Compact modeling of the subthreshold characteristics of junctionless double-gate FETs including the source/drain extension regions. (June 2019)

• Record Type: Journal Article
• Authors: Bae, Min Soo; Yun, Ilgu
• Is Part Of: Solid-state electronics. Volume 156(2019)
• Page Start: 48
• Page End: 57
• Publication Date: 2019-06
• Subjects: Junctionless double-gate FET -- Compact model -- Source/drain extension regions -- Poisson equation -- Subthreshold region; Semiconductors -- Periodicals; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.sse.2019.03.064
• Languages: English
• ISSNs: 0038-1101

Abstract

Highlights: Analytical model for the junctionless DG FET with and without the source/drain extension regions. Approximation for solving 2D Poisson equation, which does not require any iteration. Analysis of the effect of the source/drain extension regions on short channel effects. Comparative study of a junctionless DG FET and a conventional undoped DG FET. Abstract: With the gate length shrinking to a few tens of nanometers, junctionless double-gate field-effect transistors (JL DG FETs) have become widely studied. In the subthreshold region, the electrical characteristics of JL DG FETs are sensitive to device parameters such as channel length, channel thickness, oxide thickness, doping concentration, and whether there are source/drain (S/D) extension regions or not. Therefore, it is essential for device engineers to develop compact models to run circuit simulations. In this paper, a compact JL DG FET model including S/D extension regions in the subthreshold region is proposed. Based on the superposition of the 1D Poisson equation and the 2D Laplace equation, the potential model is developed with and without S/D extension regions. Moreover, the subthreshold current, subthreshold slope, threshold voltage, and the drain induced barrier lowering are extracted without numerical iteration. The modeling results were verified with an ATLAS TCAD simulator and compared with a conventional undoped DG FET. We showed that the JL DG FET using the proposed compact model has better short-channel characteristics than the undoped DG FET with S/D extension regions, and we recommend that the doping concentration in the JL DG FET should be lighter for better subthreshold characteristics.