Determination of the Ga content in GaxIn1-xSb for high-speed transferred-electron devices

Fundamental properties of the transferred-electron effect of LPE grown GaxIn1-xSb have been examined. In view of the considerably low threshold field (400-600 V/cm, 0.4 < x < 0.8), with a low-saturation domain velocity (5 times 10^{6} cm/s, 0.55 < x < 0.8), and having a relatively low-impact ionization rate, GaxIn1-xSb may be one of the useful materials for high-speed logic devices. An optimum Ga composition for the device is determined to be between 0.7 and 0.8, both from the impact ionization in the high-field domain and the temperature dependence of the current peak-to-valley ratios. A power-delay product of 20 fJ, which is about 1/50 of that of GaAs Gunn logic, is expected in the Gunn-mode operation of the gigabit rate.