An Insight Into Self-Heating Effects and Its Implications on Hot Carrier Degradation for Silicon-Nanotube-Based Double Gate-All-Around (DGAA) MOSFETs

Abstract

Silicon-Nanotube-based ultra-thin DGAA MOSFETs have been extensively studied for their superior immunity to short channel effects (SCEs) and better drive current capability; however, the reliability issues owing to self-heating effects (SHEs) and hot carrier injection (HCI) degradation are yet to be investigated systematically. In advanced non-planar device structures, an increase in power density due to ultra-scaled device dimensions can aggravate both the carrier heating as well as lattice heating. In this paper, 3-dimensional (3-D) electrothermal (ET) simulations using coupled hydrodynamic and thermodynamic transport models are performed to analyze the electrothermal behavior and SHEs in ultra-thin DGAA MOSFET. 3-D TCAD simulation parameters are calibrated with the data obtained from the literature. Through advanced 3-D ET simulations, we demonstrate that the device thermal contact resistance adversely influences both the carrier temperature as well as lattice temperature. The implication of SHE on the device output drive current reduction is also analyzed. The effective drive current method is used to observe the impact of SHE on the intrinsic delay of the device. Further, the performance of the device due to HCI is also highlighted. HCI significantly degrades the overall device performance leading to increased gate leakage current. Finally, the reliability issues induced by SHEs with on-chip ambient temperature variations have also been interpreted using Sentauras based TCAD simulator.

Keywords

• DGAA MOSFETs
• silicon-nanotube
• HCI
• SHE
• gate leakage current
• negative-differential-conductance (NDC)