What is Semiconductor Material?
Resistivity between metallic conductors ( 10 -5 ~ 10 –
6 [Omega] cm & lt ·) and the insulator ( 10 10 ~ 10 15 material between · cm)
Material properties can be controlled by methods such as purification, doping, and deep-level defect switching
The semiconductor material is usually a monocrystalline material
Progress has also been made in the research and application of polycrystalline and amorphous semiconductor materials, as well as recrystallized materials formed by laser annealing.
Characteristic parameters of semiconductor materials include: bandgap, electron and hole mobility, effective mass, diffusion coefficient, carrier lifetime, dielectric constant, lattice constant, and thermal conductivity
For the production of semiconductor devices, the selection of materials is mainly based on the characteristics of the semiconductor materials; the maturity of the material preparation process and the quality and price of the materials are also factors to consider
Semiconductor materials can be divided into semiconductor elements (such as silicon and germanium semiconductors), compound semiconductors (groups III-V, II-VI, IV-VI in the periodic table), amorphous and liquid semiconductors, and magnetic semiconductors according to their composition, structure and properties and semiconductor materials of organic metals, etc.
Semiconductor materials can be divided into bulk materials and epitaxial materials according to the growth process
Crystal growth methods of bulk materials are divided into Czochralski, liquid-sealed Czochralski, floating zone casting, and horizontal growth.
Methods for producing epitaxial materials include vapor phase epitaxy, organometallic compound epitaxy, liquid phase epitaxy, and molecular beam epitaxy.
Molecular beam epitaxy or other epitaxy methods can also be used to fabricate superlattice semiconductor materials.
Semiconductor materials have become the basis of the modern electronics industry
As early as the 1920s, selenium and cuprous oxide have been used as materials for rectifiers and photovoltaic cells.
During World War II, due to the need for radio guidance, research began on germanium and silicon as materials for the manufacture of crystal detectors and amplifiers.
In 1948, germanium transistors appeared; in 1950, silicon transistors were successfully developed
Since then, these two-element semiconductor materials (especially silicon) have developed rapidly.
In 1952 I began to study III-V compound semiconductor materials (indium antimonide, gallium arsenide, etc.
) The lattice structure of this compound is the same as that of silicon and germanium, and both belong to the lattice structure of diamond
In addition, extensive research has been conducted on other binary, ternary, and multicomponent compound semiconductor materials.
Among the various semiconductor materials, silicon has the most abundant resources, and the preparation and purification problems have also been solved.
Compared with other semiconductor materials, silicon also has the advantages of higher bandgap, higher intrinsic resistivity, longer carrier life, and easy surface passivation.
Therefore, silicon occupies a prominent place in semiconductor materials. Germanium has the characteristics of high purity and carrier mobility, and still has a certain application prospect in some devices (such as low-noise devices and detectors)
Among compound semiconductors, group III-V compounds are the most highly valued, and gallium arsenide is particularly prominent.
Due to the application of microwaves and optoelectronics, gallium arsenide has become the most promising semiconductor material after silicon.
Materials developed after gallium arsenide include indium phosphide, indium gallium arsenide, and phosphorous indium gallium arsenide.
In terms of materials used as infrared detectors, indium antimonide semiconductors, lead sulfide, lead tin tellurium, especially mercury, cadmium and tellurium compounds have been rapidly developed
The development of VLSI and solar cells has prompted people to conduct in-depth research on semiconductor materials.
The former has proposed higher requirements for microdefects, dislocations, stacking faults (see crystal defects) in silicon, and the thermal stability and uniformity of the semi-insulating gallium arsenide; pay more attention
Silicon, cadmium sulfide-copper sulfide, and gallium arsenide are all materials currently being studied.
Amorphous silicon has received more attention in recent years due to its small body size, better energy conversion efficiency, and suitability for mass production.
In this regard, people are exploring many new semiconductor materials.