Characterization of SOI-MOSFET with the channel conductance transient spectroscopy

A new technique, channel conductance transient spectroscopy (CCTS), for measuring traps at the SiO₂-Si interface and in the bulk of small-sized MOSFETs is introduced in detail. Constant capacitance deep level transient spectroscopy (CC-DLTS) can not be applied to small-sized MOSFETs due to their small gate capacitance depending on their gate area. CCTS offers the solution for this fundamental problem. The channel conductance of the MOSFET in linear region strongly depends upon the the gate voltage rather than the gate area. Trapped carriers in interface traps and bulk traps influence the threshold voltage and as a result change the channel conductance. The exponential emission of carriers out of traps causes corresponding transients of channel conductance. The channel conductance transients are correlated with lock-in correlator. Interface trap density (D_it ) and concentration(N_t) of bulk traps can be evaluated. This new measurement technique is very sensitive and reliable. CCTS is a unique measurement technique which can characterize not only the interface state but also the bulk traps in small-sized MOSFETs. The results of ZMR-SOI-MOSFETs are presented