Investigation of high-K dielectrics for single- and multi-gate FETs

The continuous drive to enhance semiconductor performance has led to significant advancements in MOSFETs. As device miniaturization approaches its fundamental limits, traditional gate dielectrics like SiO₂ suffer from performance degradation due to increasing leakage currents and gate tunneling effects. To address these challenges, the incorporation of high-k gate dielectrics has emerged as a critical solution. This chapter highlights the importance of high-k gate dielectrics in multi-gate FETs. First, it addresses the limitations of conventional SiO₂ as the gate insulator, emphasizing the constraints posed by the thickness scaling to preserve the gate control over the channel. Second, it explores the remarkable properties of high-k materials, such as higher permittivity, lower gate leakage, and improved carrier mobility, which effectively overcome the obstacles faced by traditional gate dielectrics. A nanosheet FET has been designed wherein the impact of high-k dielectrics on different temperatures, single-k, and dual-k spacer materials is examined.