Voltage distributions in X-band n+-n-n+Gunn devices using a SEM

The SEM has been used as a voltage measuring probe to obtain voltage distributions in X-band n⁺-n-n⁺mesa structure Gunn devices. Dynamic distributions are obtained by operating the instrument in the stroboscopic mode. The results show accumulation layers in the oscillating device and the amplifier mode has a high field anode region.