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Sunday, September 6, 2020

#445 Semiconductor materials: properties and applications

Whenever it comes to the selection of semiconductor material for any given semiconductor device application, width of the energy gap (or bandgap) is the first consideration. The reason is rather straightforward - if the material features no naturally occurring energy gap (for instance graphene), then it cannot be used to fabricate devices efficiently performing some mainstream electronic functions such as for instance switching.


Another important characteristic is the type of the bandgap, direct, or indirect with the former allowing superior in terms of efficiency emission of light as compared to the latter. This criterion, though, is less clear-cut now as it used to be because of the success in enforcing light emission from the indirect bandgap silicon. Not very efficient, but still, commercially viable.


Then comes electron mobility which decides on how good of the conductor of electricity given semiconductor is, and also determines speed at which device fabricated using given semiconductor can operate. It is convenient from some device applications point of view to have a material featuring at the same time high mobility of electrons and (relatively) holes. But here again quantum phenomena are blurring the picture because when the ballistic transport takes over, electron mobility is no longer a factor determining device’s speed of operation.


Look for more details regarding device implications of physical characteristics of semiconductor materials in my book “Guide to Semiconductor Engineering”.

Posted by Jerzy Ruzyllo at 10:00 AM | Semiconductors | Link is a personal blog of Jerzy Ruzyllo. He is Distinguished Professor Emeritus in the Department of Electrical Engineering at Penn State University. With over forty years' experience in academic research and teaching in semiconductor engineering he has a unique perspective on the developments in this technical domain and enjoys blogging about it.

This book gives a complete account of semiconductor engineering covering semiconductor properties, semiconductor materials, semiconductor devices and their uses, process technology, fabrication processes, and semiconductor materials and process characterization.

With over 2000 terms defined and explained, Semiconductor Glossary is the most complete reference in the field of semiconductors on the market today.


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