Search

A process to achieve 12 nm half-pitch interconnect structures in ultralow-k interlayer dielectric (ILD) is realized using standard 193 nm lithography. An optimized pattern transfer that minimizes unwanted distortion of ILD features is followed by copper fill. Electrical measurements that validate functionality of the drawn structures are presented.

The patterning of a 34 nm metal pitch interconnect was realized using a spacer-based pitch quartering scheme. The pattern is transferred into an ultralow-k ILD using a process that avoids ILD buckling and structure collapse. Resulting features were metallized with copper, and electrically characterized. Measurement results show expected trends with drawn dimensions.

For tight pitch patterning with sub-wavelength mask features, simulations and wafer data show that many mask stacks that provide superior image contrast, can provide inferior MEEF performance. For example, 6% MoSi EPSM is found to have higher MEEF than binary masks despite having better contrast and exposure latitude when equal lines and spaces on the mask are used to pattern equal lines and spaces on the wafer. Likewise, the deposition of SiO2 on-top of the chrome surface of a binary mask improves contrast but degrades MEEF compared to a binary mask. When contrast is varied by mask stack or by print bias, MEEF is poorly correlated with contrast and often increases with increasing contrast. The optimal print bias for exposure latitude is significantly different than the optimum print bias for MEEF. MEEF, on the other hand, is highly correlated with the difference between maximum and minimum intensity when one varies mask stack, print bias and illumination. Analytical MEEF equations are derived that support this strong relationship between MEEF and the difference between maximum and minimum intensity.

The primary purpose of surfactants used in stimulating sandstone reservoirs is to reduce surface tension, contact angle and leakoff control. However, many of these chemicals adsorb rapidly within the first few inches of the sandstone formations, reducing their effectiveness in deeper penetration. This phenomenon causes surfactants to adsorb or plate-out reducing their effectiveness in post fracturing fluid recovery. This study describes experimental and field case studies of various surfactants used in the oilfield. Several different surfactants including a nonionic ethoxylated linear alcohol, nonyl phenol ethoxylate, an amphoteric, a cationic and a microemulsion system were investigated to determine their adsorption properties when injected into a laboratory sand packed column. A laboratory simulated comparison study of commonly used surfactants and microemulsion was used to identify their leakoff and water recovery properties from gas wells. Field data collected from Bradford, Balltown and Speechley sandstone formations confirmed experimental sand packed column and core flow investigations. Reservoirs treated with microemulsion fluids demonstrate exceptional water recoveries when compared with conventional surfactant treatments. Wellhead pressures, flowing pressures and production data were collected and evaluated using a production simulator to show effective fracture lengths, damage surrounding the fractures and drainage areas with various fluid systems. These investigations and presented case studies can be used to minimize formation damage.

Ever since the introduction of friction brakes in vehicles, brake system designers have been striving to improve braking performance. To meet this growing demand for better brakes, lining manufacturers have evaluated numerous additives in their material formulations. These additives provide several different technical properties, the foremost being safety-related features such as frictional stability and resistance to fading. In more recent years, brake noise has become important with the elimination of asbestos fibers in linings, and there is now also a need for a higher frictional coefficient to offset increases in overall vehicle weight. Prolonging the service life of brake components, reducing pad wear, and minimizing rotor wear caused by DTV (Differential Thickness Variation) are other issues that face lining manufacturers. To address all these technical requirements, brake material formulations have become so considerably more complex that increased usage of additives is required. Common additives used in earlier brake lining formulations were metal powders and metal sulfides. Later it was found that synergistic mixtures of various solids actually improved the tribological properties of lining materials over those using a single solid additive. More recently, considerable work has been done in improving the frictional requirements of some additives by changing their surface properties. As a result, current frictional composites use a complex (and usually proprietary) package of additives to meet the needs of modern friction brakes. A discussion of various additives and their contribution to the development and performance of friction brake materials are presented in this paper.

