Statistical Leakage Current Analysis of Trapezoidal Tri-Gate FinFET

Abstract

Leakage current due to process variation is a major issue for the devices technologies. Low leakage devices are a key enabler for long-life System-on-Chip applications with ultralow-power standby requirements. This thesis focuses on the study and development of statistical characteristics of Trigate trapezoidal FinFETs for the prediction of leakage current variation and its distribution using Monte-Carlo method. This paper propounds a statistical modeling approach for estimating the leakage distribution of trapezoidal shaped FinFETs (Tz-FinFETs) under random dopant fluctuation. The simulations have been performed using MATLAB. The purpose of a statistical leakage estimation tool is to get a specific leakage distribution of a FinFET device based on process inputs such as the mean threshold voltage (VTh) and standard deviation of VTh due to process parameter variation. The analysis consists of generating RDF in each fin of a multifin device which leads to an investigation of the impact of RDF on device characteristic and device evaluation. The width-dependent device leakage under atomistic random dopant fluctuation for Tri- gate FinFET could not be accurately modeled by conventional square-root approach. This thesis proposes a statistical leakage model which leads to a significant improvement of the leakage estimation. A comparative study of leakage current distribution of trapezoidal and rectangular FinFET reveals the advantages of trapezoidal FinFETs over rectangular FinFETs. We have also incorporated the effect of fin shape on leakage current. Leakage due to Short Chanel Effects(SCE) decreases as fin widths decreases. Statistical leakage currents due to process variation have been simulated for rectangular shape FinFETs (Re FinFETs) and triangular shape FinFET to compare their performance. Leakage Current increases in silicon on insulator FinFETs as the fin cross-sectional shape changes from rectangular to triangular to trapezoidal. The triangular and trapezoidal shape FinFET has better performance i.e low leakage current over conventional rectangular shape FinFET. Additionally this paper demonstrates the effect of number of fins on leakage current