Comparison between the behavior of submicron graded-channel SOI nMOSFETs with fully- and partially-depleted operations in a wide temperature range

In this work electrical properties of GC SOI nMOSEETs from two different technologies were presented for temperatures ranging between 90K and 380K. It has been shown that the increase of mobility with temperature reduction is larger than for devices with lighter dopind levels. Heavily doped GC from transistors shown constant threshold voltage over the entire temperature range, as it lies close to the ZTC point. Although the temperature lowering leads devices to operate in full depletion, GC devices with thin gate oxide presented GΓFBE effect due to the leakage current reduction. The subthreshold swing of heavily doped GC transistors have shown to depart the theoretical limit for T higher than 250K, indicating a change in the operation mode from fully to partially-depleted.