Effect of the temperature on on Junctionless Nanowire Transistors electrical parameters down to 4K

Abstract

The aim of this work is to analyze the operation of Junctionless Nanowire Transistors at liquid helium temperature, focusing the operation at linear regime. The drain current, the transconductance, the low field mobility, subthreshold slope, the interface trap density and the channel resistance are the key parameters under analysis.

Theoretical Limit of Low Temperature Subthreshold Swing in Field-Effect Transistors

“…Additionally, this approach has led to unreasonably high N it at deep-cryogenic temperatures in the literature. 8,16,18,19 Typical N it values that have been extracted in this way are in the order of 10 13 − 10 14 cm −2 at 4.2 K, and 10 16 cm −2 at 20 mK. 8 The values at 4.2 K are still possible in principle.…”

“…Since (18) shows that SS bt has the right dependence on T above T crit where the diffusion current dominates, SS bt also serves as a good approximation of the complete SS of the total current. This will be investigated next.…”

“…The proposed SS theory with band-tail tunneling solves the problem of anomalously high Nit that are obtained from the Boltzmann limit in the literature on FETs at deep-cryogenic temperatures. 2,8,16,18,19 The rows at 36, 20, and 4.2 K are from Fig. 2(b).…”

“…III B, and the Boltzmann limit, SS = m · (k B T /q) ln 10, which is often falsely extrapolated to deepcryogenic temperatures in the literature. 8,16,18,19 In both models, the slope factor is given by m = m 0 + qN it /C ox , where we assume a uniform density of interface traps over energy. The idea behind the assumption of uniformity is explained in more detail in Fig.…”

“…8 As shown in Fig. 1, this degradation is measured in structurally different FETs, operating in subthreshold at both low and high drain-to-source voltage, V DS , and among various technology nodes: mature and advanced bulk and FDSOI MOSFETs, [4][5][6][7][8][9][10][11][12][13][14] FinFETs, 15,16 gate-all-around Si nanowires, 17 junctionless nanowires, 18,19 SiGe FETs, 20 InP HEMTs, 21 SiC FETs, 22 to name a few. Fig.…”