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The desire for ever-higher drive currents from MOS transistors has forced aggressive scaling of physical gate lengths over the past three decades, with no end in sight. Continued scaling alone […]

The origin of EUVL can be found in a 1988 paper [1]. It proposed that recent advances in 'high' reflectivity soft x-ray mirrors could enable an all-reflective, projection lithography system […]

About every three years, a new DRAM generation requires a new lithography system capable of imaging 3x more pixels, with a substantial improvement in resolution. This results in a 2.5x-3x […]

It is generally agreed that optical lithography will run out of steam once 193-nm technology has reached its full potential. For some, 0.15-micron geometries may be the end of the […]

I remember seeing Glen Tetley ('Transitions,' April) and his company perform Embrace Tiger and Return to Mountain, Pierrot Lunaire, and Mythical Hunters in 1969. Tetley himself danced Pierrot, with Scott [...]

A 6-7month histologic study of vitreous carbon endosteal implants in occlusion was conducted in dogs to determine whether the shape of the implant has adverse effects on supporting tissues. Conical vitreous carbon implants were placed in fresh, second, and third premolar extraction sites, and the sites were allowed to heal for periods of 2 to 8 weeks prior to restoration with cast gold crowns. Gingival tissues healed routinely and showed inflammatory conditions similar to tissues adjacent to teeth, and normal sulculur depths were measured. Bone formation was observed within grooves in the implant surface, providing retention and stabilization; normal bone remodeling appeared to be occurring adjacent to the implant sites. No inflammatory responses, foreign body reactions, or infections were observed. Vitreous carbon appears well suited for applications as an endosteal implant material.

A 6-month histologic study of vitreous carbon dental implants in dogs, without occlusion, has demonstrated that vitreous carbon is well tolerated by oral tissues in both permucosal and subgingival applications. Gingival tissues heal routinely and show the same degrees of irritation adjacent to the implant as tissues adjacent to natural teeth. Alveolar bone forms within grooves in the implant surface, providing mechanical retention, and both hard and soft tissues grow into the texture in the implant surface. The resulting interlocking between tissues and the implant appears to function effectively as a bacterial seal. The newly formed bone within the implant grooves appears to become more dense with time, resulting in a layer of dense bone surrounding the implant. No foreign body responses and no inflammation were observed in tissues adjacent to this implant material, and no degradation of the vitreous carbon implants was detected. A subsequent study of the implant under occlusion in dogs is also being conducted.

Verapamil has been shown to depress the contractility of ischemic myocardium. The present study was designed to determine whether that effect is due to an increase in ischemic injury caused by the drug or whether it might reflect a protective effect. A critical partial occlusion was effected on the left anterior descending coronary artery of 16 open chest foxhounds. A fiberoptic pH probe was implanted in the subendocardium of the ischemic zone, and coronary blood flow was reduced by 79% from a control value of 38 ± 4 ml/min and held constant. Mean coronary perfusion pressure was decreased 48% from its control value of 90 ± 6 mm Hg and remained constant.

Several letters to the editor are presented in response to articles in previous issues including one on the Ravel Piano Concerto in G recordings, one on the reissue of the Georg Solti recording of Richard Wagner's "Das Rheingold," and one about Spanish tenor Placido Domingo.

Low-korganosilicate films are considered essential for meeting the material needs of interconnect dielectric layers in present and future semiconductor devices. These materials, whether deposited by chemical vapor deposition or spin-on processes, are mechanically inferior as compared to undoped silicate glass or fluorine doped silicate glass. The introduction of porosity to further lower the dielectric constant diminishes the mechanical properties even more. For this reason, post-porosity treatments such as E-beam and UV curing have been explored. In this paper, we describe the use of laser spike annealing (LSA) to achieve similar results. Infrared analysis coupled with Rutherford backscattering, forward recoil, and X-ray photoelectron spectroscopy were used to study the effect of varying laser power and dwell time on the structural changes of both a dense and porous organosilicate, indicating removal of hydrogen and some carbon from the samples. These changes were interpreted in terms of oxidative and bond redistribution transformations. As a result of the structural changes, significant increases in Young’s modulus were achieved. Properties such as k, refractive index, film shrinkage, and water contact angle were also correlated with laser power and dwell time. LSA compares favorably with both E-beam and UV curing and three times improvements in modulus without significantly affecting kwere observed.