Commonly used semiconductor materials include silicon (Si), germanium (Ge), gallium arsenide (GaAs) and cadmium sulfide (CdS). These materials are widely used in electronic industry, such as integrated circuits, sensors, solar cells and so on.
To select suitable semiconductor materials, we must first clarify the application requirements. For example, silicon is the preferred material for most integrated circuits because of its excellent cost performance and stability. In the field of optoelectronics, gallium arsenide is often used in high-efficiency light-emitting diodes and lasers because of its direct band gap characteristics.
In addition to performance, the cost and availability of materials should also be considered. Silicon is a rich element in the earth's crust, so it is relatively cheap and easy to collect. However, some special semiconductor materials, despite their excellent performance, may not be suitable for some commercial applications because they are difficult to produce on a large scale or expensive.
Environmental factors are also an important consideration. Choosing materials whose production process has less impact on the environment can help enterprises reduce their carbon footprint and realize green and sustainable production.
Choosing suitable semiconductor materials requires comprehensive consideration of its performance, cost, accessibility and environmental impact to ensure that it can meet the needs of specific applications.
Figure1: the development process of semiconductor through the edges
Common semiconductor material brief introduction
Silicon (Si)
Silicon is the most widely used semiconductor material at present, and almost all integrated circuits use silicon as the substrate. Silicon has a high melting point, can withstand high temperature treatment in the manufacturing process, and has good electrical properties and cost-effectiveness. Its richness is also one of the main reasons why silicon has become the preferred semiconductor material.
Germanium (Ge)
Germanium is an early semiconductor material, which has better carrier mobility than silicon. However, due to its high cost and low melting point, its application in integrated circuits has been reduced. However, in recent years, due to its application in infrared detectors and high-speed devices, germanium has attracted attention again.
Group 35 semiconductors: such as gallium arsenide (GaAs)
Gallium arsenide is the representative of Group 35 semiconductors, which has higher electron mobility than silicon and germanium, so it is often used in high frequency and highly speed applications. At the same time, because of its direct band gap characteristics, it is also widely used in light-emitting diodes and solar cells.
Group 26 semiconductors: such as cadmium sulfide (CdS)
Cadmium sulfide is one of the most widely used semiconductor materials in the field of optoelectronics. Because of its excellent optical properties, cadmium sulfide is often used in photodetectors, solar cells and thin film transistors.
Basic physical properties of semiconductor materials
Band gap
Band gap describes the energy difference between the highest energy level of valence band and the lowest energy level of conduction band. This is the key factor to determine whether semiconductor materials can conduct electricity at a given energy. For example, silicon has a band gap of 1.1 electron volts, which makes it a good semiconductor at room temperature. The size of the band gap also affects the color of the material and whether it is sensitive to light of a specific wavelength.
Semiconductor technology
Electrical conductivity
Conductivity is a measure of the conductivity of materials, which is usually related to carrier concentration and mobility. Different semiconductor materials have different intrinsic conductivity, which also depends on their doping level. Conductivity directly affects the switching speed and power consumption of equipment.
Carrier mobility
Carrier mobility describes the speed at which carriers (electrons or holes) move under the action of an electric field. Generally speaking, high mobility means that carriers can move faster under the same electric field, thus making semiconductor devices work faster. For example, the carrier mobility of germanium is higher than that of silicon, which makes germanium advantageous in high-speed applications.
Selection of Semiconductor Materials in Specific Application Scenarios
Digital circuit
Digital circuit is the core of modern electronic equipment, which is responsible for processing and storing data. In this application, silicon is widely used because of its good cost performance, mature process technology and reliability. Silicon-based CMOS technology is the mainstream of current digital circuits, providing low-power, high-density and high-performance solutions. However, with the reduction of size, new semiconductor materials such as graphene and 2D materials have gradually attracted researchers' attention.
