ENHANCEMENT-MODE METAL-SEMICONDUCTOR FIELD-EFFECT TRANSISTORS FROM THIN-FILM POLYCRYSTALLINE DIAMOND

Polpcrystalline CVD diamond films with a near surface hydrogenated lay er have been used to form the first normally off enhancement mode MESF ET structures from this material. A room temperature transconductance of 0.14 mS/mm has been measured, the highest Set reported for a transi stor structure made from polycrystalline material, The devices fully t urn off, display saturation and have a low gate leakage current. Al fo rms a near ideal Schottky barrier on this material (SBH similar to 0.9 8 eV, ideality <1.1) and was used as the gate metallization within the MESFET. Optimized forms of these structures would appear to offer a c ommercially viable route to high-performance diamond based electronic circuits.