Semiconductors revolution

R. Haitz, F. Kish, J. Tsao, and J. Nelson, Another Semiconductor Revolution This Time It s Lighting , Compound Semiconductor, Vol.6, No.2, p.34-37. 

The second key event was the semiconductor revolution, Silicon rapidly became the essential raw material for new electronic devices. Silicon chemistry grew as it became an integral part in the design and production of these electronic devices, which are housed on a thin chip of silicon. 

As an engineering student, you are undoubtedly aware of the pervasive importance of semiconductors in our 21st century lives. Semiconductor technology is at the heart of the electronics industry. As microprocessors find their way into our cars and appliances, the scope of that industry has never been broader. The rise of the semiconductor is an excellent example of the interplay between the atomic scale view of chemistry and the macroscopic scale thinking of engineering. It is fair to say that the semiconductor revolution could not have taken place without the ingenious development of a host of new materials not found in nature. 

Although the cost of most professional equipment has been going up in recent years, maintenance technicians have seen a buyer s market in test instruments. The semiconductor revolution has done more than given consumers low-cost computers and disposable devices. It has also helped to spawn a broad variety of inexpensive test instruments with impressive measurement capabilities. 

LED due to the direct bandgap of the Ill-nitrides. However, due to the lack of a native substrate for GaN, sapphire or SiC substrates were and are still used. The biggest use of semiconductor-grade SiC is still for LEDs, but now it serves the role as the substrate for the active GaN layer rather than both the substrate and the active layer. Today there are high-freqnency metal-semiconductor-field effect transistors (MES-EETs) offered commercially, as well as an emerging market for Schottky diodes made from SiC. We are still at the beginning of the SiC revolution, however, and the material s full potential has yet to be realized. 

The discovery of semiconductor integrated circuits by Bardeen, Brattain, Shockley, Kilby, and Noyce was a revolution in the micro and nano worlds. The concept of miniaturization and integration has been exploited in many areas with remarkable achievements in computers and information technology. The utility of microchips was also realized by analytical scientists and has been used in chromatography and capillary electrophoresis. In 1990, Manz et al. [1] used microfluidic devices in separation science. Later on, other scientists also worked with these units for separation and identification of various compounds. A proliferation of papers has been reported since 1990 and today a good number of publications are available in the literature on NLC and NCE. We have searched the literature through analytical and chemical abstracts, Medline, Science Finder, and peer reviewed journals and found a few thousand papers on chips but we selected only those papers related to NLC and NCE techniques. Attempts have been made to record the development of microfluidic devices in separation science. The number of papers published in the last decade (1998-2007) is shown in Fig. 10.1, which clearly indicates rapid development in microfluidic devices as analytical tools. About 30 papers were published in 1998 that number has risen to 400 in... 

The communications revolution also relies on a diverse set of CVD technologies. Some components are similar to those used in silicon microelectronics, but many are unique, involving complex epitaxial heterostructures of SiGe or compound semiconductor (e.g., AlGaAs) alloys that are required to yield high frequency (1-100 GHz) device operation. The communication revolution also relies on optoelectronic components, such as solid state diode lasers (another complex heterostructure device), and these devices are often grown by CVD. - Even the fiberoptic cables that transmit the optical component of the communications network are manufactured using a CVD technique to achieve the desired refractive index profile. ... 

The technology itself has advanced tremendously as substantial improvements in capability have led to greatly improved performance with increasingly tight process control. Many semiconductor processes used in manufacturing now have over ten CMP steps within them, this revolution in semiconductor technology has occurred because of demand pull. CMP based processes can be more powerful than those processes without CMP. 

Semiconductor processing—A second electronics revolution Mater. Today 13, 1997. 

At the same time, the coming of the PC revolution saved the American semiconductor industry. No Japanese competitor had any hope of entering the production of microprocessors and operating systems, which was protected by Intel s and Microsoft s economies of scale and scope. So, as the five American leaders were shutting down their memory plants, they were simultaneously building even larger microprocessor plants. 

The invention of the STM was in fact a true revolution in the fields of surface science and microscopy. After extremely high atomic resolution was achieved on clean semiconductor and metal surfaces, further studies were carried on surfaces that were covered with molecules, to observe structural information. 

Metalloids have some chemical and physical properties of metals and other properties of nonmetals. In the periodic table, the metalloids lie along the border between metals and nonmetals. Silicon (Si) is probably the most well-known metalloid. Some metalloids such as silicon, germanium (Ge), and arsenic (As) are semiconductors. A semiconductor is an element that does not conduct electricity as well as a metal, but does conduct slightly better than a nonmetal. The ability of a semiconductor to conduct an electrical current can be increased by adding a small amount of certain other elements. Silicon s semiconducting properties made the computer revolution possible. 

Fig. 10a-c. Different photoelectrochemical reactions involving water on layer type semiconductors, a) sulphate formation on M0S2, b) Ru(2,2 -bipyridine)3]3+/2+ as redox catalyst, c) (Revolution on PtSj... 

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