A study of tilt angle effect on Halo PMOS performance

The Halo structure is usually adopted in deep submicrometer MOS devices for punchthrough prevention. The tilt angle of the Halo implant determines the dopant distribution which induces anti-punchthrough operation. In this paper, we investigate the impact of the tilt angle on the Halo PMOS device performance via two-dimensional (2D) simulations. We find that the ratio of on-current to off-current is constant for all tilt angles of Halo implant, implying an equivalent DC performance for all tilt angles. The equivalence can be traced back to a self compensation between the body factor and source resistance. The result implies that a low tilt angle should be adopted for Halo devices, for it gives a small threshold voltage and thus a high noise margin. The methodology used in analyzing body factor and source resistance can also be applied to analyze other devices.     

Interleaved three-phase forward converter using integrated transformer

An interleaved three-phase forward converter using an integrated transformer is proposed in this paper. This type of converter has the attractive features of flexible voltage conversion ratio, high output current (due to the parallel connection of outputs), near-zero output-current ripple (due to the output-current-ripple cancellation), fast transient response (due to the small effective output-filtering inductance), and is particularly suitable for high-output-current and low-output-voltage applications such as telecommunication and computer systems. The integrated transformer of the proposed converter consists of three step-down transformers on a single magnetic core. The z-parameter (gyrator) model and the equivalent-circuit model of the integrated transformer are derived. Based on the equivalent-circuit model, the principle of operation of the proposed converter is explained. The analysis and design criteria of the basic circuit, the operation of the regenerative LC snubber circuit, the simulation, and experimental verification are also described.     

Elimination of poly-Si gate depletion for sub-65-nm CMOS technologies by excimer laser annealing

Pulsed excimer laser annealing (ELA) is used to reduce the poly-Si gate depletion effect (to <0.1 nm). Low resistivity (0.58 m/spl Omega//spl middot/cm) and high active boron concentration (4/spl times/10/sup 20/ cm/sup -3/) at the gate-oxide interface are achieved while preserving the gate oxide quality and avoiding boron penetration, to meet International Technology Roadmap for Semiconductors requirements for sub-65-nm CMOS technology nodes. ELA is compatible with high-/spl kappa/ dielectric (HfO/sub 2/) and results in significantly lower gate leakage current density as compared with rapid thermal annealing (RTA).     

Impact of barrier deposition process on electrical and reliability performance of Cu/CVD low k SiOCH metallization

Integration of Cu with low k dielectrics provided solution to reduce both resistance-capacitance time delay and parasitic capacitance of BEOL interconnections for 130 nm and beyond technology node. The motivation of this work is to study and improve electrical and reliability performance of two-level Cu/CVD low k SiOCH metallization from the results of diffusion barrier deposition schemes. Barrier deposition schemes are (a) high-density-plasma 250 Å Ta; (b) surface treatment of forming gas followed by high-density-plasma 250 Å Ta and (c) bi-layer of 100 Å Ta(N)/150 Å Ta. In this work, we demonstrated the superior and competency of high-density-plasma Ta deposition for Cu/CVD low k metallization and achieved excellent electrical and reliability results. Wafers fabricated with high-density-plasma Ta barrier scheme resulted in the best electrical yields, >90% for testing vehicles of dense via chains (via size=200 nm) and interspersed comb structures (width/space=200 nm/200 nm). Dielectric breakdown strength of the interspersed comb structures obtained at electric field of 0.3 MV/cm was ∼4 MV/cm.     

Phase-matched four-wave mixing between pumps and signals in a copumped Raman amplifier

We observe four-wave mixing (FWM) between copropagating pumps and signals in a Raman amplifier when the zero-dispersion wavelength of the transmission fiber lies symmetrically between the pump and the signal wavelengths. The resultant FWM products, which grow as they experience Raman gain along the fiber, can degrade the signal's optical signal-to-noise ratio by as much as 10 dB for a Raman ON-OFF gain of 15 dB.     

Economic evaluation of alternative technologies for tartrate stabilisation of wines

Cold stabilisation is a widely used industrial process to prevent tartrate instability in bottled wines. In this article, current knowledge regarding performance and cost of cold stabilisation and alternative technologies for tartrate stabilisation is reviewed. Whilst there have been occasional cost comparisons between cold stabilisation and alternative technologies published in the literature, existing data is not satisfactory to permit an accurate economic evaluation of the different process options. Therefore, alternative technologies to cold stabilisation, including the Westfalia process, nanofiltration and electrodialysis were compared for both technical and economic performance. The engineering calculations and conceptual cost estimates were based on real world data from an Australian winery. Product loss was a key cost driver in differentiating tartrate stabilisation processes. Cold stabilisation was found to be the most economic treatment process irrespective of scale or winery size. Westfalia process and nanofiltration were the next most cost effective options.     

New indole–carbazole hybrids as glass-forming high-triplet-energy materials

New indole–carbazole hybrids are reported as glass-forming high-triplet-energy materials. They were synthesized by the tandem addition–elimination–(Michael) addition reaction of 9-ethyl-9H-carbazole-3-carbaldehyde with 1H-indole or 2-phenyl-1H-indole followed by alkylation with the different agents. The synthesized compounds exhibit moderate thermal stabilities with 5% weight loss temperatures ranging from 281 to 308 °C. Their glass transition temperatures are in the range of 89–143 °C. Most of the new indole–carbazole hybrids in dilute solutions exhibit high triplet energies (2.97–2.99 eV).