Semiconductors: Maintaining Quality using Semiconductor Inspection Tools
Electronic devices are now considered household items for everyone. Computers, mobile phones, and televisions are just few examples of electronic devices that almost all people have. What are these devices made of? How are they able to function the way they do?
What are Semiconductors?
All electronic and electrical devices are composed of circuits that are designed in such a way that the device will do its purpose. Simple circuits consist of small components such as resistors, capacitors, and transistors. These components have different structures and functionalities, yet they all belong to the same family – that of the semiconductors.
Semiconductors can be considered one of the building blocks of an electronic unit. These are solid materials that exhibit properties of both conductors and insulators; hence, the prefix “semi.” Though semiconductors are like conductors and insulators, their properties are more like those of insulators.
The property that differentiates an insulator from a conductor is the wide band gap to prevent electrons from crossing the gap. Semiconductors also have wide band gap, just a little narrower than insulators. A semiconductor will exhibit the property of a conductor when the electrons in the valence band leaps over the band gap to the conduction band. How is this possible?
Semiconductors change from being an insulator when temperature and other external factors are applied to them. Change in temperature excites the electrons and gives them enough energy to move from one band to the other. Moreover, semiconductors also have some impurities relative to insulators. These impurities allow some electrons of a semiconductor to have more energy than that of an insulator.
Addition of impurities to semiconductors is done through the process called doping. Dopants are introduced to different parts of a semiconductor. The amount of dopants to be added and the region in the semiconductor where they are introduced depend on the intended function of the semiconductor. Doping should be done evenly and as per the design specifications for the semiconductor to work as expected.
Why Inspect Semiconductors?
Any kind of process is susceptible to flaws and mistakes down the line. This is true whether the process is activated by machines and industrial equipments or manually controlled by humans. Producing semiconductors is not an exception, especially since the process involves different kinds of variables.
In the process of producing semiconductors, doping is included. Doping is a variable process because the region in the semiconductor where it should be done is not the same for all kinds of semiconductors. The same goes with the amount of dopant. In cases when the right amount of dopant is not met or when doping is not evenly done, the semiconductor will not perform its designated function.
In this light, semiconductors need to undergo careful inspection before they get out of the production line. In fact, it is more efficient to inspect semiconductors in every stage of the manufacturing process. This will ensure that the outputs from each process are meeting the requirements of the design.
Tools to Inspect Semiconductors
There are different kinds of semiconductor inspection tools that are used by semiconductor companies to ensure the integrity of their products. As technology requirements continue to advance, semiconductor inspection tools are also getting better and better to address the high demands.
There are huge semiconductor inspection tools, mostly from well-known brands in the industry. An example of this tool is Hitachi’s IS-2700. It is capable of detecting defects on wafers that are patterned or not. Another model Hitachi has is its LS-6700 which is for unpatterned wafers. These semiconductor inspection tools can detect scratches, chips, and foreign particles in semiconductor sample.
Semiconductors can also be examined through the use of an inspection microscope. Inspection microscopes are like normal microscopes that can be seen in Biology classes, except that inspection microscopes for semiconductors have more advanced features. An inspection microscope can magnify a semiconductor sample in great detail to detect flaws.
Inspection microscopes can also be used for studying the properties of a semiconductor especially the smaller ones which are more intended for personal use. Industrial inspection microscopes can come in large and bulky sizes to accommodate the amount of semiconductors to be examined at a time. An inspection microscope used in the production line are also controlled by its own computer to work automatically at a fast pace.
One example of a semiconductor inspection microscope is the Olympus MX61 which is an easy-to-use inspection microscope and can detect minute scratches in a semiconductor. There are different models available and different other manufacturers of semiconductor inspection microscopes. They mostly have similar purposes and may just differ in the process of observation.
Semiconductors, indeed, need to be perfect and to be working as designed since they are integral components of all electronic and electrical devices there is. In order to maintain their integrity and quality, semiconductor inspection tools are important for these components to function as they should.
For more information, please visit inspection-microscope.com.
