Using the p-type surface-conductive layer of diamond film, enhancement mode and depletion mode MESFETs have been fabricated by changing the metals of the gate electrode. The threshold voltages of MESFETs depend on the electronegativity of the metals. A MESFET with a Cr gate was operated in depletion mode and exhibited a peak transconductance of 12.3 mS mm-1, which is the highest in diamond FETs. This high performance can be obtained by a self-aligned gate fabrication process, which minimizes the spacing between the ohmic contacts and the Schottky contact. By utilizing an E-MESFET for the driver and a D-MESFET for the active load, E/D-type logic circuits such as NOT, NAND and NOR circuits have been fabricated for the first time.
ASJC Scopus subject areas
- 化学 (全般)