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This book is designed to provide contemporary readers with an understanding of the emerging high-speed signal integrity issues that are creating roadblocks in digital design. Written by the foremost experts on the subject, it leverages concepts and techniques from non-related fields such as applied physics and microwave engineering and applies them to high-speed digital design -creating the optimal combination between theory and practical applications.

Dry etching of Si is critical in satisfying the demands of the micromachining industry. The micro-electro-mechanical systems (MEMS) community requires etches capable of high aspect ratios, vertical profiles, good feature size control and etch uniformity along with high throughput to satisfy production requirements. Surface technology systems' (STS's) high-density inductively coupled plasma (ICP) etch tool enables a wide range of applications to be realized whilst optimizing the above parameters. Components manufactured from Si using an STS ICP include accelerometers and gyroscopes for military, automotive and domestic applications. STS's advanced silicon etch (ASETM) has also allowed the first generation of MEMS-based optical switches and attenuators to reach the marketplace. In addition, a specialized application for fabricating the next generation photolithography exposure masks has been optimized for 200 mm diameter wafers, to depths of ~750 µm. Where the profile is not critical, etch rates of greater than 8 µm min-1 have been realized to replace previous methods such as wet etching. This is also the case for printer applications. Specialized applications that require etching down to pyrex or oxide often result in the loss of feature size control at the interface; this is an industry wide problem. STS have developed a technique to address this. The rapid progression of the industry has led to development of the STS ICP etch tool, as well as the process.

Estimates of ground‐water velocity, based either on Darcy's law or on the single‐well drift and pumpback tracer method, require prior knowledge of effective porosity. That is, after field data have been collected, the equation for ground‐water velocity, using either method, still contains the two unknowns, velocity and porosity. If the local hydraulic gradient is known and if a drift and pumpback tracer test is conducted at a well whose hydraulic conductivity has been determined, two independent functional relationships between velocity and porosity are established. By treating these functions as nonlinear simultaneous equations, a unique solution for the local velocity and porosity can be obtained.

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In this work, we present experimental results examining the energy distribution of the relatively high ͑Ͼ1 ϫ 10 11 cm −2 ͒ electrically active interface defects which are commonly observed in high-dielectric-constant ͑high-k͒ metal-insulator-silicon systems during high-k process development. This paper extends previous studies on the Si͑100͒/SiO x /HfO 2 system to include a comparative analysis of the density and energy distribution of interface defects for HfO 2 , lanthanum silicate ͑LaSiO x ͒, and Gd 2 O 3 thin films on ͑100͒ orientation silicon formed by a range of deposition techniques. The analysis of the interface defect density across the energy gap, for samples which experience no H 2 /N 2 annealing following the gate stack formation, reveals a peak density ͑ϳ2 ϫ 10 12 cm −2 eV −1 to ϳ1 ϫ 10 13 cm −2 eV −1 ͒ at 0.83-0.92 eV above the silicon valence bandedge for the HfO 2 , LaSiO x , and Gd 2 O 3 thin films on Si͑100͒. The characteristic peak in the interface state density ͑0.83-0.92 eV͒ is obtained for samples where no interface silicon oxide layer is observed from transmission electron microscopy. Analysis suggests silicon dangling bond ͑ P bo ͒ centers as the common origin for the dominant interface defects for the various Si͑100͒/SiO x /high-k/metal gate systems. The results of forming gas ͑H 2 /N 2 ͒ annealing over the temperature range 350-555°C are presented and indicate interface state density reduction, as expected for silicon dangling bond centers. The technological relevance of the results is discussed.

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