InP metal-insulator-semiconductor field-effect transistors utilizing an amorphous phosphorus gate insulator

We have fabricated metal-insulator-semiconductor field-effect transistors (MISFET´s) on InP using plasma-deposited amorphous phosphorus as the gate insulator. This material was selected because it provides low interface state densities (∼10¹²cm^-2. eV^-1) at the phosphorus-InP interface. The resulting 10-µm channel length enhancement-mode transistors have a transconductance of 10 mS/mm, channel mobility of 1800 cm²/V . s, and threshold voltage of +0.6 V. Drain current drift, which has been a problem common to all reported InP MISFET´s, is observed. Possible causes for its occurrence are discussed.