How do Semiconductors Contribute to the Development of Microprocessors and Microcontrollers?

 What are Microprocessors and Microcontrollers?

Microprocessors and microcontrollers are essential components of an embedded system. These are single-chip processors that accelerate the computing processes in a cost-effective manner. A microcontroller is an integrated circuit (IC) containing a small memory, a microprocessor, a timer, and other components integrated into a single chip. Hence, it is referred to as a computer-on-a-chip.

The microcontroller is used for electronic automation in devices such as consumer electronic products, medical instruments, and process-control instruments. On the other hand, a microprocessor is a computing device’s central processing unit that takes inputs from preset instructions and processes the data in a computing device.

Although the functionalities of the microcontroller and microprocessor are similar, the key difference is that microcontrollers have internal computing peripherals, whereas microprocessors require an external periphery.

The application of microcontrollers is ideal in embedded systems because they can work on a single dedicated program, and microprocessors can be applied in complex computing applications.

Semiconductor Components in Microprocessors and Microcontrollers

Following are the crucial semiconductor-based components that led to the development of more efficient microprocessors and microcontrollers:

1. Resistor: A resistor built on a semiconducting wafer helps limit the flow of electric current through a circuit by dissipating energy in the form of heat. In ICs containing microprocessors and microcontrollers, resistors regulate the electricity and voltage. Common types of resistors built on semiconducting wafers include ion-implanted,  diffused, thin-film, and polysilicon resistors.

2. Transistors: These are semiconductor devices used to switch or amplify electrical signals. These devices are made from semiconductors such as germanium and silicon and are used as gates that function as switches in ICs. A computer chip may contain millions of transistors that can be individually switched on and off. Although transistors may not independently enhance computation speed, improvements in transistor technology and the development of faster transistors facilitate faster computation. The most commonly used transistors are metal–oxide–semiconductor (MOS) transistors. The MOS transistors have a wall of p-type substrate sandwiched between two regions of n-type substrates. Recently, a new generation of transistors called multigate transistors, has emerged, which has significantly enhanced the performance of a microprocessor and thus fast computing.

3. Capacitors: Semiconductor capacitors are nanoscale in size and fabricated on ICs. These capacitors are prepared by depositing oxide layers in sandwich patterns between semiconductor wafers. Capacitors in ICs of microprocessors and microcontrollers help store electrical current.

4. Diodes: A semiconductor diode has a dual-layered structure with a P-type semiconductor on one side and an N-type semiconductor on the other side and forms a central PN junction. This junction allows one-way streets for the conduction of electricity and blocks the conduction in the reverse direction. This type of diode is known as a rectifier.

Types of Semiconductors Used in Microprocessors and Microcontrollers

Pure germanium and silicon do not conduct electricity in their crystal forms, even at high voltages, owing to the tightly held electrons. By introducing a very small amount of phosphorus or arsenic as impurities, these materials can be transformed into semiconducting materials.

If the impurities in the semiconductors produce surplus electrons, they form n-type semiconductors; if the impurity creates a deficiency of electrons, such as boron impurities, they form p-type semiconductors.

Semiconductor materials such as doped germanium and silicon are used in the development of transistors, ICs, and diodes that form an integral part of microcontrollers and microprocessors.

Although germanium is not often used in modern transistors, its exclusive properties make it a good fit for photovoltaic devices. Gallium, when combined with arsenide and phosphide, is used as a semiconducting material in light-emitting diodes.

Advantages of Integrating Semiconductors in Electronic Components

• Semiconductor-based components do not require additional heat to emit electrons, hence they consume low power.

• Semiconductor materials help meet the demand for miniaturization of electronic and computational devices without compromising on performance.

• Semiconducting materials can withstand a wide range of temperatures and other environmental conditions.

Conclusion

Overall, semiconducting materials play a crucial role in the development of microcontrollers and microprocessors, which are critical components in the automation of electronic devices. This unique electrical conduction property makes them a good fit for applications in electronic and computing devices.

Transistors, diodes, and ICs that form the core of microcontrollers and microprocessors have been developed from semiconducting materials such as doped germanium, silicon, and gallium. This material offers advantages, including low energy consumption, enabling the production of high-performance compact devices with the ability to withstand a wide range of temperatures.

Thus, the integration of semiconducting materials into microcontrollers and microprocessors has led to the advancement of the electronics industry, with several advantages.

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References and Further Reading 

Microcontroller Types and Applications, [Online] Available at

https://www.electronicshub.org/microcontrollers (Accessed on 18 June 2023).

ESSCI-CMOS, [Online] Available at https://www.essc-india.org/semicon/cmos.php    (Accessed on 18 June 2023).

Semiconductor Materials, [Online] Available at https://learnabout-electronics.org/Semiconductors/semiconductors_02.php  (Accessed on 18 June 2023).

Microcontroller vs Microprocessor, [Online] Available at

https://www.totalphase.com/blog/2019/12/microcontroller-vs-microprocessor-what-are-the-differences  (Accessed on 18 June 2023).

Microprocessor vs Microcontroller, [Online] Available at

https://www.javatpoint.com/microprocessor-vs-microcontroller  (Accessed on 18 June 2023).

What are the advantages and disadvantages of semiconductor devices? [Online]

Available at https://www.csfusion.org/faq/what-are-the-advantages-and-disadvantages-of-semiconductor-devices/  (Accessed on 18 June 2023).

Diodes, Transistors and FETs , [Online] Available at

https://www.renesas.com/us/en/support/engineer-school/electronic-circuits-02-diodes-transistors-fets (Accessed on 18 June 2023).

Furber, S. (2017). Microprocessors: the engines of the digital age. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 473(2199).  https://doi.org/10.1098/rspa.2016.0893    

Ferain, I., Colinge, C. A., & Colinge, J. P. (2011). Multigate transistors as the future of classical metal–oxide–semiconductor field-effect transistors. Nature, 479(7373), 310-316.  https://doi.org/10.1038/nature10676