Advanced FDSOI Device Design: The U-Channel Device for 7 nm Node and Beyond

Abstract

In this paper, we propose the extendibility of ultra-thin body and box (UTBB) devices to 7 and 5 nm technology nodes focusing on electrostatics. A difficulty in scaling traditional UTBB is the need for SOI scaling to about one fourth of the gate length. We propose a U-channel fully depleted silicon on insulator architecture that starts off with a thicker SOI (8-11 nm) and has a U-shaped channel enabled by a recessed metal gate. This device improves the electrostatics by increasing the overall gate length at fixed metal gate opening, mitigating drain field coupling to the source due to the recessed metal gate region and having thin SOI below the center of the device (4-5 nm). Modeling shows that good electrostatics can be maintained at small metal gate opening to enable pitch scaling. This device provides lower cost options for mobile and IOT technologies.

Keywords

• UTBB
• U-channel
• TCAD
• multiple thresholds