最新訊息:Semiconductor material development and marketing

作者:tom 於 2017-12-06
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When talking about semiconductor materials, many people are concerned about its production process, but I pay more attention to the development prospects of semiconductor materials and its market competitiveness.

We know that the semiconductor material is the conductivity of 10 ~ 10 ohms/cm material. In general, semiconductor conductivity increases with increasing temperature, just the opposite of a metal conductor. Any of the above two characteristics of the material can be classified as semiconductor materials. The semiconductor material is one of the most important and most influential functional materials. It has an exclusive status in the field of microelectronics and is also the main material in the field of optoelectronics.

It is no exaggeration to say that semiconductor materials support the development of electronic information industry such as communications, computers, information appliances, and network technology. Semiconductor materials and their applications have become an important indicator of a country's economic development, technological progress, and national defense strength.

Semiconductor materials from discovery to development, from use to innovation, have a long history of this period. At the beginning of the twentieth century, point contact ore detectors appeared. In 1930, the success of the manufacture of cuprous oxide rectifier and has been widely used is the semiconductor material began to receive attention. 1947 made of germanium contact transistor, a breakthrough in the semiconductor research results. The late 50's, the development of thin film growth hormone and the invention of integrated circuits, microelectronics technology is further developed. In the 1960s, the gallium arsenide materials were used to make semiconductor lasers, the emergence of solid solution semiconductors, the research and development of Alio in infrared and the expansion of the application of semiconductor materials. The proposed concept of the superlattice in 1969 and the successful development of superlattice quantum well are the development of designing and manufacturing of semiconductor devices from impurity engineering to energy banding engineering and pushing the research and application of semiconductor materials to a new field. Since the 1990s, with the rapid development of mobile communication technology, semiconductor materials such as gallium arsenide and phosphating smoke have become the focus for making high-speed and high-frequency high-power exciting optoelectronic devices. In recent years, breakthroughs have been made in the research of new type semiconductor materials, Advanced gallium nitride represented by the beginning of advanced semiconductor materials to show superiority, known as the new engine of the IT industry.

Below, I through the information, briefly talk about the preparation of semiconductor materials.

Different semiconductor devices have different morphological requirements for semiconductor materials, including single crystal slicing, grinding, polishing, filming and the like. Different forms of semiconductor materials require different processing techniques. Commonly used semiconductor material preparation techniques are the purification, single crystal preparation, and film epitaxial growth.

All semiconductor materials require the raw material to be purified to a purity of 6 "9" or more and up to 11 "9" or more. Purification method is divided into two categories, one is without changing the chemical composition of the material to be purified, known as physical purification; the other is the first element into a compound to be purified, and then the purified compound is reduced to an element, known as Chemical purification. Physical purification methods are vacuum evaporation, refining the region, crystal pulling purification, the most used is the area of ​​refining. The main methods of chemical purification electrolysis, complexation, extraction, distillation, the most used are distillation. Due to the limitations of each method, several purification methods are often used to obtain qualified materials.

The vast majority of semiconductor devices are fabricated on single-wafer or wafer-on-wafer epitaxial wafers. Bulk semiconductor single crystals are made by melt growth. Czochralski method is the most widely used, 80% of the silicon single crystal, most of the germanium single crystal and indium antimonide single crystal is produced by this method, in which the maximum diameter of silicon single crystal has reached 300 mm. In the melt through the magnetic field of Czochralski called the magnetron crystal pulling method, this method has been produced with high uniformity of silicon single crystal. In the crucible melt surface by adding liquid coating agent called the liquid seal Carat method, using this method of a gallium arsenide, gallium phosphide, indium phosphide and other decomposition pressure larger single crystal. Floating zone melt does not contact with the container, using this method of growing high purity silicon single crystal. The horizontal zone melting method used to produce germanium single crystal. The horizontal directional crystallization method is mainly used for preparing gallium arsenide single crystal, while the vertical directional crystallization method is used for preparing cadmium telluride and gallium arsenide. The bulk single crystals produced by various methods are subjected to all or part of the steps of crystal orientation, barrel polishing, the reference surface, slicing, grinding, chamfering, polishing, etching, cleaning, testing and packaging to provide corresponding wafers.

The growth of single crystal thin films on single crystal substrates is called epitaxy. The methods of epitaxy include gas phase, liquid phase, solid phase and molecular beam epitaxy. Industrial production is mainly used for chemical vapor phase epitaxy, followed by liquid phase epitaxy. Metal-organic compounds vapor phase epitaxy and molecular beam epitaxy is used to prepare quantum wells and superlattice and other microstructures. Amorphous, microcrystalline, polycrystalline films and more in the glass, ceramics, metals and other substrates with different types of chemical vapor deposition, magnetron sputtering, and other methods.

Since we must pay attention to the development prospects of semiconductor materials and market potential, we must start from the current common trend of semiconductor materials research.

