Microprocessors have found their way in almost every electronic device that is available today. Microprocessors and microcontrollers enable the modern world to produce devices that comprehend the environment and react to situations producing a much desired effect. The operating speed of modern day computers has increased over a thousand times in the past twenty years. Microprocessors, quite different from what we know them as today, were invented in 1971 by a small group of people operating at a very young Silicon Valley Startup named Intel.
Intel 4004 is known to be the first microprocessor that was made commercially available.
Moore’s Law, an interesting observation of the doubling of transistors on a dense IC in nearly two years, has actively allowed microchip vendors to set long term targets when it comes to technology. The microprocessors available to us today have developed complex architectures over time and are now seen to have a handful of engines, termed as cores, to cater to relatively complex functions like graphics handling, floating point arithmetic and memory control.
Microprocessors use a nanometer technology measure to address the smallest cut that can be made on the silicon wafer. This allows smaller transistors to be formed on the substrate adding up to a denser and energy efficient chip.
Apple, in 2018, will presumably employ 7-nanometer chips in their upcoming iPhone models which would help better the power consumption and performance over its predecessor markedly.
As transistors delve into atomic distances, semiconductor lithography poses constraints in future scaling. As the transistor technology improves, it requires less energy to operate efficiently. The threshold voltage is an important characteristic of a transistor. It can be defined as the voltage at which the transistor allows current to pass through. The problem lies in the imperfection of a transistor behaving as a switch as the substantial amount of energy, consumed in a microchip, is due to leakage. The situation worsens as the density of transistors on a chip increases. This puts a grave toll on transistor performance which can only be maintained by increasing the threshold voltage value.
This limiting fact dictates that the upcoming years would preferably continue to increase transistor density but would provide comparatively little improvement in speeds and energy consumption. As a result, the operations performed on the new chips would take, more or less, the same time as the chips used today unless a better architecture is implemented to solve the problem.
Due to such limitations placed on the microprocessors of today, many scientists are now exploring other domains to keep building the performance of microprocessors. Technologies and relatively new domains of science like Carbon Nanotubes, Graphene and magnetic-dependent devices (in nanometers) like MQCA (magnetic quantum dot cellular automata) and spinFETs (spin field effect transistors) have been developed to achieve this improvement. As the principle of operation for these technologies differs from the common CMOS chips, further advancements might require a complete overhaul in microprocessor design and manufacturing. Nevertheless, all such technologies are passing through infancy and would require time and consistent research to finally be introduced to the market.