The specific thermal resistance values of several interface materials (TIMs) intended to thermally enhance Cu contact pairs and their degradation under isothermal ageing at 170 °C have been investigated using stack samples consisting 10 discs 9 layers the TIMs. results obtained indicate that as-prepared samples, one with conductive Ag grease, Sn–3.5Ag solder joints 25 μm thick Sn foil as TIMs are significantly lower than those sample without any TIM. However, after for 90 days, these not...

We report on the properties of p-type delta-doped layers prepared in molecular beam epitaxy-Si by growth interruption and evaporation elemental B. Secondary-ion mass spectrometry measurements at several primary ion energies have been used to show that full width half maximum is ∼2 nm. Hall confirm are completely activated 300 K with a mobility 30±5 cm2/V s for carrier density (9±2)×1012 cm−2. At temperatures below 70 nonmetallic behavior observed which we attributed conduction between...

Measurements of Shubnikov de Haas oscillations in the temperature range 0.3–2 K have been used to determine an effective mass 0.23 m0 a Si/Si0.87Ge0.13/Si two-dimensional hole gas. This value is agreement with theoretical predictions and that obtained from cyclotron resonance measurements. The ratio transport time quantum lifetime found be 0.8. It concluded 4 mobility 11 000 cm2 V−1 s−1 at carrier sheet density 2.2×1011 cm−2 limited by interface roughness short-range charge scattering.

The effective masses in remote doped Si/Si0.8Ge0.2/Si quantum wells having sheet densities, Ns the range 2×1011–1.1×1012 cm−2 have been determined from temperature dependencies of Shubnikov–de Haas oscillations. values obtained increase with magnetic field and Ns. This behavior is taken as evidence for nonparabolicity valence band accounts discrepancies previously reported masses. Self-consistent structure calculations a triangular confinement carriers also carried out provide confirmation...

The effective masses in remote doped Si/Si1−xGex hole quantum wells with 0.05≤x≤0.3, have been determined from the temperature dependence of Shubnikov–de Haas oscillations. values are lower than previously observed by other workers, but still somewhat higher theoretical Γ-point for ground-state heavy subband. differences attributed to finite carrier sheet densities and can be satisfactorily accounted nonparabolicity corrections.

Measurements of sheet resistance and Hall coefficient between 0.3 K 30 have been used to infer two-dimensional weak localization hole-hole interaction effects in Si:B delta-doped layers. It is found that the renormalized screening parameter theory F* approximately 0.9 for samples concentrations 1.8*1013 cm-2 7.6*1013 only weakly dependent on carrier concentration, agreement with theory. The correction provides evidence spin-orbit scattering, which appears become increasingly important as...

We report measurements of the magnetoresistance and Hall coefficient a two-dimensional hole gas defined at remote-doped Si/${\mathrm{Si}}_{0.8}$${\mathrm{Ge}}_{0.2}$ heterojunction. In addition to usual quantum interference interaction corrections, one can clearly resolve effects relating temperature dependence static dielectric function, strain-induced suppression spin-orbit scattering, anisotropy g factor. A number issues worthy further theoretical study are suggested.

We have measured the energy loss rate as a function of carrier temperature for hot holes in Si/Si0.8Ge0.2 quantum wells with sheet densities range (3–7)×1011 cm−2 at lattice temperatures 0.35 and 2.0 K. Calculations acoustic phonon deformation potential scattering coupling constant 4.5 eV show good agreement measurement. The is consistent linear interpolation between bulk Si Ge values that deduced from measurements thermopower similar samples. In contrast to previous work, we find no...

X-ray diffraction has been used to deduce the width and strain fields of an elemental boron delta layer in (100) Si grown by MBE. It is found be <1 nm thick tetragonally distorted with a lattice contraction 0.031 direction. Hall measurements have obtain hole concentration it that fully activated sheet carrier density 3.5*1014 cm-2, one highest values reported date. Cross-sectional TEM analysis confirms near-ideal layer, no precipitation evident.

We discuss the mechanical and thermal design of a high temperature pressure-mounted base-plate-less power module for application in continuous (150°C) ambient. The resistance potential interface materials (TIMs) has been measured as function contact pressure applied with samples aged under at 170°C. results show significant ageing all TIMs having broadly similar after 90 days. As anticipated resistances lower 1.4MPa are somewhat higher than those 3MPa whilst measurements 200W 350W no...

The electrical conductivity of the 2DHG formed at interface has been measured on samples with composition 0.05<x<0.29 and carrier sheet densities between in temperature range 0.3 K to 1.6 K. It is found that (T) dependence described by superposition a screening term linear T logarithmic associated weak localization - interactions. We find no evidence for as predicted consequence lifetime broadening. results are satisfactory quantitative agreement Gold Dolgopolov's theory short-range...

The fabrication of the first boron delta doped field-effect transistor is described. Molecular beam epitaxy was used to grow layers and a low temperature processing schedule has been adopted, including use plasma enhanced oxide growth form gate dielectric.

Abstract The magnetoresistance of Si:B delta layers sheet concentrations 2 × 1013 to 8 cm−2 has been measured at temperatures down 0·3 K and in fields up 12 T both parallel perpendicular the 2D hole gas. results have compared with weak localization theory incorporating spin-orbit scattering, Zeeman orbital terms interaction theory. It is concluded that a promising alternative explanation be found concept wavefunction shrinkage, metal-insulator transition strongly localized state being...

Power integrity is becoming increasingly relevant due to increases in device functionality and switching speeds along with reduced operating voltage. Large current spikes at the terminals result electromagnetic disturbances which can establish resonant patterns affecting operation of whole system. These effects have been examined using a finite difference time domain approach solve Maxwell's equations for PCB power ground plane configuration. The simulation terminated uniaxial perfectly...

The authors present the results of low-temperature transport measurements on 'metallic' Si:Sb doping layers with nominal widths 10 nm, 20 nm and 80 nm. There is clear evidence weak localization interaction corrections to coefficients for a 3D 2D transition as layer width decreases-the first observation these effects in this system. Of particular interest fact that experimental are good quantitative agreement most aspects theory, despite highly disordered multi-sub-band nature samples.

We report on two methods which illustrate piezoelectric echects in the strained Si (100)Siι -/Ge system.The non-contact sound excitation technique has been used to reveal conversion of a high-frequency electric fleld E into acoustic waves at 77 K can also be modulated by dc applied bias voltage (±30 V).The sample was an MBE grown modulation doped S i 0 .8 8 G e . 1 2 / ( ) í s t r u c w h d n y .0 x 01and 4.2 mobility 10500 cm2 V -1 s-1 .We deduce that observed field wave is associated with...

The galvanomagnetic properties of a boron δ-layer in epitaxial silicon (carrier concentration 7·1013 cm‒2) weak magnetic fields (from 10‒3 T to 2 T) at temperatures 1.7−50 K is reported. It shown that the temperature dependence conductivity attributable simultaneous occurrence effects localization presence spin–orbit interaction and hole–hole diffusion channel. In an investigation magnetoconductivity Hall effect contributions are separated, their characteristic parameters determined....