Optoelectronic element
In the field of optoelectronics, semiconductor materials are needed to respond to light, such as solar cells, light-emitting diodes, lasers and so on. Gallium arsenide is widely used in light emitting diodes and lasers because of its direct band gap characteristics. Cadmium sulfide or cadmium selenide are often used as the main materials of thin film solar cells, because they provide good light absorption characteristics.
Power semiconductor
Power semiconductors are used to handle large currents and high voltages. In these applications, materials with high breakdown voltage and low on-resistance are needed. Silicon carbide (SiC) and gallium nitride (GaN) stand out in such applications because of their high band gap and good thermal stability. They not only provide high efficiency and highly power density, but also have excellent performance in high temperature environment.
Semiconductor material
Consideration of environmental and cost factors
Material procurement and cost
When choosing semiconductor materials, its accessibility and cost are one of the main considerations. Silicon, for example, is an inexpensive and readily available choice because of its abundance in the Earth's crust. However, some new or special semiconductor materials, such as gallium nitride or some organic semiconductors, may be costly because their production or refining process is more complex and expensive. Therefore, the economy of materials should be fully considered when formulating production strategies.
Environmental impact of production process
With the enhancement of environmental protection awareness, semiconductor industry is paying more and more attention to the impact of its production process on the environment. For example, many semiconductor manufacturing processes require the use of hazardous chemicals, which may pose a threat to the environment and human health. Therefore, it is particularly important to choose materials and processes that are more environmentally friendly and can reduce the use of harmful substances. In addition, with the popularization of renewable energy, how to make semiconductor manufacturing greener and lower carbon has become a research hotspot.
Brand-new semiconductors material prospect
Two-dimensional materials: such as graphene
Graphene is a two-dimensional material composed of a single layer of carbon atoms, which has many unique properties, such as ultra-high electron mobility, strength and thermal conductivity. Because of its atomic thickness, graphene shows great potential in nanoscale semiconductor applications, such as manufacturing transparent conductive layers or high-speed electronic devices. However, its zero bands gap property brings challenges to practical application. Therefore, researchers are exploring other two-dimensional materials, such as transition metal chalcogenides, to achieve multiple functions.
Organic semiconductor materials
Organic semiconductor materials are mainly composed of carbon-based molecules or polymers, which is different from traditional inorganic semiconductors. These materials show great application potential in organic light emitting diodes (OLED) and organic solar cells. Because they can be processed by solution processing or printing technology, organic semiconductors are expected to realize low-cost and large-area electronic applications.
New high temperature superconductor
High temperature superconductor is a material that shows zero resistance at relatively high temperature. Although these materials are mainly used in magnets and energy storage, they also bring new research directions in the field of semiconductors. High temperature superconductors can realize superconductivity without cooling, which may provide new opportunities for ultra-high speed electronic devices and quantum computing in the future.
Semiconductor technology
Summary and Suggestions
Choose according to specific needs
The selection of semiconductor materials should be based on the requirements of specific applications. For example, high-speed electronic applications may give priority to materials with high carrier mobility, while photoelectric applications may give priority to materials with good response to specific wavelengths of light. In addition, from an economic and environmental point of view, it is also very important to choose materials that are easily available, inexpensive and environmentally friendly in the production process.
Future development trend and research direction
With the development of science and technology, new semiconductor materials and technologies are constantly emerging. New materials such as two-dimensional materials, organic semiconductors and high-temperature superconductors are all semiconductor field bring a new research direction. At the same time, in order to cope with the increasingly serious environmental problems, green and sustainable semiconductor manufacturing technology has also attracted more and more attention. For enterprises and research institutions, keeping up with technology trends and investing in future technologies and solutions are the key to long-term success.
Notes and common misunderstandings
When selecting semiconductor materials, we should not only consider their performance indexes, but also deeply understand the physical and chemical properties of materials and their performance in practical applications. In addition, different application scenarios and working conditions may have an impact on the performance of semiconductor materials, so the selection of materials should be comprehensively considered in combination with actual needs.
What are the commonly used semiconductor materials and how to choose the appropriate ones? -China.exportsemi.com
