Impact of source doping on the performance of vertical InAs/InGaAsSb/GaSb nanowire tunneling field-effect transistors

Abstract

In this paper, we analyze experimental data from state-of-the-art vertical InAs/InGaAsSb/GaSb nanowire tunneling field-effect transistors (TFETs) to study the influence of source doping on their performance. Overall, the doping level impacts both the off-state and on-state performance of these devices. Separation of the doping from the heterostructure improved the subthreshold swing of the devices. The best devices reached a point subthreshold swing of 30 mV/dec at 100 x higher currents than previous Si-based TFETs. However, separation of doping from the heterostructure had a significant impact on the on-state performance of these devices due to effects related to source depletion. An increase in the doping level helped to improve the on-state performance, which also increased the subthreshold swing. Thus, further optimization of doping incorporation with the heterostructure will help to improve vertical InAs/InGaAsSb/GaSb nanowire TFETs.

Recent advances in III-Sb nanowires: from synthesis to applications

“…Both devices presented a much higher current than the reported Si-based TFETs. Further study of source doping reduced the subthreshold swing to 30 mV/dec (figures 8(b)-(c)) [30]. This series of reports show that the performance of a TFET can be improved by (i) better electrostatic control with better gate stack, (ii) composition engineering of the junctions and (iii) optimized source doping.…”

“…Heterostructures of NW are integrated for different applications like a NW-based light emitter (LED and laser), waveguide, TFET, solar cell and thermoelectric. For example, an InAs/GaSb-based axial p-n junction was used to fabricate a state-of-the-art TFET [30]. Mid-IR lasing was investigated in a GaAsSb-based axial NW structure [31].…”

“…(c) Subthreshold slope versus drain current for a TFET with a different source doping level. Device A has a higher source doping level[30] (reproduced from[30]. © IOP Publishing Ltd. All rights reserved).…”

Quantum simulation investigation of work-function variation in nanowire tunnel FETs

“…The device we studied has 3.5 nm diameter and it is beyond the status of the art of nanowire growth, i.e. diameter of 7 nm [15]. The fabrication steps of the device which we are simulating can refer to the flow chart of processing reported by Lund group where the vapor-liquid-solid growth method combined with digital etching technique is utilized [15].…”

“…diameter of 7 nm [15]. The fabrication steps of the device which we are simulating can refer to the flow chart of processing reported by Lund group where the vapor-liquid-solid growth method combined with digital etching technique is utilized [15]. In order to study the WFV effects, TiN metal gate is employed.…”