New aspects and mechanism of kink effect in static back-gatetransconductance characteristics in fully-depleted SOI MOSFETs onhigh-dose SIMOX wafers |
| |
Authors: | Ushiki T. Kotani K. Funaki T. Kawai K. Ohmi T. |
| |
Affiliation: | New Ind. Creation Harchery Center, Tohoku Univ., Sendai; |
| |
Abstract: | An extraordinary kink phenomenon in static back-gate transconductance characteristics of fully-depleted SOI MOSFETs has been experimentally investigated and characterized for the first time. This kink phenomenon has been observed in both NMOS and PMOS on high-dose SIMOX wafers under steady-state conditions at room temperature. It was also found that the back-gate characteristics for both NMOS and PMOS show anomalous shift phenomenon in drain current-back gate voltage (I D-VG2) curve at the back-gate voltage corresponding to the kink phenomenon. This kink phenomenon has been attributed to the presence of energetically-localized trap states at SOI/BOX interface. In order to clarify the energy level of the trap states at SOI/BOX interface corresponding to the kink, we have developed a new formula of surface potential in thin-film SOI MOS devices, in which the potential drop across semiconductor-substrate is taken into account. By using this new formula, me have demonstrated that high-dose SIMOX wafers have donor-like electron trap states at ~0.33 eV above the Si midgap with the density of ~N6.0~1012 cm-2 eV -1 and donor-like hole trap states at ~0.35 eV below the Si midgap with density of ~1.5×1012 cm-2 eV-1 at SOI/BOX interface |
| |
Keywords: | |
|
|