Interface dipole modulation for gate dielectrics in Field-Effect transistors: a review

Abstract

Interface dipole engineering has recently become a key technology in the fabrication of semiconductor FETs. This review comprehensively covers the principles, methods, and applications of interface dipoles in gate dielectric structures. We discuss the evolution from traditional SiO2/poly-Si structures to high-K/metal gate structures, and emphasize the influence of interface dipoles on device electrical characteristics. We examine the mechanisms for interface dipole formation in terms of electronegativity differences, charge transfer, and structural considerations, comparing and reviewing several models. We also cover implementation methods such as layers, interfaces, and positions for forming dipoles, and compare the effects of various combinations. This technology enables device implementation, which has become challenging due to CMOS scaling limitations. This review also discusses the applicability in new device platforms such as two-dimensional material semiconductors and ferroelectric FETs. We review current challenges and future research directions and emphasize the increasing importance of this technology in next-generation semiconductor development. This comprehensive review provides valuable insights from materials science and semiconductor device engineering perspectives.