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Full-Text Articles in Electronic Devices and Semiconductor Manufacturing
Very-Low-Specific-Resistance Pd/Ag/Au/Ti/Au Alloyed Ohmic Contact To P Gan For High-Current Devices, V. Adivarahan, A. Lunev, M. Asif Khan, J. Yang, Grigory Simin, M. S. Shur, R. Gaska
Very-Low-Specific-Resistance Pd/Ag/Au/Ti/Au Alloyed Ohmic Contact To P Gan For High-Current Devices, V. Adivarahan, A. Lunev, M. Asif Khan, J. Yang, Grigory Simin, M. S. Shur, R. Gaska
Grigory Simin
We report on Pd/Ag/Au/Ti/Au alloyed metallic contact to pGaN. An 800 °C anneal for 1 min in flowing nitrogen ambient produces an excellent ohmic contact with a specific contact resistivity close to 1×10−6 Ω cm2 and with good stability under high current operation conditions. This high-temperature anneal forms an alloy between Ag,Au, and pGaN resulting in a highly p-doped region at the interface. Using x-ray photoelectron spectroscopy and x-ray diffractionanalysis, we confirm that the contact formation mechanism is the metal intermixing and alloying with the semiconductor.
Algan/Gan Metal-Oxide-Semiconductor Heterostructure Field-Effect Transistors On Sic Substrates, M. Asif Khan, X. Hu, A. Tarakji, Grigory Simin, J. Yang, R. Gaska, M. S. Shur
Algan/Gan Metal-Oxide-Semiconductor Heterostructure Field-Effect Transistors On Sic Substrates, M. Asif Khan, X. Hu, A. Tarakji, Grigory Simin, J. Yang, R. Gaska, M. S. Shur
Grigory Simin
We report on AlGaN/GaN metal–oxide–semiconductor heterostructurefield-effect transistors (MOS-HFETs) grown over insulating 4H–SiC substrates. We demonstrate that the dc and microwave performance of the MOS-HFETs is superior to that of conventional AlGaN/GaN HFETs, which points to the high quality of SiO2/AlGaNheterointerface. The MOS-HFETs could operate at positive gate biases as high as +10 V that doubles the channel current as compared to conventional AlGaN/GaN HFETs of a similar design. The gate leakage current was more than six orders of magnitude smaller than that for the conventional AlGaN/GaN HFETs. The MOS-HFETs exhibited stable operation at elevated temperatures up to 300 °Cwith excellent …
Mechanism Of Radio-Frequency Current Collapse In Gan-Algan Field-Effect Transistors, A. Tarakji, Grigory Simin, N. Ilinskaya, X. Hu, A. Kumar, A. Koudymov, J. Yang, M. Asif Khan, M. S. Shur, R. Gaska
Mechanism Of Radio-Frequency Current Collapse In Gan-Algan Field-Effect Transistors, A. Tarakji, Grigory Simin, N. Ilinskaya, X. Hu, A. Kumar, A. Koudymov, J. Yang, M. Asif Khan, M. S. Shur, R. Gaska
Grigory Simin
The mechanism of radio-frequency current collapse in GaN–AlGaN heterojunctionfield-effect transistors(HFETs) was investigated using a comparative study of HFET and metal–oxide–semiconductor HFET current–voltage (I–V) and transfer characteristics under dc and short-pulsed voltage biasing. Significant current collapse occurs when the gate voltage is pulsed, whereas under drain pulsing the I–V curves are close to those in steady-state conditions. Contrary to previous reports, we conclude that the transverse electric field across the wide-band-gap barrier layer separating the gate and the channel rather than the gate or surface leakage currents or high-field effects in the gate–drain spacing is responsible for the current collapse. We …
Research Highlights, Grigory Simin