Study of MOSFET IDVG Curve Double Hump Effect

In the traditional CMOS manufacturing process, we often use the IV curve to evaluate the characteristics of the transistor, and sometimes the IdVg curves of the transistor will appear double hump, especially for the NMOS. This paper analyzes mechanism of the double hump phenomenon of the IdVg curve. There are two main causes, one is due to the segregation effect of impurities, and the other is due to the manufacturing process of STI. This article also shares ways to improve this phenomenon.