Silicon microelectronics applications

The handbook by Pierson contains a very useful discussion of specific materials and CVD processes, as does the book by Morosanu. The books by Hitchman and Jensen, and by Sherman, concentrate more on silicon microelectronics applications, while the books by Stringfellow and by Jones and O Brien concentrate on compound semiconductor applications. The book by Kodas and Hampden-Smith and the series of proceedings volumes, represented by Sandhu et al. ° focus on CVD of metals. A separate series of books on CVD are the proceedings of the International Conferences on CVD held every two to three years since circa 1967, primarily sponsored by the Electrochemical Society. These provide useful snapshots of the field at various times, are a few of the more recent volumes in this series. Books by Vossen and Kern " and Smith,cover CVD as parts of their larger treatments of thin film deposition. 

Layers Typical materials for which CMP processes originally have been developed for microelectronic applications include various types of silicon dioxide such as thermal oxide, TEOS, HDP, BPSG, and other B- or P-doped oxide films. These films are used for various isolation purposes including interlevel dielectric (ILD), intermetal dielectric (IMD), or shallow trench isolation (STI). In addition, n- or p-doped poly-Si, which is a semiconducting material used as capacitor electrode material for DRAMS or gate electrode for MOS applications (CMOS as well as power MOS devices), also has to be polished. Metals for which CMP processes have emerged over the last 10-15 years are W for vertical interconnects (vias) and most importantly Cu as a low-resistivity replacement for aluminum interconnects, employed in the damascene or dual-damascene processing scheme. Other metals that are required for future nonvolatile memories are noble metals like Pt or Ir for which CMP processes have been explored. 

As examples of new, fast-growing applications of reactive silicones, polycarbonate headlight lens coatings [3] and microelectronics applications can be cited. 

The metal platinum (Pt) is not used in modern microelectronic CMOS applications. As an impurity in silicon, platinum possesses electronic states located close to the middle of the bandgap. It exhibits a high diffusion coefficient and large capture cross sections for minority carriers. Therefore, the presence of platinum would severely change the CMOS transistor characteristics and is not allowed inside a silicon microelectronics fab. 

In this contribution, we discussed the materials used as thin films on silicon for sensors in automotive technology. Most of these materials are also used in silicon microelectronics however, due to the different applications, other material properties are relevant for micromechanics. Moreover, some special CMOS-incompatible metals such as platinum and gold are used in, for example, thermal sensors, due to the excellent thermal behavior of their electrical characteristics. 

In spite of the repeated recognition of fullerene-like polymorphs [23-25] it has so far been impossible to isolate them in amounts comparable to those obtained for Ceo and C70. There are only a few studies devoted to the fullerene-like structures, based on elements distinct from carbon or silicon [26-28]. The majority of investigations related to non-carbon clusters has been performed on silicon systems, perhaps because of silicon s applications in the microelectronic industry. 

Spin-On Glass. In microelectronic applications, films of silicon dioxide are deposited on silicon substrates by the application of a partially hydrolyzed solution of tetraethoxysilane or methyltriethoxysilane (59,60). A product based on this technology is marketed under the name Accuspin by AlliedSignal. 

SiC-precursor processing can be subdivided into gas (chemical vapor deposition, CVD) and condensed phase methods. CVD, because of microelectronic applications, has spawned an entire field. It will be discussed here only very briefly. We will focus more intensively on the use of silicon-containing organometaUic precursors as condensed phase sources of ceramic materials. 

Abstract This chapter discusses the use of porous silicon (PSi) for gas sensors. It is of great importance to develop efficient and economically viable gas sensors for different applications. PSi can be nsed as an alternative material for gas sensors, operating at a relatively low temperature, including room temperatnre.The interest in this material is mainly due to its extremely high surface-to-volume ratio, the ease of its formation and its compatibility with modem silicon microelectronics fabrication technologies. A large variety of different sensors made of PSi have been manufactured in recent years, and achievements in this field are reported in this chapter. 

SILICON NITRIDE FOR MICROELECTRONIC APPLICATIONS, PART II APPLICATIONS... 

Defforge T, Coudron L, Menard O, Grimal V, Gautier G, Tran-Van F (2013) Copper electrodeposition into macroporous silicon arrays for through silicon via applications. Microelectron Eng 106 160-163... 

Bomchil G, Halimaoui A, Herino R (1989) Porous silicon the material and its applications in silicon-on-insulator technologies. Appl Surf Sci 41(42) 604-613 Bondarenko VP, Yakovtseva VA (1997) Microelectronic applications of porous silicon. In Chapter 12.1 of properties of porous silicon. Inspec Public.IEE, London Canham (1997) Biomedical applications of porous silicon. In Chapter 12.5 of properties of porous silicon. Inspec Public.IEE, London... 

BPO glass-ceramics are also characterized by a low dielectric constant between 3.8 and 4.5. As a result, the material is suitable for microelectronic applications, where circuit speed is inversely related to the square root of the dielectric constant. Since phosphate-based glass-ceramics are known to exhibit a coefficient of thermal expansion exceeding 100 x 10 K , this coefficient had to be lowered before the material could be used for microelectronic packaging of silicon circuitry. This objective was fulfilled using Si02-rich glass-ceramics, for example, with composition 1 in Table 2-24. A coefficient of thermal expansion of almost 40 x 10" (20°C-300°C) was... 

A specialized type of Li-ion battery developed for semi-conductor and printed circuit board (PCB) applications are thin-film, solid-state devices. These batteries which employ ceramic negative, solid electrolyte and positive electrode materials, can sustain high temperatures (250°C), and can be fabricated by high volume manufacturing techniques on silicon wafers which are viable as on-chip or on-board power sources for microelectronics. Batteries of this type can be very small, 0.04 cm x 0.04 cm x 2.0 fjm. For microelectronics applications, all components must survive solder re-flow conditions, nominally 250°C in air or nitrogen for 10 minutes. Cells with liquid or polymer electrolytes cannot sustain these conditions because of the volatility or thermal stability of organic components. Further, cells that employ lithium metal also fail as solder re-flow conditions exceed the melting point of lithium (180.5°C). 

One way of providing an overview of much of the foregoing material is to consider measurements of displacements near a crack front. It will also provide some points to ponder. A method that the author has used successfully is crack opening interferometry. This requires that at least one of the components of the bonded joint under consideration is transparent to the wavelength of the radiation being used. At first, especially considering the visible spectrum, this may seem to be rather restrictive. However, infrared opens up many practical microelectronics applications due to silicon s transparency to it. The technique also requires that the crack surfaces be quite planar. This condition is not always met by eraeks in monolithic materials, but interfacial or sub-interfacial cracks often meet the planarity requirements. 

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