First, let's take a look at the most common and most widely used silicon materials to date. In order to improve the yield of silicon integrated circuits and reduce the cost, increasing the diameter of CZ-Si single crystal and reducing the density of micro-defects are still the general trend of CZ-Si development in the future.

From the perspective of further improving the speed and integration of silicon, the development of large-diameter silicon epitaxial wafers suitable for deep-submicron and even nanometer silicon processes will become the mainstream of silicon material development. In addition, SOI materials, including smart cut and SIMOX materials, have also developed rapidly.

Theoretical analysis indicates that the 30nm will be silicon MOS integrated circuit linewidth "limit" size. This not only refers to the physical limitations imposed by the effect of the quantum size effect on the existing device characteristics and the limitation of the lithography technique but more importantly, it is limited by the nature of the silicon itself. Although people are actively looking for high-K dielectric insulating materials (such as Si3N4 instead of SiO2, etc.), low-K dielectric interconnects, using Cu instead of Al wires and the use of system integration chip technology to improve ULSI's integration, computing speed And function, but silicon will eventually meet the human constant demand for greater information volume. To this end, in addition to seeking new principles based on quantum computing and biological calculation of DNA, etc., but also to GaAs, InP-based compound semiconductor materials, especially two-dimensional superlattice, quantum wells, one-dimensional quantum Line and zero-dimensional quantum dot material and silicon-planar process compatible GeSi alloy materials, which is currently the focus of semiconductor materials research and development.

Take a look at GaAs and InP single crystal materials. GaAs and InP are different from silicon in that they are all direct bandgap materials with high electron saturation drift speed, high-temperature resistance, and anti-radiation characteristics. In ultrahigh speed, ultrahigh frequency, low power consumption, low noise devices and circuits, especially Occupies a unique advantage in optoelectronic devices and optoelectronic integration.

The development trend of GaAs and InP single crystal is: Increase the crystal diameter; Improve the electrical and optical micro-area uniformity of the material;

Decreasing single crystal defect density, especially dislocation; GaAs and InP single crystal VGF growth technology is developing rapidly, is likely to become the mainstream technology.

Talk about semiconductor superlattice, quantum well material.

Thin-layer semiconductor ultra-thin layer of microstructure material is based on advanced growth technology (MBE, MOCVD) a new generation of artificial construction materials. It changes the design concept of optoelectronics and microelectronic devices with a brand new concept. A new category featuring "scalability of electrical and optical properties" is emerging. It is the foundation material for a new generation of solid-state quantum devices.

High-quality quantum well materials used for manufacturing quasi-continuous megawatt-class high-power laser arrays are attracting attention. Recently, researchers in our country proposed and carried out the study of vertical active-area vertical-cavity surface-emitting lasers in multi-active areas. This is a new laser with high gain, very low threshold, high power and high beam quality. In the future Optical communication, optical interconnection and optical information processing have a good application prospects. At present, Ⅲ-V superlattice and quantum well materials are the main directions for the development of ultrathin layer microstructured materials. In addition, silicon-based strained heterostructured materials have also become a major research direction.

Speaking of wide bandgap semiconductor materials, we mainly refer to diamond, group III nitride, silicon carbide, cubic boron nitride and oxides (such as ZnO) and solid solution, due to its high thermal conductivity, high electron saturation drift speed and large Critical breakdown voltage and other characteristics, as the development of high-frequency high-power, high temperature, anti-radiation semiconductor microelectronic devices and circuits ideal material; in communications, automotive, aviation, aerospace, oil exploration and defense has a wide range of applications . In addition, III-nitride is also a good optoelectronic material, has a wide range of applications. In recent years, the development of narrow bandgap InAsN, InGaAsN, GaNP and GaNAsP materials with anomalous bandgaps has also been emphasized. The company is located in:

Band gap semiconductor heterostructured materials are often also typical large mismatched heterostructure materials. The so-called large mismatched heterostructural materials refer to material systems that have large differences in physical parameters such as lattice constant, thermal expansion coefficient or crystal symmetry. Large lattice mismatch causes a large number of dislocations and defects at the interface, greatly affecting the optoelectronic properties of the microstructured materials and their device applications. How to avoid and eliminate this negative influence is an urgent scientific problem in material preparation. Solution to this problem, will greatly expand the material alternative, open up new areas of application.

In addition to the above four categories, there is a common semiconductor material - low-dimensional semiconductor materials.

In fact, the low-dimensional semiconductor materials mentioned here are nanomaterials. Essentially, one of the important purposes of developing nanoscience and technology is that people can control and manufacture powerful and superior performance on the scale of atomic, molecular or nano-scale Nano-electronics, optoelectronic devices and circuits, nano-biosensors and other devices for the benefit of mankind. It can be predicted that the development and application of nano-science and technology will not only completely change people's production and lifestyle but also change the pattern of social politics and the confrontation of war. This is why people attach great importance to the development of nanometer semiconductor technology.