Semiconductors fabrication

R Eichinger, H. J. Rath, and H. Schwenke. In Semiconductor Fabrication Technology and Metrology. ASTM STP990. (D. C. Gupta, ed.) American Society for Testing and Materials, 305, 1989. 

A major and growing use of the minor metalloids is in semiconductor fabrication. Germanium, like silicon, exhibits semiconductor properties. Binary compounds between elements of Groups 13 and 15 also act as semiconductors. These 13-15 compounds, such as GaAs and InSb, have the same number of valence electrons as Si or Ge. The energy gap between the valence band and the conduction band of a 13-15 semiconductor can be varied by changing the relative amounts of the two components. This allows the properties of 13-15 semiconductors to be fine-tuned. 

In the field of microelectronics, there is continuing research in developing new materials to be used in semiconductor fabrication. They must be formed as thin films in a controlled, reproducible and uniform manner to be useful in semiconductor manufacturing applications. Depth profiling by AES is used to assess the properties of such films. The samples are sputtered with an argon ion beam and analysis performed using standard sensitivity factors, and it is possible to demonstrate that such films are uniform throughout a depth of, say, 250 nm. 

Since the late 1970s, electroanalytical array sensors have been constructed by methods similar to the well-established semiconductor fabrication processes, which use... 

Guide for Venting of Deflagrations Standard on Explosion Prevention System Standard for the Protection of Semiconductor Fabrication Facilities... 

Semiconductor energy levels, 9 728-730 Semiconductor fabrication, standard dimensional tolerance used in,... 

As mentioned above, the conventional diazonium salts have good optical properties as CEL dyes and negative working sensitizers for the two-layer resist system. However, almost all diazonium salts are stabilized with metal-containing compounds such as zinc chloride, tetrafluoroborate, hexafluoro-antimonate, hexafluoroarsenate, or hexafluorophosphate, which may not be desirable in semiconductor fabrication because of potential device contamination. To alleviate the potential problem, new metal-free materials have been sought for. 

Due to its unique ability to directly image the local structure of a thin object with atomic resolution, HRTEM is an extremely powerful tool for materials research. Metals, ceramics, and semiconductors are some examples of prominent materials of interest. HRTEM imaging used to be a high-end research tool mostly used in academia, but has now become standard for a wide variety of applications from materials science research to defect analysis in industrial semiconductor fabrication lines. 

Researchers at Lehigh University are developing a methanol reforming silicon reactor with a palladium membrane for a hydrogen purification system built using semiconductor fabrication techniques. The device is designed to produce hydrogen for fuel cells for portable electronic devices, such as laptop computers and cell phones. 

We now turn to photoconductive and photodiode detectors, both of which are semiconductor devices. The difference is that in the photoconductive detector there is simply a slab of semiconductor material, normally intrinsic to minimize the detector dark current, though impurity doped materials (such as B doped Ge) can be used for special applications, whereas by contrast, the photodiode detector uses a doped semiconductor fabricated into a p-n junction. 

I. CMP A Unique and Evolving Semiconductor Fabrication Technology—Past, Present, and Future. 1... 

The History and Development of CMP as a Unique Semiconductor Fabrication Technology... 

This topic is well covered by the contributions in this volume. CMP continues to be viewed as a surprisingly unique and flexible semiconductor fabrication technology by virtue of its ability to make manufactureable potential fabrication sequences that are either too cumbersome or too low in yield to be fabricated in any other manner. Using virtually any CMP polisher, a variety of materials of interest to IC fabricators can be planarized. These materials include insulators, semiconductors, interconnect metals, and barrier metallurgies. This means that once a user becomes adept in polishing one kind of material, typically oxide and W at first, other materials of interest and other semiconductor processing sequences become viable. 

Two types of ion source produce high enough brightness (> 106 A/cm2.ster., 20 keV) for them to be considered for semiconductor fabrication applications the field ion source (56) and the liquid metal source (57,58). The field ion source produces relatively small energy spread (<3 eV) and when combined with a short focal length (< 1 cm) electrostatic focusing system should be able to produce beam sizes as small as 10 nm with adequate current (10-11 amp) for laboratory microfabrication experiments. As with field emission electron sources, the field ion source only produces a limited total current and the maximum beam current is limited to about 1 10 amp. 

Gise P, Blanchard R (1998) Modern Semiconductor Fabrication, Englewood Cliffs, New Jersey. 

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