In this paper, we report an experimental investigation of electron mobility in ultrathin SOI MOSFETs operated in double-gate mode. Mobility is measured for silicon thickness down to approximately 5 nm and for different temperatures. Mobility data in single- and double-gate mode are then compared according to two different criteria imposing either the same total inversion charge density or the same effective field in the two operating modes. Our results demonstrate that for silicon films around 10 nm or thinner and at small inversion densities, a modest but unambiguous mobility improvement in double-gate mode is observed even if the same effective field as in the single-gate mode is kept. Furthermore, we also document that mobility in double-gate mode can remarkably improve above single-gate mobility when the comparison is made at the same total inversion density. This latter feature of the double-gate operating mode can be very beneficial in the perspective of very-low voltage operation.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering
- Deep-submicron MOSFETs
- Lowfield mobility
- Silicon thickness dependence
- Ultrathin SOI MOSFETs