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  ×  107, 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  ×  1012 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.