High-field electron transport and microwave noise in ZnO channels with 2 dimensional electron gas (Conference Presentation)

Abstract

We studied electron transport and microwave noise in Zn-polar BeMgZnO/ZnO and O-polar ZnO/MgZnO heterostructures with 2-dimensional electron gas (2DEG) grown on c-sapphire substrates by molecular beam epitaxy. In a short-pulse (<5 ns) high-field experiment, the electron drift velocity reached 1.2E7 cm/s at an electric field up to 200 kV/cm. Pulsed microwave hot-electron noise temperature measurements near 10 GHz in O- polar channels indicate that the hot electron temperature is controlled by hot LO phonons, which increase electron temperature, whereas the presence of excess noise (over "thermal" hot-electron noise) in the Zn- polar channels suggests some inhomogeneity of BeMgZnO barriers.