Abstract: A semiconductor device including a first electrode, a second electrode, an oxide semiconductor disposed between the first electrode and the second electrode, and a first oxide layer containing a predetermined element, oxygen, and an additional element and disposed between the first electrode and the oxide semiconductor, wherein the predetermined element is at least one of tantalum, boron, hafnium, silicon, zirconium, or niobium, and the additional element is at least one of phosphorus, sulfur, copper, zinc, gallium, germanium, arsenic, selenium, silver, indium, tin, antimony, tellurium, or bismuth.

Abstract: A method for measurement of amplitude of a periodic signal which is noise-robust, free of the effects of leakage of the frequency component, and free of any unbalance between the + side amplitude and ? side amplitude, comprising (i) converting a periodic signal to a digital signal, (ii) applying a discrete Fourier transform to this digital periodic signal, calculating the magnitudes and phases of a fundamental frequency component and harmonic frequency components of the periodic signal in the frequency domain, (iii) applying an inverse discrete Fourier transform to the calculated frequency components to reconstruct the waveform in the time domain, and (iv) measuring the amplitude of the periodic signal from the waveform data at the center part of the reconstructed waveform on the time axis.