A technique to measure spin-dependent trapping events at the metal-oxide-semiconductor field-effect transistor interface: Near zero field spin-dependent charge pumping

摘要

We discuss a new technique to measure spin-dependent trapping events at the metal-oxide-semiconductor field-effect transistor (MOSFET) channel/gate dielectric interface. We call this technique near zero field spin-dependent charge pumping (NZF SDCP). It is based on a powerful MOSFET interface trap characterization measurement called charge pumping and related to an electrically detected magnetic resonance (EDMR) technique called SDCP. NZF SDCP and EDMR SDCP measurements are made on 4H-SiC MOSFETs, and we find that the introduction of nitrogen to the MOSFET interface can have a profound impact on the NZF SDCP response, which suggests that NZF SDCP may be useful to get atomic scale information about MOSFET interfaces such as defect identification. We also find that the NZF SDCP amplitude appears to saturate as a function of charge pumping frequency in most cases but not all. We make model calculations to explain this behavior. We also find that the NZF SDCP spectrum broadens with increasing charge pumping frequency, which may be an inherent NZF SDCP phenomenon. We hypothesize that NZF SDCP may also allow for experimental exploration of some magnetoresistance theories regarding interaction times between charge carriers and traps.