Lateral Non-Uniformity Charges Influence on Interface Trap Density (Dit) by Terman Method in the nMOS Fabrication

Generally speaking, the oxide interface quality can be determined by the interface trap density (Dit) distribution. In this paper, the Dit quantity obtained from the Terman method, which it is assumed that the Dit is equal to zero at the beginning for simulating the Dit effect in ultra-thin oxide. However, the lateral non-uniformity charges have existed in the oxide layer, which maybe obtained an equivalent Dit density not equal to zero also producing an equivalent Dit value. And, such faked Dit will be resulted in an error in high frequency measurement. Fortunately, it can be solved by differentiating technique to obtain an accuracy Dit quantity.