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We have investigated single crystal Nb-doped SrTiO3 in terms of its potential utility in nonvolatile memory applications. Compared with polycrystalline oxide (Nb2O5, ZrO x and Cr-SrTiO3), the Pt/single crystal Nb:SrTiO 3 Schottky junction exhibits excellent memory characteristics including uniformity of set/reset bias, die-to-die reproducibility, data retention at high temperature, reliability under cycle stress, and multi-bit operation characteristics. The switching mechanism might be explained by modulation of the Schottky barrier height by charge trapping at the interface

We have investigated the effect of high-pressure hydrogen annealing (HPHA) on fully depleted silicon-on-insulator (SOI) metal-oxide semiconductor field-effect transistors (MOSFETs). The relatively high interface state density of back interface induces significant performance degradation due to the strong interface coupling effect between the front and back interface. To reduce this problem, we performed HPHA in 100% hydrogen ambient at 10 atm. We found that HPHA can significantly reduce the interface state density of both front and back interfaces, which in turn improves electron mobility. Considering the simple process condition and improved electrical characteristics, HPHA is a promising process technology for SOI MOSFETs.

The existence of series resistance in metal–oxide–semiconductor (MOS) devices can result in both the degradation of capacitance at a high frequency and the decrease in conductance. Using a conventional conductance method that does not consider the series resistance, the interface trap density can be underestimated. We propose an improved conductance method based on an equivalent circuit model including the series resistance. Compared with the conventional method, this new method enables the accurate determination of interface trap density.

The electrical characteristics were evaluated for the metal-oxide-semiconductor (MOS) devices with Ti and Pt gates on the atomic-layer-deposited (ALD) HfO2. The equivalent oxide thickness (EOT) of the Ti gate is shown to be nearly the same as that of the Pt gate, which means that a negligible chemical reaction occurs between the gate and dielectric. The values of the effective metal work function (Φm,eff), extracted from the conventional relations of flatband voltage versus EOT, were ∼4.2eV for Ti and ∼5.4eV for Pt, respectively. However, somewhat higher values of Φm,eff were extracted by considering the existence of an interfacial layer and the high negative charge at an interface between HfO2 and interfacial layer. The exact values of Φm,eff were ∼4.37eV for Ti and ∼5.51eV for Pt, respectively. Therefore, the Ti gate is compatible with ALD-HfO2 and can be a candidate for n-type MOS devices.

The capacitance-voltage (C-V) characteristics with and without light illumination were evaluated for a capacitor with a Pt gate on the atomic-layer-deposited HfO2 dielectric. The flat-band voltage (V fb) is conventionally determined by a C-V curve. However, the extracted values of V fb were dependent on the C-V sweep direction and the starting voltage of the sweep (V start). The increasing differences between V start and intrinsic V fb (V fb,i) results in the increasing deviations of V fb from V fb,i. Therefore, the value of V start should be close to V fb,i and different values of V start must be applied to the devices with significantly different V fb,i.