Proposal of High-Electron Mobility Transistors With Strained InN Channel

By using a Schrödinger-Poisson equation solver, we calculate band diagrams of potentially record fast III-N high electron mobility transistors (HEMTs), which are based on strained InN channels. Assuming cation polarity, pseudomorphic HEMT devices are proposed with a relaxed InAIN buffer layer having Al mole fraction in the range of 0.10-0.15 and with an InAIN barrier layer. Calculations indicate highly confined electrons in the channel with a density of 1.4-2 × 10¹³ cm^-2 if the 5-10-nm-thick InN channel is separated from the barrier by ≤ 0.8-nm-thick GaN spacer. Alternatively, for a nonpolar structure with an Al mole fraction of 0.3 in the InAIN buffer and for a doping 5 × 10¹⁹ cm^-3 in the InAIN barrier, we calculate the InN channel carrier density of approximately 1.4 × 10¹³ cm^-2. We propose to use high-k dielectrics to insulate the gate from the barrier for both of the transistor structures.