Noise in short n+-n--n+GaAs diodes

Noise measurements in a short, near-ballistic, n⁺-n^--n⁺GaAs diode are reported. The device had a linear characteristic below 100 mA. It showed1/fnoise at low frequencies and a white noise close to the thermal noise of the device conductancegat high frequencies. The1/fnoise is most likely mobility fluctuation noise; we evaluated Hooge's parameter α and found a value of 1.95 × 10^-6at room temperature and 0.959 × 10^-6at liquid nitrogen temperature. We also observed a1/fnoise spectrum turning over into1/f^0.5spectrum at 77 K.