From "simple" household appliances and computers to solar cells, field transistors, and unmanned vehicle chains, all technology requires the operation of semiconductors, and the modern world literally owes it its existence.
The obvious leader of the industry is now silicon, but it is not suitable for all instruments, and the physical properties of the semiconductor limit the ability to further miniaturize and increase the capacity of chips and create flexible devices. Fortunately, there are other alternative materials.
We're talking about semiconductors and what promising alternatives to silicon are for microelectronics, and more about the market as a whole can be read in the July issue of the robotics "Microelectronics: the less, the better" produced by the University of Innopolis.
What a Semiconductor Is
A semiconductor is a material that, by its specific conductivity, takes an intermediate place between conductors and dielectrics. It is typically a crystallic solid. Under certain conditions, it conducts electricity, which makes it ideal to control the current flow.
The conductors, in normal condition, conduct a small amount of current, or do not block it at all. But with a rise in temperature or light, they are better able to release electrical charges. Also, the conductivity of the conductors changes when the contamination is introduced; this process is called legation.
An important difference between the conductor and the conductor is that the current is transferred not only by electrons, but also by holes left by them. Holes left in the valent area can be occupied by electrons from lower energy states and thus contribute to current flow.
One of the key characteristics of a semiconductor is the mobility of chargers. This is a factor that shows the relationship between the average particle speed and the applied external electrical field. The movement of electrons and holes can be different, for example, in silicon at room temperature, the negative charged particles move almost three times faster than the positive ones.
In addition, semiconductors differ in the width of the prohibited area; this is the minimum energy required to transfer the electron from the valent area to the conductivity area; in metals and other semiconductors, it is 0; and when the level of 4 eV is reached, the material becomes dielectric.
Another important characteristic of semiconductors is thermal conductivity, which shows how quickly and simply it will be possible to divert the heat from the components to protect the device from overheating.
Silicon is the second most common chemical element on Earth after carbon. Its main advantage is that it is easy to extract, with silicon crystals relatively easy to operate, and it provides good common electrical and mechanical properties. Even though it is relatively low mobility of electrons and holes as long as it remains the optimal material for microelectronic production.
Another advantage is that when used in integrated circuits, it produces high-quality silicon oxide, which acts as insulation layers between different active elements.
The elements of monocrystal and polycrystal silicon are combined to increase the density of the elements and the speed of integrated circuits, and it is legalized to increase the conductivity of polycrystal silicon.
Silicon semiconductors are widely used to create integrated chips, bipolar and field transistors, charging devices, high-speed photodiodes and many other devices, and silicon-based products such as MOSFET- or IGBT-transistors with super-transistors can be used in a wide range of stresses and in different power classes.
We live in the "cream" era, and it may seem that the microelectronics started with this material, but the first one was Germany, and it was used in many early devices, from diodes to radar detection to first transistors, and it was until the late 1960s that it was the main conductor used in electronic devices, and it was only in the early 1970s that it was replaced by silicon.
The new "champion" is much more common, its production is cheaper, and it has a wider prohibited area and better thermal conductivity, but its advantage is that the chargers in this material are much more mobile.
For example, at a temperature of 300 K, electrons in the "first" semiconductor move almost three times faster than silicon and holes almost four times faster.
Although Germany is not suitable for modern microelectronics, it is still used in some radio frequency devices, such as microwave equipment, audio equipment and low-power and precision equipment.
The Gallium Arsenide is the second most common semiconductor used today. Unlike silicon and hermania, the Gallium Arsenide is a compound, not an element, and is produced by connecting a trivalent gallium to a arsenic with five valent electrons.
The large width of the prohibited area and the high mobility of electrons force the gallium arsenide-based devices to react quickly to electrical signals, making the compound suitable for increasing high frequency signals, and the material has shown its effectiveness at high temperatures and good resistance to radiation radiation.
Arsenid Gallium has long been used in microelectronics, so the production of devices is well-functioning. Due to its special properties, the material is used mainly to create ultra-high frequency microelectronics: digital and analog integrated circuits, discrete field transistors and Gunn diodes, which operate without p-n-diodes from their own material, and gallium arsenide chips are used in the manufacture of mobile phones, microwave devices, satellite communications devices and some radar systems.
However, it is a fragile material with smaller mobility holes than silicon, making it impossible to create devices such as, for example, CMS transistors, fast-activating and energy-efficient electronic circuits. It is also relatively difficult to manufacture, which increases the cost of gallium arsenide devices, and it has sufficiently low thermal conductivity to increase the risk of overheating devices.
Materials for the future
The width of the prohibited area of the diamond exceeds 3 eV, so by definition it's a dialect, but when the contamination is added, the precious stone becomes a semiconductor.
Theoretically, diamond semiconductors have excellent physical properties, including high thermal conductivity, field tension and vehicle mobility, which will significantly reduce losses, quickly diffuse heat and increase the lifetime of devices, and can also operate with an output capacity and energy efficiency of 50,000 times higher than for silicon devices and 1,200 times higher frequencies.
However, high-quality large-scale diamond plates are needed for industrial applications in electronic semiconductors, although efforts to create diamond instruments have been made for many years, and problems with the legation and processing of materials have not yet been resolved.
Graphene is a two-dimensional allotropic carbon modification. McKinsey predicts that the graphin has the potential to exceed silicon as a universal semiconductor material, but it can take up to 25 years to commercialize widely.
The key feature of this material is flexibility, so it can produce various sophisticated instruments; it is considered promising in terms of its continued use, and there are entire institutions around the world involved in research and development in the field of graphene.
It can be used in a wide range of industries, ranging from modern energy networks and alternative energy to biomedical, and in microelectronics, graphs can be used in ultra-sensitive microprocessors, quantum computer components and extreme sensors.
- Arsenid Bora.
Most recently, in July 2022, MIT researchers stated that they had found the best known semiconductors and found a cube arsenide of boron. This material is a compound of arsenic and boron.
Its thermal conductivity is 10 times greater than that of silicon, and unlike the last one and the arsenide of the gallia, the boron-based semiconductor shows high mobility not only for electrons but also for holes.
Although scientists say that this material is potentially a substitute for silicon, as is the case with graphene, it is still very far away from this; for example, it is necessary first to develop cheap ways to produce this material in quality.
Despite the high popularity and efficiency of Silicon Silicon Semiconductors, there are two factors that drive producers to do so: first, the technology has almost reached the limit beyond which it will not be possible to create ever more miniaturous and powerful devices; and second, the ever-increasing demand for Silicon has led to its cost.
The crisis of production during the coronavirus pandemic has shown how dangerous it is to rely on a single source, so companies and scientists around the world are working to create an alternative; however, it can be assumed that, thanks to the cheapness, accessibility and smoothness of the production of silicon instruments, this material will remain at the forefront of the microelectronics for some time to come.