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This paper describes for the first time, a high-speed and low-power III-V p-channel QWFET using a compressively strained InSb QW structure. The InSb p-channel QW device structure, grown using solid source MBE, demonstrates a high hole mobility of 1,230cm 2 /V-s. The shortest 40nm gate length (L G ) transistors achieve peak transconductance (G m ) of 510μS/μm and cut-off frequency (f T ) of 140GHz at supply voltage of 0.5V. These represent the highest G m and f T ever reported for III-V p-channel FETs. In addition, effective hole velocity of this device has been measured and compared to that of the standard strained Si p-channel MOSFET. IntroductionThe III-V compound semiconductor quantum-well field effect transistor (QWFET) is one of the most promising device candidates for future high-speed, low-power logic applications due to its high electron mobility. Recently, highperformance III-V n-channel QWFETs have been demonstrated [1][2][3][4]. However, for implementation of CMOS logic, there is a significant challenge of identifying high mobility III-V p-channel candidates [5]. In this work, we demonstrate for the first time a high-speed and low-power III-V p-channel QWFET using a compressively strained InSb QW structure, which achieves cut-off frequency (f T ) of 140GHz at transistor gate length (L G ) of 40nm and supply voltage (V CC ) of 0.5V. This represents the highest f T ever reported for III-V p-channel FETs.

The mobility and carrier concentration of a number of InSb-based modulation-doped quantum well heterostructures are examined over a range of temperatures between 4.5 and 300 K. Wide well ͑30 nm͒ and narrow well ͑15 nm͒ structures are measured. The temperature dependent mobilities are considered within a scattering model that incorporates polar optical and acoustic phonon scatterings, interface roughness scattering, and scattering from charged impurities both in the three-dimensional background and within a distributed "quasitwo-dimensional" doping layer. Room temperature mobilities as high as 51 000 cm 2 / V s are reported for heterostructures with a carrier concentration of 5.8ϫ 10 11 cm −2 , while low-temperature mobility ͑below 40 K͒ reaches 248 000 cm 2 / V s for a carrier concentration of 3.9ϫ 10 11 cm −2. A Schrödinger-Poisson model is used to calculate band structures in the material and is shown to accurately predict carrier concentrations over the whole temperature range. Low-temperature mobility is shown to be dominated by remote ionized impurity scattering in wide well samples and by a combination of ionized impurity and interface roughness scattering in narrow well samples.

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