A high speed PE-ALD ZnO Schottky diode rectifier with low interface-state density

Zinc oxide (ZnO) has recently attracted attention for its potential application to high speed electronics. In this work, a high speed Schottky diode rectifier was fabricated based on a ZnO thin film deposited by plasma-enhanced atomic layer deposition and a PtOx Schottky contact deposited by reactive radio-frequency sputtering. The rectifier shows an ideality factor of 1.31, an effective barrier height of 0.79 eV, a rectification ratio of 1.17 x 10(7), and cut-off frequency as high as 550 MHz. Low frequency noise measurements reveal that the rectifier has a low interface-state density of 5.13 x 10(12) cm(-2) eV(-1), and the noise is dominated by the mechanism of a random walk of electrons at the PtOx/ZnO interface. The work shows that the rectifier can be used for both noise sensitive and high frequency electronics applications.