The impacts of high tensile stress CESL and geometry design on device performance and reliability for 90 nm SOI nMOSFETs

The thickness effects of high-tensile-stress contact etch stop layer (HS CESL) and impact of layout geometry (length of diffusion and gate width) on mobility enhancement of 100/(100) 90 nm SOI nMOSFETs were studied in detail. Additionally, we also inspected the low frequency characteristic with low-frequency noise investigation for FB-SOI nMOSFETs. Experimental results show that devices with 1100 Å HS CESL possess worse characteristics and hot-carrier-induced degradations than devices with 700 Å HS CESL due to serious stress-induced defects happen. The lower plateau of Lorentzian noise spectrum observed from input-referred voltage noise (S_vg) implies higher leakage current for the devices with 1100 Å HS CESL. On the other hand, we found that devices with narrow gate widths possess higher driving capacity because of larger fringing electric fields and higher compressive stress in direction perpendicular to the channel. Owing to the more serious impact of compressive stress in direction parallel to the channel, the device performance was degraded particularly for devices with shorter LOD.     

Design and fabrication of deep submicron CMOS technology compatible suspended high-Q spiral inductors

In this paper, deep submicron complementary metal-oxide-semiconductor (CMOS) process compatible high-Q suspended spiral on-chip inductors were designed and fabricated. In the design, the electromagnetic solver, SONNET, and the finite element program, ANSYS, were used for electrical characteristics, maximum endurable impact force, and thermal conduction simulations, respectively. Based on the design, suspended spiral inductors with different air cavity structures, i.e., diamond opening, circle opening, triangle opening, and full suspended with pillar supports were developed for various applications. Among these structures, the suspended inductor with pillar support possesses the highest Q/sub max/ (maximum of quality factor) of 6.6 at 2 GHz, the least effective dielectric constant of 1.06, and the lowest endurable impact force 0.184 Newton. On the other hand, the spiral inductor with diamond opening has a lowest Q/sub max/ of 4.3, the largest effective dielectric constant of 3.44 and highest endurable impact force 4 Newton. The former is suitable for station telecommunication applications in which the mechanical vibration is not a serious concern, while the latter can be used for mobile telecommunication applications subject to strong mechanical vibrations. Additionally, the conventional on-chip spiral inductor embraced by SiO/sub 2/ with a dielectric constant of 4 was prepared for comparison and found its Q/sub max/ is 3.8 at 1.2 GHz.     

Substrate noise-coupling characterization and efficient suppression in CMOS technology

This brief investigates the substrate noise coupling using S-parameters measurement. Radio frequency domain analysis shows that the noise isolation is strongly dependent on layout geometry, including the parameters such as p-n junction, physical separation distance, guard ring (GR), and deep n-well (DNW). We found that the noise coupling can be efficiently diminished by incorporating GR and DNW structures.     

Sheldon H. White (1928-2005).

Sheldon "Shep" Harold White, one of developmental psychology's most distinguished scholars, died on March 17, 2005, at the age of 76. He is perhaps best remembered for his sharp intellect, generous spirit, good humor, and warm compassion. Shep's principal work lay in three intermeshed areas: children's learning and cognitive development, social programs and policies, and the history of developmental psychology. Shep White is sorely missed by his family and friends, and countless children have unknowingly benefited from his research, scholarship, and contributions to public policy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A novel process for fabricating electrical contact SnO<Subscript>2</Subscript>/Ag composites by reciprocating extrusion

Reciprocating extrusion combined with simple powder compaction was used to produce electrical contact SnO₂/Ag composites from Ag and SnO₂ powders with improved properties. The SnO₂ particles were uniformly dispersed in the Ag matrix after 20 passes of extrusion. The hardness of the composites increased with extrusion passes and leveled off after ten passes, whereas the electrical conductivity decreased slowly after five passes. The variation of the coefficient of thermal expansion with temperature revealed that SnO₂/Ag interface strength increased with extrusion passes and was greatest after 20 passes. The SnO₂/Ag composites with 20 passes showed the best electrical contact properties in which there was no mass loss through mass transfer from cathode to anode during the make-break erosion test at both low and high current conditions. On the other hand, SnO₂/Ag composites with one pass and commercial SnO₂-In₂O₃/Ag specimens had an apparent mass loss under the same condition. Electrical contact composites produced by the present method are promising in electrical contact applications in consideration of cost and performance.     

The control of protein release from poly(DL-lactide co-glycolide) microparticles by variation of the external aqueous phase surfactant in the water-in oil-in water method

A unique feature of p21 that distinguishes it from the other cyclin-dependent kinase (CDK) inhibitors is its ability to associate with the proliferating cell nuclear antigen (PCNA), an auxiliary factor for DNA polymerases delta and epsilon. While it is now well established that inhibition of cyclin/CDK complexes by p21 can result in G1 cell cycle arrest, the consequences of p21/PCNA interaction on cell cycle progression have not yet been determined. Here, we show, using a tetracycline-regulated system, that expression of wild-type p21 in p53-deficient DLD1 human colon cancer cells inhibits DNA synthesis and causes G1 and G2 cell cycle arrest. Similar effects are observed in cells expressing p21CDK-, a mutant impaired in the interaction with CDKs, but not in cells expressing p21PCNA-, a mutant deficient for the interaction with PCNA. Analysis of cells treated with a p21-derived PCNA-binding peptide provides additional evidence that the growth inhibitory effects of p21 and p21CDK result from their ability to bind to PCNA. Our results suggest that p21 might inhibit cell cycle progression by two independent mechanisms, inhibition of cyclin/CDK complexes, and inhibition of PCNA function resulting in both G1 and G2 arrest.     

