Abstract:
We encounter electronic devices in our daily lives. We live in an era where we cannot imagine our
lives without these devices; their importance will increase with time. The world of electronics has been revolutionised since the introduction of transistors. Transistors are the basic functional unit of modern day electronic devices and are used in making integrated chips. Thus, it is essential to study transistors.
Mosfet is the most commonly used transistor. Mosfet is usually preferred over other transistors like BJT, etc., for many reasons, including the flexibility to control conductivity across the source and drain.
In 1965, Gordon Moore noticed that the number of transistors on the integrated circuit “chips” doubled every technology generation (about one year then, about 1.5 years now). The number of transistors per chip in each technology generation was doubled by down-scaling the size of transistors. Besides the physical benefits, nano-scale MOSFETs reduce transmit time for carriers due to short channel length, which performs faster-switching operations. There are several other factors advocating nano-scale technologies. Thus, it is essential to delve deeper into nano-scale MOSFETs.
To understand these nano-scale MOSFETs, we need to delve deeper into the ballistic motion of carriers. But before studying the ballistic motion, we have to have a good understanding of the classical model of MOSFET for long channels and have to understand the physics behind the carrier transport, semiconductors, pn junctions, Energy bands, wave nature of electrons (statistical behaviour as a group of carriers) and various other concept-building elements. However, continuous downscaling of the size of MOSFETs also poses multiple limitations. I have decided to study GeSn alloy for this purpose. Germanium provides the highest hole mobility among bulk semiconductors and Sn introduces high electron mobility. Thus, GeSn alloy is ideal. Later in the report, I discussed in detail the reason for choosing this alloy.
