Beschreibung:
<jats:title>Abstract</jats:title><jats:p>Electron tunneling from phosphorus atoms into the silicon conduction band is investigated at cryogenic temperatures in metal—insulator—semiconductor (MIS) structures. To observe field ionization and, at the same time, to exclude other competing processes, such as the impact ionization and the electric‐field‐assisted thermal ionization, the experiments are performed with electrical pulses of several ns duration. Field ionization dynamics after the application of a voltage step, when the tunneling time is comparable to the electron transit time through the structure, is analysed theoretically and compared with the experiment. Since the tunneling time is very sensitive to the parameters associated with the impurity it is argued that field ionization experiments may appear valuable in the investigations of shallow impurity states in semiconductors.</jats:p>