Jian Zhang

This paper reports ultralow contact resistivities (ρ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> ) achieved on highly doped p-SiGe with two low-temperature contact formation methods. One method combines precontact amorphization implantation with ~500 °C rapid thermal processing (RTP)-based Ti germano-silicidation; ρ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> achieved was ~2.9 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-9</sup> Ω·cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The other method combines codeposited TiSi-Ti:Si = 1:1-with ~450 °C RTP-based Ti silicidation; ρ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> achieved was ~1.7 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-9</sup> Ω·cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . When Pc reaches minimum, the TiSi(Ge) alloy is generally amorphous with embedded small crystallites, similar to the previous observations on pure Si substrates.

Si-substrate-based AlGaN/GaN high-electron mobility power transistors with low pressure chemical vapor deposition (LPCVD) SiN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>x</i></sub> as gate isolation material are fabricated on a 6-in wafer by CMOS compatible process. The dielectric failure by forward-biased constant-voltage stress time-dependent dielectric breakdown (TDDB) measurements at various temperatures (from room temperature to 250 °C) and their statistical Weibull analysis are compared. Impact of gate dielectric area and multifinger on the SiN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>x</i></sub> TDDB characteristics is also discussed. Using thermal microscope imager, the leakage current spots have been identified. The mean time to failure decreases with the increasing finger numbers in exponential form. We also predict the device ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${W}_{G}= {0.25}$ </tex-math></inline-formula> mm) with 35-nm-thick LPCVD SiN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>x</i></sub> gate dielectric can survive at a positive gate voltage of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {GS}}= {15}$ </tex-math></inline-formula> V for a 10-year time-to-breakdown lifetime (100 ppm and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${T}= {25}$ </tex-math></inline-formula> °C) and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {GS}}= {7.5}$ </tex-math></inline-formula> V for a 10-year time-to-breakdown lifetime (100 ppm and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${T}= {250}$ </tex-math></inline-formula> °C).

We report results of zero-field muon spin relaxation experiments on the filled-skutterudite superconductors ${\mathrm{Pr}}_{1\ensuremath{-}x}{\mathrm{Ce}}_{x}{\mathrm{Pt}}_{4}{\mathrm{Ge}}_{12},x=0$, 0.07, 0.1, and 0.2, to investigate the effect of Ce doping on broken time-reversal symmetry (TRS) in the superconducting state. In these alloys broken TRS is signaled by the onset of a spontaneous static local magnetic field ${B}_{s}$ below the superconducting transition temperature. We find that ${B}_{s}$ decreases linearly with $x$ and $\ensuremath{\rightarrow}0$ at $x\ensuremath{\approx}0.4$, close to the concentration above which superconductivity is no longer observed. The ${\text{(Pr,Ce)Pt}}_{4}{\mathrm{Ge}}_{12}$ and isostructural ${\text{(Pr,La)Os}}_{4}{\mathrm{Sb}}_{12}$ alloy series both exhibit superconductivity with broken TRS, and in both the decrease of ${B}_{s}$ is proportional to the decrease of Pr concentration. This suggests that Pr-Pr intersite interactions are responsible for the broken TRS. The two alloy series differ in that the La-doped alloys are superconducting for all La concentrations, suggesting that in ${\text{(Pr,Ce)Pt}}_{4}{\mathrm{Ge}}_{12}$ pair-breaking by Ce doping suppresses superconductivity. For all $x$ the dynamic muon spin relaxation rate decreases somewhat in the superconducting state. This may be due to Korringa relaxation by conduction electrons, which is reduced by the opening of the superconducting energy gap.