Reduction of self-heating effect using selective buried oxide (SELBOX) charge plasma based junctionless transistor

Abstract

A junctionless transistor (JLT) having high doping concentration of the channel, suffers from the threshold voltage roll-off because of random dopant fluctuation (RDF) effect. RDF has been minimized by using charge plasma based JLT. Charge plasma is same as a workfunction engineering in which work function of the electrode is varied to create hole/electron plasma and induce doping in the intrinsic silicon. N-type doping is induced at the source and drain side due to difference of workfunction of silicon wafer. In this paper, charge plasma based junctionless MOSFET on selective buried oxide (SELBOX-CPJLT) is proposed. This approach is used to reduce the self-heating effect presented in SOI-based devices. The proposed device shows better thermal efficiency as compared to SELBOX-JLT. 2D-Atlas simulation revealed the electrostatics and analog performance of both the devices. The SELBOX-CPJLT exhibits better electrostatic performance as compared to SELBOX-JLT for the same channel length. The analog performance such as intrinsic gain, transconductance generation factor, output conductance and unity gain cut-off frequency are extracted from small signal ac analysis at 1 MHz and compared to SELBOX-JLT. The analysis of the thermal circuit model of SELBOX structure is also performed.