Comparing IC Chip Materials: GaAs vs. Silicon vs. SiGe

What are IC chips made of? As long as you intend to buy semiconductor chips for your projects, this is a question that you are likely to ask yourself.  Given the importance of IC chips in electrical devices, it is impossible to ignore the materials that they are made of. After all, the material will determine several aspects of the final product. For example, do you know the material of the IC will affect its reliability?

The focus of this article is on three main materials namely gallium arsenide (GaAs), Silicon, and silicon germanium (SiGe). So, how do these materials compare, and which one should I choose? Well, we have the answer to this question. In this article, we are going to compare Silicon, GaAs, and SiGe IC chip materials. We will look at several areas and features of these materials. In the end, you will be in a perfect position to choose the right semiconductor material that will be suitable for your application.

Overview of GaAs

As the name suggests, this is a semiconductor compound that comprises Gallium (Ga) and arsenic  (As) elements. This combination gives it desirable properties to serve as a perfect material for semiconductor chips.

GaAs tend to have high electron mobility. Comparatively, the mobility is way higher than that of silicon. This means that it supports the fast movement of electrons. In case you are building an application in which the speed of electrons is of the essence, then GaAs should be at the top of the list. In other words, they tend to support high-frequency applications.

GaAs tend to have low noise. It has high immunity to electric noise that can interfere with the flow of electrons.  Radiofrequency is the most common noise that affects most semiconductor chips. Minimum noise translates to high accuracy and better performance.

Overview of Silicon

Silicon has been the main material for making semiconductor chips for many years. It has made it possible to explore the limits of semiconductor chips. This is possible because silicon is packed with unique features that make it an ideal material for IC chips.  With an atomic number of 14, Silicon is the second most abundant element that is found on the earth’s crust. It is a metalloid element meaning that it has the properties of metals and non-metals. These properties are what make it a perfect material for IC chips and other electronic applications. It is the foundation of modern electronics thanks to all these properties.

Silicon material has made it possible for manufacturers to develop high-performance electronic devices and applications. It is also easy to fabricate silicon into different products that can be easily transformed into IC chips. You don’t have to worry about the size of the circuit as the material can be fabricated to fit into the circuit.

Overview of Silicon germanium (SiGe)

SiGe or silicon-germanium is a compound that comprises silicon and germanium. It is a popular compound that is used for making semiconductor materials for integrated circuits. It has numerous desirable electrical properties that make it ideal for manufacturing integrated circuits. Germanium and silicon atoms are combined in defined proportions to ensure that the final product has the desired electrical properties.

Comparative analysis of GaAs, Si, and SiGe

Let’s now do a comprehensive comparison of these three materials that are used for making integrated circuits.

 Performance comparison

Which of the three materials is a better performer? GaAs is known for having an extremely high electron mobility. It has the highest of the three materials.  This implies that it can support high frequency. In case you are building an application where performance is of the essence, this may be the right material for the IC. Furthermore, GaAs have a direct bandgap, a feature that makes it an ideal material for applications that rely on light energy.

While Silicon delivers moderate performance, SiGe tends to combine the best features of the two elements. It is highly stable and can still deliver satisfactory results when used for making integrated circuits. It can still support high frequency and speed. 

Electrical properties

 Before you choose any of these materials, you should consider their electrical properties. This will help you know whether they are compatible with your application. As we have mentioned GaAs have high electron mobility. It supports the rapid movement of electrons. Pure silicon has low conductivity and tends to go up depending on the temperature. Silicon germanium has a lower band gap than silicon, it has a higher electrical conductivity.  It also has higher movement of electronics than pure silicon. 

Thermal conductivity

Silicon has a higher thermal conductivity than both GaAs and SiGe. This means that it can easily conduct heat.  This also implies that major temperature changes are likely to affect the electrical performance of silicon, more than  GaAs and SiGe. Temperature is among the reasons why the other two materials are considered alternatives to silicon.

Physical properties

GaAs is the heaviest semiconductor material of the three. It is also the densest. Silicon is the lightest of the three materials.

Comparing gallium arsenide  with silicon

This table gives a complete comparison of GaAs Silicon and SiGe materials for semiconductor chips.

How to  differentiate Si, SiGe, and GaAs

Let’s say you are at the point of purchasing semiconductor chips. How can I tell the differences between these three materials?

The most basic way is by confirming the appearance of these materials. If you are careful enough, you should be able to notice physical differences in terms of their appearance.  For instance, silicon is gray and looks like a typical metal. While GaAs is also gray, it has some silver crystalline appearance on the surface.

Another way of differentiating the three semiconductor materials is by conducting in-depth tests and analyses. Here, you will have to use X-ray technology to analyze the material. Electron microscopy is another technique that you can use to conduct the testing.  Since these three materials have different structural properties, these technologies will help you unearth the differences.

However, advanced testing techniques should be conducted by IC suppliers and distributors. They have the right tools and equipment for doing this job. So, when buying an IC chip, it is important to confirm with the distributor the results of the tests and analyses that they have conducted on the materials.

Why is Silicon still the leading IC chip material?

 Despite the rising popularity of GaAs and SiGe, Silicon remains the leading material for semiconductor chips. Most IC manufacturers are still choosing Silicon even though they can easily choose alternative materials. What is the reason behind the popularity of Silicon?

First, Silicon is easily available. The element can be extracted in its natural form and be used for the manufacturing of integrated circuits. Furthermore, there are easier ways of refining silicon materials into final products. This makes it easy to obtain pure silicon that is highly capable of delivering the best performance when used in electronics.

 Secondly, silicon has a rich history in the world of electronics. The very first transistor was made of silicon. Since then, most electronic components have been made of the same material. History is important as it is proof that the materials can be used effectively in electronics. On the other hand, other semiconductor materials are still in their infancy stage.  Some manufacturers are not completely sure about the performance of these materials.

Silicon is a thermally stable material. It is rarely affected by different temperature variations. This makes it an ideal material for electronic applications that will be used in different environmental conditions.

Conclusion

When it comes to semiconductor chips, you have the freedom to choose different materials. Each material is packed with a unique set of properties and features. It is up to you to compare them and choose one that you think will deliver the best results.

Silicon has been around for many years. It is always a go-to choice for semiconductor chips since it has been fully tested and proven. However, the advancement of technology has paved the way for other semiconductor materials, SiGe and GaAs are among them. They have been fully adopted in the industry and are considered to be equal competitors to silicon.

You should fully consider the differences between all the differences before making the final choice. While at it, ensure that you choose a reliable IC supplier who will help you make the right choice. They should help you differentiate all three materials and then guide you on how to choose the right one for your application.

At Rantle East Electronic, we are a reputable IC chip distributor that is committed to serving all customers around the world. Using our experience and expertise, we will help you identify the types of materials that have been used on semiconductor chips.