Carrier Transport in High-Mobility III-V Quantum-Well Transistors and Performance Impact for High-Speed Low-Power Logic Applications

• Published in: IEEE electron device letters Vol. 29; no. 10; pp. 1094 - 1097
• Main Authors: Dewey, G., Hudait, M.K., Kangho Lee, Pillarisetty, R., Rachmady, W., Radosavljevic, M., Rakshit, T., Chau, R.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.10.2008; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Benchmark testing; Compound structure devices; Current measurement; Density measurement; Effective carrier velocity; Electrical resistance measurement; Electronics; Exact sciences and technology; FETs; Field programmable gate arrays; III-V materials; InGaAs; InSb; Logic devices; MOSFET circuits; Quantum well devices; Quantum wells; R&D; Research & development; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Silicon; Transistors; InGaAs; silicon; Effective carrier velocity; III-V materials; quantum-well devices; InSb; Test bench; Performance evaluation; Quantum well; MOSFET; State of the art; Quantum effect; III-V compound; Quantum electronics; Charge density; Transport process; Field effect transistor; Low voltage; Frequency characteristic; Low-power electronics; High frequency; Effective mass; NMOS technology; Current gain
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2008.2002945

DC and high-frequency device characteristics of In 0.7 Ga 0.3 As and InSb quantum-well field-effect transistors (QWFETs) are measured and benchmarked against state-of- the-art strained silicon (Si) nMOSFET devices, all measured on the same test bench. Saturation current (I on ) gam of 20% is observed in the In 0.7 Ga 0.3 As QWFET over the strained Si nMOSFET at (V g - V t ) = 0.3 V, V ds = 0.5 V, and matched I off , despite higher external resistance and large gate-to-channel thickness. To understand the gain in I on , the effective carrier velocities (v eff ) near the source-end are extracted and it is observed that at constant (V g - V t ) = 0.3 V and V ds = 0.5 V, the v eff of In 0.7 Ga 0.3 As and InSb QWFETs are 4-5times higher than that of strained silicon (Si) nMOSFETs due to the lower effective carrier mass in the QWFETs. The product of v eff and charge density (n s ), which is a measure of "intrinsic" device characteristics, for the QWFETs is 50%-70% higher than strained Si at low-voltage operation despite lower ns in QWFETs. Calibrated simulations of In 0.7 Ga 0.3 As QWFETs with reduced gate-to-channel thickness and external resistance matched to the strained Si nMOSFET suggest that the higher v eff will result in more than 80% I on increase over strained Si nMOSFETs at V ds = 0.5 V, (V g - V t ) = 0.3 V, and matched I off , thus showing promise for future high-speed and low-power logic applications.