Poisson-Schrödinger simulation of inversion charge in FDSOI MOSFET down to 0K - Towards compact modeling for cryo CMOS application

Low Temperature Characterization and Modeling of FDSOI Transistors for Cryo CMOS Applications

“…The onset of the back inversion channel for V b = +3 V is evidenced by an additional plateau in the C gc (V g ) curve, followed by the front channel opening. This effect clearly demonstrates the capacitive coupling, Typical band diagram and electron distribution from PS simulation for a FDSOI structure (V g =1V, t ox = 1 nm, t box = 25 nm, t si = 7 nm, V b = 0 V, T = 4 K. after Aouad et al [41].…”

“…As can be seen, the C gc (V g ) curves are almost temperature independent above threshold, whereas a strong improvement of the turn-on behavior is obtained at low temperature, related to the subthreshold slope increase. These characteristics have been well reproduced by Poisson-Schrodinger simulations (see Section 5.1), providing precise extraction of front oxide EOT values for GO1 and GO2 transistors [41].…”

“…Following the PS simulation results, an analytical model has been established considering that front and back channel charges can be evaluated separately at each interface within a single subband approximation with energy level of a triangular potential well [41]. The coupling between the front and back channels is realized owing to the silicon channel capacitance C si and the charge sheet approximation with Fermi-Dirac statistics.…”

“…the electrical field approaches zero, an offset field F 0 is added to the electric field to account for the flat band quantum confinement [41].…”

“…Figure 23.Typical band diagram and electron distribution from PS simulation for a FDSOI structure (V g =1V, t ox = 1 nm, t box = 25 nm, t si = 7 nm, V b = 0 V, T = 4 K. after Aouad et al[41].…”