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Full-Text Articles in Engineering
Iii-Nitride Transistors With Capacitively Coupled Contacts, Grigory Simin, Z.-J. Yang, A. Koudymov, V. Adivarahan, M. Asif Khan
Iii-Nitride Transistors With Capacitively Coupled Contacts, Grigory Simin, Z.-J. Yang, A. Koudymov, V. Adivarahan, M. Asif Khan
Faculty Publications
AlGaN∕GaNheterostructure field-effect transistor design using capacitively coupled contacts (C3HFET) is presented. Insulated-gate [C3 metal-oxide-semiconductor HFET(C3MOSHFET)] has also been realized. The capacitively coupled source, gate, and drain of C3 device do not require annealedOhmic contacts and can be fabricated using gate alignment-free technology. For typical AlGaN∕GaNheterostructures, the equivalent contact resistance of C3 transistors is below 0.6Ωmm. In rf-control applications, the C3HFET and especially the C3MOSHFET have much higher operating rf powers as compared to HFETs.C3 design is instrumental for studying the two-dimensional electron gas transport in other wide band gap …
Real-Space Electron Transfer In Iii-Nitride Metal-Oxide-Semiconductor-Heterojunction Structures, S. Saygi, A. Koudymov, V. Adivarahan, J. Yang, Grigory Simin, M. Asif Khan, J. Deng, R. Gaska, M. S. Shur
Real-Space Electron Transfer In Iii-Nitride Metal-Oxide-Semiconductor-Heterojunction Structures, S. Saygi, A. Koudymov, V. Adivarahan, J. Yang, Grigory Simin, M. Asif Khan, J. Deng, R. Gaska, M. S. Shur
Faculty Publications
The real-space transfer effect in a SiO2∕AlGaN∕GaN metal-oxide-semiconductor heterostructure (MOSH) from the two-dimensional (2D) electron gas at the heterointerface to the oxide-semiconductor interface has been demonstrated and explained. The effect occurs at high positive gate bias and manifests itself as an additional step in the capacitance-voltage (C‐V) characteristic. The real-space transfer effect limits the achievable maximum 2D electron gas density in the device channel. We show that in MOSH structures the maximum electron gas density exceeds up to two times that at the equilibrium (zero bias) condition. Correspondingly, a significant increase in the maximum channel current (up to …
Simulation Of Hot Electron And Quantum Effects In Algan/Gan Heterostructure Field Effect Transistors, N. Braga, R. Mickevicius, R. Gaska, H. Xu, M. S. Shur, M. Asif Khan, Grigory Simin, J. Yang
Simulation Of Hot Electron And Quantum Effects In Algan/Gan Heterostructure Field Effect Transistors, N. Braga, R. Mickevicius, R. Gaska, H. Xu, M. S. Shur, M. Asif Khan, Grigory Simin, J. Yang
Faculty Publications
We report on simulations of electrical characteristics of AlGaN/(InGaN)/GaN heterostructurefield effect transistors with quantum and hot electroneffects taken into account. Polarization charges lead to quantum confinement of electrons in the channel and to the formation of two-dimensional electron gas. The electron quantization leads to the spread of the electronwave function into the barrier and bulk but does not have significant impact on dc electrical characteristics.Hot electrons play an important part in the charge transport by spilling over into the bulk GaN where they are captured by traps. This leads to negative differential conductivity, which is also observed experimentally. The simulation …
Gan-Algan Heterostructure Field-Effect Transistors Over Bulk Gan Substrates, M. Asif Khan, J. W. Yang, W. Knap, E. Frayssinet, X. Hu, Grigory Simin, P. Prystawko, M. Leszczynski, I. Grzegory, S. Porowski, R. Gaska, M. S. Shur, B. Beaumont, M. Teisseire, G. Neu
Gan-Algan Heterostructure Field-Effect Transistors Over Bulk Gan Substrates, M. Asif Khan, J. W. Yang, W. Knap, E. Frayssinet, X. Hu, Grigory Simin, P. Prystawko, M. Leszczynski, I. Grzegory, S. Porowski, R. Gaska, M. S. Shur, B. Beaumont, M. Teisseire, G. Neu
Faculty Publications
We report on AlGaN/GaN heterostructures and heterostructurefield-effect transistors(HFETs) fabricated on high-pressure-grown bulk GaN substrates. The 2delectron gas channel exhibits excellent electronic properties with room-temperature electron Hall mobility as high as μ=1650 cm2/V s combined with a very large electron sheet density ns≈1.4×1013 cm−2.The HFET devices demonstrated better linearity of transconductance and low gate leakage, especially at elevated temperatures. We also present the comparative study of high-current AlGaN/GaN HFETs(nsμ>2×1016 V−1 s−1) grown on bulk GaN, sapphire, and SiC substrates under the same conditions. We demonstrate that in …