Contrary to known art, we have discovered that lubricated tin-silver connectors have better electrical performance and are more reliable than lubricated silver-silver connectors under high-current and high-vibration conditions. The antifretting lubricant, that enhances the performance and reliability of the tin-silver connectors, is a grease consisting of a hydrocarbon oil in a nano-sized silica-particle base. Focused ion beam and scanning electron microscopy were used to understand the contact degradation mechanism. The superior electrical performance and reliability of the lubricated tin-silver connectors is due to a mechanism that replaces the tin plating from the contact surface with a coating of silver. The removal of the tin plating may be due to wear and the replacement by the silver coating may be due to an electrochemical displacement reaction.

The demand for more powerful internal combustion engines with lower weight, reduced fuel consumption, and favorable environmental properties has led to engine piston designs having lower weight, reduced thermal expansion, and good thermal conductivity. These improvements were needed without sacrificing high thermal strength, reduced operating friction, and increased wear resistance. The need for reduced frictional properties resulted in pistons with shorter skirt lengths, which led to a reduction in effective hydrodynamic surface area perpendicular to the pin bore. At the same time, complex cold start cycles and fuel injection systems were developed that brought enriched fuel mixtures into the engine, causing a dramatic reduction in the viscosity of the lubricant film and thereby its capabilities to protect the sliding surfaces from wear. These higher mechanical stresses on the piston combined with the reduced lubricating ability of the oil film led to increased friction and wear rates, which often resulted in decreased customer satisfaction due to high noise (i.e., piston “slap”) or complete engine failure. To counteract these tribological problems, a variety of piston coatings were developed, but the composition of these coatings often brought a new set of environmental concerns, e.g., the use of heavy metals. The current solution for this problem is to utilize Anti-friction Coatings (AFC’s) on specific areas of the piston. These coatings are based on solid lubricant technology combined with that of high performance resins. The coatings are resistant to fuels and engine oils over the normal operating temperature range of the engine. They also provide a long-term lubricant coating with exceptional capability to handle intermittent excursions outside an engine’s normal duty cycle.Copyright © 2005 by ASME

P-type wafers with oxygen concentration in two ranges near 30 ppma and 33 ppma, respectively, were processed through key thermal cycles. These processes were designed to denude the surface of oxygen, begin nucleation, and precipitate a portion of the oxygen in the bulk for intrinsic gettering. The samples were evaluated using nondestructive optical production profiling (OPP), and the results compared with surface photovoltage (SPV) measurements and cleave-and-etch inspection. The denuded zone depth (DZ) and bulk microdefect density (BMD) measured by OPP gave reasonable correlation with the diffusion lengths determined by SPV. The OPP data also showed the same general trends as the cleave- and-etch data. The shallower DZ and higher BMD reported by OPP in contrast to cleave-and-etch, however, are presumably due to the greater sensitivity of OPP to small defects.

This guide reviews tests, standards, and guidelines in the characterization of dielectric liquid/solid systems for voltage and thermal endurance.

Based on many research investigations and much practical experience, it is well established that the performance capabilities of organic insulating oils are impaired by the presence of contaminants, such as water.1 Recent proposals to use silicone fluids as insulating oils have raised many questions about the effect of contaminants on the electrical properties of these materials.

In his 1971 Whitehead Memorial Lecture,1 Hyde discussed the versatility of silicone fluids, resins, and elastomers with emphasis on the potential of these materials in new insulation systems.

Polydimethylsiloxanes fluids, by virtue of their inorganic, siloxane backbone rapidly form solid bridges on breakdown which effectively extinguish any arcs. If this solid material is continuously removed from the electrode gap, an arc can be sustained, in which case, the “arc power” and volume of gas evolved per unit time are dependent upon molecular structure, molecular weight, and molecular weight distribution of the fluid. Judicious blending of these controllable variables should lead to a silicone insulating fluid having optimum characteristics.