A simple self-aligned process for GaAs Schottky diodes passivated by liquid phase chemical enhanced oxidation is demonstrated. In addition to the low, temperature process, the passivated native oxide can further reduce the leakage current and enhance the breakdown voltage as compared to the other methods. With the selective oxidation between photoresistor and GaAs, this fabrication process can be further simplified. The process yield of Schottky diode wafer can be as high as 90.6% for a 3-in. diameter wafer. Besides, better RF performance can also be achieved as compared to those Of Si3N4 passivated devices. (C) 2004 Elsevier Ltd. All rights reserved.