Invited Paper EM-ThA8
High-k/III-V Integration: from GaN to InSb

Thursday, October 18, 2007, 4:20 pm, Room 612

The principal obstacle to III-V compound semiconductors rivaling or exceeding the properties of Si electronics has been the lack of high-quality, thermodynamically stable insulators on GaAs (or on III-V materials in general). For more than four decades, the research community has searched for suitable III-V compound semiconductor gate dielectrics or passivation layers. The literature testifies to the extent of this effort with representative, currently active approaches including sulfur passivation, silicon interface control layers (Si ICLs), in situ molecular beam epitaxy (MBE) growth of Ga2O3(Gd2O3), ex situ atomic layer deposition (ALD) growth of Al2O3 and HfO2, jet vapor deposition (JVD) of Si3N4, ALD, PVD or MBE of HfO2 + Si or Ge ICL, Al2O3 plasma nitridation or AlN passivation. The research on ALD approach is of particular interest, since the Si industry is getting familiar with ALD Hf-based dielectrics and this approach has the potential to become a manufacturable technology. In this talk, the authors will review some of our previous work on integration of ALD high-k dielectric Al2O3 on GaAs, InGaAs and GaN, and demonstration of high performed depletion-mode III-V MOSFETs. But for very large scale integrated (VLSI) circuits or high-speed digital applications, enhancement-mode (E-mode) III-V MOSFETs within the Si CMOS platform are the real devices of interest. We will discuss on the detailed CV measurements (high frequency-low frequency CV, Quasi-static CV, split-CV, and photo-CV) on high temperature annealed ALD Al2O3 and HfO2 dielectrics on GaAs and InGaAs. InGaAs includes In0.2Ga0.8As/GaAs, In0.53Ga0.47As/InP and other In-rich InGaAs materials. We will focus on some new results on inversion-type E-mode NMOSFET fabricated on p-type In0.53Ga0.47As, and InP surfaces using ALD Al2O3 and HfO2 dielectrics. The maximum inversion current of ~ 400 mA/mm and Gm of ~ 130 mA/mm and the middle gap interface trap density Dit of low 10x11/cm2-eV to 2x1012/cm2-eV is achieved at these material systems. We will also briefly report on some new CV results on high-k/InSb surface. The work is in close collaborations with G.D. Wilk, Y. Xuan, H.C. Lin, Y.Q. Wu, T. Shen, T. Yang, Z. Cheng, A. Lochtefeld, J. Woodall, M. Lundstrom, M.A. Alam, R.M. Wallace, J.C.M. Hwang, A. Liu, W. Wang, M. Santos. We also would like to thank B. Yang, M. Hong, R. Kwo, H. Gossmann, K.K. Ng, J. Bude and others who contributed significantly at the initial stage of this research.