Performance Comparison of Nanosheet FET, CombFET, and TreeFET: Device and Circuit Perspective

Abstract

In this article, the comparison of nanosheet (NS) FET, CombFET, and TreeFETs at advanced technology nodes is performed. Initially, the DC metrics like $I_{\mathrm {ON}}$ , $I_{\mathrm {ON}}/I_{\mathrm {OFF}}$ and $I_{\mathrm {D}} - V_{\mathrm {DS}}$ are dominated by TreeFET compared to Comb and NSFET. The TreeFET exhibits higher $I_{\mathrm {ON}}$ and ensures high-performance (HP) applications at advanced nodes. However, the NSFET continues as a better performer towards low power (LP) applications. The TreeFET dominates the performance and switching performance for temperature variation. At lower temperatures, the NS, Comb, and TreeFETs have a marginal impact on $I_{\mathrm {OFF}}$ . The analog performance is dominated by TreeFET due to higher $I_{\mathrm {ON}}$ . The NSFET exhibits lower $C$ gd and $C$ gs due to the absence of interbridges (IB) between channels. The RF performance is also dominated by Comb and TreeFETs due to the presence of IBs. Further, TreeFET based CMOS inverter outperforms in terms of switching current ( $I_{\mathrm {SC}}$ ) compared to the NSFET and CombFET counterparts. The 27-stage ring oscillator (RO) performance of TreeFET dominates Comb and NSFET with 11.56 GHz ensuring driving radio frequency applications. Thus, the paper will give deep insights into the performance of emerging FETs at both device as well as circuit levels.

Keywords

• CombFET
• TreeFET
• NSFET
• temperature
• CMOS inverter
• ring oscillator