Abstract
Abstract Gallium nitride has the advantages of wide bandgap(3.4eV), high critical electric field(3.4MV/cm), great thermal stability, and high electron saturation velocity(2×107cm/s), which makes it to be operated under high temperature and high voltage. However, one issue is the relatively high cost of GaN based materials. In this study, we use GaN-on-Silicon to solve to problem. GaN-on-Silicon can remain the advantages of GaN and reduce the cost. These advantages make gallium nitride devices great for high frequency and high power applications. Such as High electron mobility transistor (Hemts) and Schottky barrier diode(SBDs) are quite popular recently. Therefore, this thesis will present the study of AlGaN/GaN Schottky barrier diode on the silicon substrate, including device design, manufacturing, measurement, and discussion. It will be mainly focused on how to reduce the turn-on voltage of the Schottky barrier diode and also suppress leakage current by layout design. We use titanium metal which has low work function to reduce the turn-on voltage of Schottky barrier diode. Also, nickel with a higher work function is used to suppress leakage current. As ratio of titanium in Ti/Au anode increases, the turn-on voltage will be decreased. However, it will also cause the increase of leakage current. Different ratios of Ti/Au with various layout geometries have been evaluated for low turn-on voltage and 2 suppressed leakage current. The measured results show that the optimized layout and ratio of Ti/Au will reduce the turn-on voltage from about 0.95V to 0.42V. The highest forward current is 0.121 A/mm, but leakage current will be increased to about 10-5A/mm. .