High-temperature operation of polycrystalline diamond field-effect transistors

Operation of polycrystalline diamond field-effect transistors (FETs) at temperatures up to 285 degrees C and drain-to-source voltages of up to 100 V has been demonstrated. The devices were fabricated from B-doped polycrystalline diamond grown by a microwave plasma-enhanced chemical vapor deposition (CVD) technique. At 150 degrees C, the devices exhibited saturation of drain current and a peak transconductance of 65 nS/mm. These are the first polycrystalline diamond devices to demonstrate saturation. Device characteristics at 250 degrees C also show saturation and increased transconductance of 300 nS/mm. Characterization was not performed at temperatures exceeding 285 degrees C due to gate leakage current above 10 nA.< >