Bias Temperature Stress Instability of Multilayered MoS2 Field-Effect Transistors With CYTOP Passivation

Bias temperature stress instability on multilayered MoS
₂
FETs was systematically investigated with the device scheme encapsulated with amorphous fluoropolymers [cyclized transparent optical polymer (CYTOP)] for the secure of minimization of external gas ambient effects. Large threshold voltage shifts (ΔV
_th
) for the negative bias temperature stress (NBTS) were observed, compared to the positive bias temperature stress (PBTS). Herein, the asymmetry behaviors on ΔV
_th
, observed in this paper, are ascribed to the sulfur vacancy in MoS
₂
layers, leading to large hole traps compared to electron traps in MoS
₂
layers. Moreover, high-temperature-sensitivity [d(ΔV
_th
)/dT] on ΔVth for PBTS than NBTS was observed, and their origins are possibly due to synergetic effects associated with large trap energy distribution (k
_o
T) for electron trap levels.