학술논문

High-Speed Steep-Slope GaInAs Impact Ionization MOSFETs (I-MOS) With SS = 1.25 mV/dec—Part II: Dynamic Switching and RF Performance
Document Type
Periodical
Source
IEEE Transactions on Electron Devices IEEE Trans. Electron Devices Electron Devices, IEEE Transactions on. 69(7):3549-3556 Jul, 2022
Subject
Components, Circuits, Devices and Systems
Engineered Materials, Dielectrics and Plasmas
Logic gates
Transistors
Switching circuits
Inverters
Switches
Threshold voltage
Hysteresis
Atomic layer deposition (ALD)
GaInAs
I-MOS
impact ionization
SS<%2Fitalic>%29%22">inverse subthreshold slope (SS)
MOSFET
RF performance
steep slope
Language
ISSN
0018-9383
1557-9646
Abstract
Part I of this work described narrow bandgap GaInAs-based I-MOS devices with a minimum steep slope $SS_{min}$ = 1.25 mV/dec maintained over 4 orders of magnitude in drain current, ${I}_{ \mathrm{\scriptscriptstyle ON}}/{I}_{ \mathrm{\scriptscriptstyle OFF}}$ ratios >10 6 at 300 K (>10 9 at 15 K), and low operating voltages for a gate length of ${L}_{G} $ = 100 nm. Part II focuses on the device time-domain switching capabilities and RF performance. Digital switching tests using a hybrid connected inverter reveal excellent capabilities for high clock rate operation. Simple circuit estimates indicate that the present 100 nm GaInAs I-MOS can operate with clock frequencies >10 GHz. The impact-ionization-induced hysteresis in the ${I}_{D}$ – ${V}_{GS}$ I-MOS characteristics does not play any role in dynamic switching of a digital inverter: the ${n}$ -channel pull-down transistor turns on with a steep slope, but turns off classically with a higher threshold voltage which reduces the dynamic power dissipation per switching cycle. Factors impacting GaInAs I-MOS reliability are considered, and a physically motivated approach to enhance the reliability of III–V MOSFETs is proposed. We show that GaInAs-based I-MOS devices offer high analog cutoff frequencies and low-noise characteristics, suggesting applicability for digital and RF applications on a single technological platform. When benchmarked against other steep-slope technologies, GaInAs I-MOS shows the strongest steep slope, competitive ${I}_{ \mathrm{\scriptscriptstyle ON}}/{I}_{ \mathrm{\scriptscriptstyle OFF}}$ ratios, and lowest operating voltage of any I-MOS transistor to date, without any back-gate/substrate bias.