HighTemperature Operation of nMOSFET on Bonded SOI

This paper describes high-temperature operation of nMOSFET on bonded SOI. A long-channel nMOSFET is fabricated on bonded SOI (Si layer thickness 0.3 ?>m), SOS (Si layer thickness 0.3 ?>m), and bulk Si, Bonded SOI is produced using pulse-field-assisted bonding and resistivity-sensitive etching. The high-temperature operation of bonded SOI nMOSFET is demonstrated and compared with SOS and bulk MOSFETs. The leakage current variation with temperature is significantly smaller in bonded sal and in SOS than in bulk MOSFETs. At high temperatures, the drain current to leakage current ratio is 100 times higher in bonded SOI than in SOS and bulk devices. At 300°C. a ratio of 10⁴ is obtained for the bonded SOI nMOSFET. The ratio is expected to be even higher if a reduced channel length and ultrathin (less than 0.1 ?>m) bonded SOI is used.