Impact of Junction Nonabruptness on Random-Discrete-Dopant Induced Variability in Intrinsic Channel Trigate Metal–Oxide–Semiconductor Field-Effect Transistors

Abstract

Using full three-dimensional (3D) technology computer-aided design (TCAD) simulations, we present a comprehensive statistical study on the random discrete dopant (RDD) induced variability in state-of-the-art intrinsic channel trigate MOSFETs. This paper is focused on the RDD variability sources that are introduced by dopant diffusion from highly doped source/drain (S/D) regions into the undoped channel region, which is referred to as junction nonabruptness (JNA). By considering a realistic lateral doping profile in the channel and evaluating the impact of JNA on the variability of performance parameters such as threshold voltage (V th), subthreshold slope (SS), drain-induced barrier lowering (DIBL), on current (I on), and off current (I off), we show that the effect of JNA can lead to substantial device variations. The nonnegligible influence of JNA puts limitations on device scaling, which is also investigated in this paper.

Impact of random discrete dopant in extension induced fluctuation in gate–source/drain underlap FinFET

“…[4][5][6] There has been extensive study on RDD and a combination impact on FinFET with other variation sources, such as line edge roughness, work function variation and random interface traps. [7][8][9][10][11][12][13][14][15] However, most of the study has focused on the random dopants induced fluctuation in the channel region no matter it is doped or intrinsic with lateral dopants diffusing from the extension region, which can be referred as gatesource/drain (G-S/D) overlap. The RDD effect in extension region has not drawn enough attention.…”