Semiconductors are materials with conductivity between conductors (usually metals) and non-conductors or insulators such as ceramics. Semiconductors may be pure elements, such as silicon or germanium, or compounds such as gallium arsenide or cadmium selenide. In a process called doping, small amounts of impurities are added to pure semiconductors, which cause major changes in the conductivity of the material.

 

Due to their role in the manufacture of electronic devices, semiconductors are an important part of our lives. Imagine life with no electronic devices. There will be no radios, no TVs, no laptops, no video games and no medical testing equipment. Although many electronic devices could be manufactured using vacuum tube technology, developments in semiconductor technology have made electronic devices smaller, faster and more reliable over the last few years. Think about all the encounters you have with electronic devices for a minute. Each of them has important components that have been manufactured with electronic materials.

 

Why do we need semiconductors?

It is the foundation of any electronic system that we take for granted. It is a big industry and many departments of electrical engineering in universities around the world are interested in research aimed at developing new technologies and responsible for events in history. Semiconductors are also so fragile that a single error in the manufacturing process might have ruined all the chips.

 

Companies like Intel also spend billions of dollars on R&D in semiconductor production and design. It's amusing to know how we're taking bits of sand, turning it into silicone, and doping those elements of the periodic table to produce transistors that, in turn, drive the digital era. Also, its amazing that semiconductors are one of the only fields where quantum mechanics can be seen at work.

Why are semiconductors used in electronics? 

The semiconductor block in itself is not very often used in electronics. It becomes useful when doped and used to build a P-N junction. Doping changes the conductivity of the semiconductors in a regulated manner and the junctions make it possible to use them for various purposes, such as rectification and amplification. Before the advent of semiconductor vacuum tubes, which were heavy, expensive and heat dissipated, were used for this purpose.

 

As suitable doped with P and N type impurities, two semiconductor blocks are joined end to end, forming a rectification junction. Present will now flow in one direction and be blocked in the other. This property is used to transform AC signals to DC signals. This can also be done by vacuum diodes with demerits. If the PN and the NP junction are formed inside a semiconductor with an acceptable doping profile, the bipolar junction transistor may act as an amplifier.

 

One of the most important advantages of semiconductors is that they can be oxidized to form a high dielectric layer over a semiconductor which can act as a protective layer, mask and gate oxide in MOS transistors. MOS are the basic building blocks of today's digital electronics.