Compact modeling for mos transistors: junctionless nanowires and bidimensional channels

Author(s)

Adélcio Marques de Souza

• Document type: Doctoral Thesis
• Press: São Carlos.
• Institution: Universidade de São Paulo (USP). Escola de Engenharia de São Carlos (EESC/SBD)
• Defense date: 2024-02-15

Examining board members

Murilo Araujo Romero; João Antonio Martino; Marcelo Antonio Pavanello; Michelly de Souza; Gilson Inacio Wirth

• Advisor: Murilo Araujo Romero

Abstract

 Facing the imminent saturation of Moore\'s Law, the academic community has been exploring alternatives to the conventional silicon MOSFET, either by innovating on the operating principles of transistors or by adopting newly discovered materials. In this context, this thesis provides an in-depth analysis and proposes a compact modeling approach for two emerging nanodevices: Junctionless Nanowire Field-Effect Transistors (JLNWFETs) and Field-Effect Transistors based on Two-Dimensional Materials (2DFETs).  In the first part of the thesis, a detailed investigation of JLNWFETs is conducted, spanning from operational principles to a meticulous analysis of their operating regimes and specific characteristics. Subsequently, a compact modeling approach is proposed for cylindrical JLNWFETs, centered on the intuitive description of the device as a resistor whose resistivity is controlled by the gate contact. Including short-channel effects and other non-idealities, fully analytical and explicit expressions are derived to describe the charge, capacitance, and electric current characteristics of these transistors.  The second part of this work explores 2DFETs, highlighting the fundamental properties of two-dimensional semiconductors and the unique characteristics they bring to nanoelectronics. Initially, a critical analysis of the state-of-the-art and future prospects for adopting these emerging transistors is conducted. Subsequently, compact models are developed for the electric current characteristics of 2DFETs, covering carrier transport from diffusion-drift to ballistic limits and incorporating various non-idealities.  In summary, this work contributes to the compact modeling of advanced nanotransistors, providing both detailed analyses and fully analytical and explicit approaches to describe these devices, anticipating the demands of the semiconductor industry. (AU)

• FAPESP's process: 18/13537-6 - Compact modelling of MOS transistors based on quantum effects
• Grantee: Adelcio Marques de Souza
• Support Opportunities: Scholarships in Brazil - Doctorate