/sub 0.8/As APD's at room temperature. In this paper, the gain and noise of a series of homojunction Al/sub x/Ga/sub 1-x/As APD's were investigated over a wide temperature range from 29/spl deg/C to 125/spl deg/C, and the temperature dependence of their ionization coefficients was extracted.