Pt and Zn based ohmic contacts to p-type InP

Interest in InP as a material for electronic and photonic devices such as junction field effect transistors (JFET) and laser diodes has increased rapidly over the last decade. Low resistance, reliable ohmic contacts play an essential role in the performance of these devices. Solar cells and LEDs require contacts to p-type InP, however, the large (~0.8 eV) barrier height for metals on this material makes their formation difficult. This paper presents the fabrication and characteristics of a new Zn based metallisation for ohmic contacts to p-InP, achieving a lowest specific contact resistance of 2×10^-5 Ω cm²