CD28-independent, TRAF2-dependent costimulation of resting T cells by 4-1BB ligand

4-1BB ligand (4-1BBL) is a member of the tumor necrosis factor (TNF) family expressed on activated antigen-presenting cells. Its receptor, 4-1BB, is a member of the TNF receptor family expressed on activated CD4 and CD8 T cells. We have produced a soluble form of 4-1BBL using the baculovirus expression system. When coimmobilized on plastic with anti-CD3, soluble 4-1BBL induces interleukin (IL)-2 production by resting CD28+ or CD28- T cells, indicating that 4-1BBL can function independently of other cell surface molecules, including CD28, in costimulation of resting T cell activation. At low concentrations of anti-CD3, 4-1BBL is inferior to anti-CD28 in T cell activation. However, when 4-1BB ligand is provided together with strong TCR signals, then 4-1BBL and anti-CD28 are equally potent in stimulation of IL-2 production by resting T cells. We find that TNF receptor-associated factor (TRAF)1 or TRAF2 associate with a glutathione S-transferase-4-1BB cytoplasmic domain fusion protein in vitro. In T cells, we find that association of TRAF1 and TRAF2 with 4-1BB requires 4-1BB cross-linking. In support of a functional role for TRAF2 in 4-1BB signaling, we find that resting T cells isolated from TRAF2-deficient mice or from mice expressing a dominant negative form of TRAF2 fail to augment IL-2 production in response to soluble 4-1BBL. Thus 4-1BB, via the TRAF2 molecule, can provide CD28-independent costimulatory signals to resting T cells.     

MR imaging of the major nerves about the elbow: cadaveric study examining the effect of flexion and extension of the elbow and pronation and supination of the forearm

Magnetic resonance (MR) imaging provides useful information in the evaluation of peripheral nerves. Recent advances in MR imaging allow for detailed depiction of the soft tissue structures of the elbow joint. Three major nerves are present about the elbow. Six cadaveric elbows were imaged to depict the normal anatomy of these nerves and to determine the best plane and position of the elbow for optimal visualization of each nerve. Axial images of the elbow in full extension with the forearm in supination allow identification of all major nerves. Axial images with the elbow in full flexion allow accurate assessment of the cubital tunnel and the ulnar nerve. Axial images of the elbow in full extension with the forearm in pronation are helpful for assessment of the median and radial nerves in the forearm.     

Synthesis and post-annealing effects on the transport properties of thermoelectric oxide (ZnO)mIn2O3 ceramics

The synthesis and transport properties of n-type thermoelectric oxide (ZnO)_mIn₂O₃ (Z_mIO) ceramics prepared by conventional solid-state reaction method have been reported. It is found that the transport properties of Z_mIO ceramics are very sensitive to the post-annealing temperature as well as the zinc content m. The resistivity of Z₅IO annealed at 1400 °C decreases by more than 2 orders of magnitude in comparison with that of Z₅IO annealed at 1200 °C, while the resistivities of Z₆IO compounds annealed at 1250 and 1350 °C are more than 3 orders of magnitude larger than that of Z₆IO annealed at 1300 °C. All the Z_mIO compounds annealed at 1300 °C show electron-type conduction with a lowest resistivity at m = 6. It is suggested that the oxygen defects or vacancies in the InO₂ layers play a major role on the carrier scattering mechanism, and the observed temperature-dependent resistivity for Z₅IO and Z₆IO compounds can be satisfactorily described by the variable-range hopping conduction. Furthermore, it is found that the values of Seebeck coefficient for Z_mIO are also very sensitive to the zinc content m. The dimensionless figure of merit of 0.0045 at 300 K for m = 6 has been obtained.     

Synthesis of Fe3O4 Nanowire Arrays Via Precipitation in Templates and Microwave Hydrothermal Process

Template growth of Fe₃O₄ nanowire arrays via precipitation and subsequent microwave hydrothermal process was investigated. Anodic aluminum oxide and polycarbonate templates were immersed in a ferrous chloride and ferric chloride mixture and the precipitation of Fe₃O₄ took placed by adjusting the solution to pH>9. A microwave hydrothermal process was subsequently performed at 150°C for 30 min in order to further enhance the crystallinity of the Fe₃O₄ nanowires. The length of the nanowires is about 5–20 μm and the diameter is about 220 nm, with perfect surface finishing. The nanowires were polycrystalline cubic spinel structures and composed of nanometer-sized particles, as characterized by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. Magnetic properties in parallel and perpendicular direction were measured using a vibrating sample magnetometer, where the magnetization in the perpendicular direction of the nanowires is higher than that of the parallel direction. Microwave hydrothermal treatment improved the crystallinity and morphology of Fe₃O₄ nanowires and resulted in a much better magnetization than that without microwave hydrothermal treatment.