Hole-Mobility Enhancement in Ge-Rich Strained SiGe-on-Insulator pMOSFETs at High Temperatures

Temperature dependence of hole mobility in Ge-rich strained SiGe-on-insulator (SGOI) pMOSFETs was investigated up to 473 K in order to examine the advantage in mobility at temperatures in operating very-large-scale-integrated circuit (VLSI) devices, which are significantly higher than room temperature. High-temperature operation and hole-mobility enhancements are demonstrated up to 473 K for the SGOI-pMOSFETs, which were fabricated by the Ge-condensation technique. The observed drain-current enhancements at 473 K against that of a reference SOI-pMOSFET were almost the same as those at 300 K. Phonon-limited mobility, which ultimately dominates mobility at high temperatures, was extracted by analyzing the temperature dependence of mobility down to 23 K. The extracted phonon-limited mobility exhibited enhancement factors of 12 and 5.5 at 473 K for SGOI devices with Ge fractions of 0.92 and 0.59, respectively, suggesting that such strained-SGOI channels retain the advantage in mobility at elevated temperatures in operating the VLSI devices

[1]  Friedrich Schäffler,et al.  High-mobility Si and Ge structures , 1997 .

[2]  F. Stern,et al.  Properties of Semiconductor Surface Inversion Layers in the Electric Quantum Limit , 1967 .

[3]  T. Tezuka,et al.  High-mobility strained SiGe-on-insulator pMOSFETs with Ge-rich surface channels fabricated by local condensation technique , 2005, IEEE Electron Device Letters.

[4]  S. Laux,et al.  Band structure, deformation potentials, and carrier mobility in strained Si, Ge, and SiGe alloys , 1996 .

[5]  Ulf Konig,et al.  High hole mobility in Si0.17Ge0.83 channel metal–oxide–semiconductor field-effect transistors grown by plasma-enhanced chemical vapor deposition , 2000 .

[6]  F. H. Dacol,et al.  Measurements of alloy composition and strain in thin GexSi1−x layers , 1994 .

[7]  T. Manku,et al.  Electron drift mobility model for devices based on unstrained and coherently strained Si/sub 1-x/Ge/sub x/ grown on silicon substrate , 1992 .

[8]  M. J. Kearney,et al.  The effect of alloy scattering on the mobility of holes in a quantum well , 1998 .

[9]  Yukio Matsumoto,et al.  Scattering Mechanism and Low Temperature Mobility of MOS Inversion Layers , 1974 .

[10]  Bruce M. Clemens,et al.  Strain relaxation kinetics in Si1–xGex/Si heterostructures , 1989 .

[11]  S. Takagi,et al.  On the universality of inversion layer mobility in Si MOSFET's: Part I-effects of substrate impurity concentration , 1994 .

[12]  Shinichi Takagi,et al.  Characterization of 7-nm-thick strained Ge-on-insulator layer fabricated by Ge-condensation technique , 2003 .