학술논문

4H-SiC MOSFETs With Borosilicate Glass Gate Dielectric and Antimony Counter-Doping
Document Type
Periodical
Source
IEEE Electron Device Letters IEEE Electron Device Lett. Electron Device Letters, IEEE. 38(10):1433-1436 Oct, 2017
Subject
Engineered Materials, Dielectrics and Plasmas
Components, Circuits, Devices and Systems
Annealing
Silicon carbide
MOSFET
Temperature measurement
Logic gates
Dielectrics
Capacitance-voltage characteristics
4H-SiC MOSFET
channel mobility
interface trap density
counter-doping
Language
ISSN
0741-3106
1558-0563
Abstract
In this letter, it is demonstrated that 4H-SiC MOSFETs with borosilicate glass (BSG) as the gate dielectric result in significantly higher channel mobility than standard nitride oxide annealed devices, due to lower density of near-interfacial traps at the BSG/SiC interface. Using a thin Antimony-doped surface layer in conjunction with the BSG dielectric results in higher channel mobility at room temperature. The field-effect channel mobility of such devices is found to be 180 ${\rm {cm}}^{{2}}/{\text {V}}\cdot \text {s}$ at low transverse electric fields (close to threshold) and 94 ${\text {cm}}^{\text {2}}/{\text {V}}\cdot \text {s}$ at high fields (~2 MV/cm), which is about a factor of five higher than the state-of-the-art. This, along with a tunable threshold voltage, could make this approach very attractive for power MOSFET applications. However, the poor bias temperature instability of BSG is a big challenge for utilization of this dielectric.