Herein we describe theoretical and experimental analysis of the source resistance (Rs) components in In0.7Ga0.3As/In0.52Al0.48As quantum-well (QW) high-electron-mobility transistors (HEMTs) on an InP substrate. First, we analytically modeled Rs using a three-layer formula, separately modeling the regions of the ohmic contact, the gate-to-source access, and the side-recessed regions. The resistances of the ohmic contact and access regions were analyzed in a distributed-network manner with two different transfer lengths, whereas the resistance associated with the side-recess region near the gate edge was modeled by using a lumped element. To verify the accuracy of the proposed Rs model, we fabricated two different types of transmission-line-method (TLM) test patterns as well as long-channel In0.7Ga0.3As/In0.52Al0.48As QW HEMTs, and compared their measured and modeled Rs. The modeled Rs was in excellent agreement with the measured Rs from the recessed TLM patterns and the long-channel HEMTs. Since the widths of the ohmic contact to the heavily doped In0.53Ga0.47As capping layer and the gate-to-source access region were typically much greater than corresponding transfer lengths (LT_cap and LT_barrier), those distributed networks could be simplified to a lumped-element based one-layer model, revealing that the tunneling resistance (Rbarrier) through the In0.52Al0.48As barrier should be carefully considered to minimize the Rs of InxGa1−xAs QW HEMTs together with S/D contact resistances and LGS.
Bibliographical noteFunding Information:
This work was supported by the Technology Innovation Program (20010879, The technology development of device, process and circuit based on InP for ultra low noise amplifier MMIC) funded By the Ministry of Trade, Industry & Energy (MOTIE, Korea) and by the BK21 Plus project funded by the Ministry of Education, Korea (21A20131600011).
© 2021, The Korean Physical Society.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)