Silicon, microelectronic circuits

As part of the manufacture of microelectronic circuits, silicon wafers are partially coated with a 5,400-A film of a polymerized organic film called a photoresist. The density of this polymer is 0.96 g/cm. After the wafers are etched, this photoresist must be removed. To do so, the wafers are placed in groups of twenty in an inert boat, which in turn is immersed in strong organic solvent. The solubility of the photoresist in the solvent is 2.23 10 g/cm. If the photoresist dissolves in 10 minutes, what is its mass transfer coefficient (S. Balloge) Answer 4 10 cm/sec. 

Examples are the deposition of polycrystalline silicon coatings in microelectronic circuit fabrication by reactions such as the decomposition of silane,... 

In 1990, Westinghouse engineers reported the production of the purest crystal of silicon ever made—namely, four times purer than previously reported material. The crystal also is significantly larger, adding to its practicality in the manufacture of microelectronic circuits and devices. 

By opening this book, you have already decided that you need to know more about chemistry. Perhaps you want to learn how medicines are made, how fertilizers and pesticides work, how living organisms function, how new high-temperature ceramics are used in space vehicles, or how microelectronic circuits are etched onto silicon chips. How do you approach chemistry ... 

The deposition of polycrystalline silicon in microelectronic circuit fabrication (SiH4 =>Si + 2H2) or the deposition of hardTiC films on machine tool surfaces (TiCl4 + CH4 => HC + 4HC1). 

Silicon dioxide is the most widely used ceramic material in the semiconductor industry, and the majority of Si02 deposits in microelectronic circuits are formed by CVD. Silica layers are used as diffusion sources, intermetallic dielectrics, and dopant and etch barriers in the microelectronics industry. CVD of Si02 is also commonly used in manufacturing energy-efficient glass windows, surface coatings for fiber optics, and micromechanical applications. ... 

Due to their small feature sizes, microelectronic circuits need protection from environmental hazards such as mechanical damage and adverse chemical influences from moisture and contaminants. Several approaches are currently in use, for example, hermetic encapsulation of the device in sealed metal or ceramic enclosures, application of soft silicone gels as a cover over integrated circuitry, and encapsulation by transfer molding, which is the topic of this report. Both silicone resins and epoxy resins are used for this purpose. As the quality and performance of the epoxy encapsulants improved, the need for the generally more expensive silicone resins diminished. The present work is exclusively devoted to epoxy transfer molding compounds. 

An example of recent EX>w Coming Corporation studies of this type has been given by Gentle and Baney. They describe a new concept in corrosion protection based on silica/silicone nanocomposite Aims. Thin films of a silsesquioxane material are applied to a substrate such as aluminum or a microelectronic circuit surface by spin or dip coating... 

Nanotechnology and molecular electronics are progressing rapidly. As semiconductor devices approach their physical limits, researchers are trying to find ways to decrease the size of microelectronic circuits. Thus, cylindrical micelles composed of a ferrocenylsilane-siloxane block copolymer assemble on a silicon surface to form linear features. The micelle lines can then be transformed into a pattern of ceramic nanolines and create conjugated polymer nanowires by controlled chain polymerization. The micelle nanostructures can be converted into magnetic ceramic nanopatterns. It is possible that these lines will display magnetic, conductive and semiconductive properties. 

In the 1990s photolithography and micromachining in silicon were the most popular microfabrication techniques, particularly for integration of microelectronics circuits and MEMS, especially due to silicon s well-known properties. Additionally, glass has also been widely reported because of its biocompatibility, resistance to some... 

Silicon shows a rich variety of chemical properties and it lies at the heart of much modern technology/ Indeed, it ranges from such bulk commodities as concrete, clays and ceramics, through more chemically modified systems such as soluble silicates, glasses and glazes to the recent industries based on silicone polymers and solid-state electronics devices. The refined technology of ultrapure silicon itself is perhaps the most elegant example of the close relation between chemistry and solid-state physics and has led to numerous developments such as the transistor, printed circuits and microelectronics (p. 332). 

While over the last 40 years microelectronic integrated circuits based predominantly on silicon technology have made possible our current capabilities in everything from computers and phones to appliances and toys, even greater opportunities would exist if the circuits could be made more lightweight,... 

Silicon hydrides, in growing amorphous silicon, 22 129-131 Silicon integrated circuits, 19 167 Siliconized coatings, 10 108 Silicon-killed free-machining steels, 24 424 Silicon lattice, 23 35 Silicon-manganese-zirconium, 26 638 Silicon microelectronics, sensor sensitivity and, 22 269... 

In the last case, the use of standard silicon microelectronics technology allow the possibility for integration of optical, fluidics and electrical functions on a single optical sensing circuit leading to a complete lab-on-a-chip technological solution. With this sensor a detection limit in the femtomole range is achievable in a direct format. 

It may be considered a fortunate coincidence that this book is published at the time of the introduction of copper interconnection technology in the microelectronics industry. In 1998 the major electronic manufacturers of integrated circuits (ICs) are switching from aluminum conductors produced by physical methods (evaporation) to copper conductors manufactured by electrochemical methods (electrodeposition). This revolutionary change from physical to electrochemical techniques in the production of microconductors on silicon is bound to generate an increased interest and an urgent need for familiarity with the fundamentals of electrochemical deposition. This book should be of great help in this crucial time. 

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