What are the two types of impurity semiconductors?

Electronic semiconductorsand hole-type semiconductors. Electronic semiconductors use electrons as the majority carriers.

of the peninsula material, which is formed by the introduction of the main type of impurities. Hole-type semiconductors are semiconductors that are mainly positively charged with holes.

When trace impurities are incorporated into semiconductors, the periodic potential field near the impurity atoms is disturbed and an additional binding state is formed, resulting in an additional impurity energy level in the band gap.

N-type semiconductors, p-type semiconductors.

1. N-type semiconductors are doped with trace amounts of 5-valent elements, such as phosphorus, in intrinsic semiconductor silicon (or germanium), then phosphorus atoms replace a small number of silicon atoms in the silicon crystal and occupy some positions on the crystal lattice.

2. In intrinsic semiconductor silicon (or germanium), if a trace amount of 3-valent elements, such as boron, are added, then boron atoms replace a small number of silicon atoms in the crystal and occupy some positions on the crystal lattice.

Type semiconductors are incorporated with trace amounts of pentavalent elements (such as phosphorus) in intrinsic semiconductor silicon (or germanium) through a semiconductor process

If trace amounts of 5-valent impurity elements such as phosphorus, antimony, arsenic, etc., are doped into the intrinsic semiconductor silicon (or germanium), since the outermost shell of the impurity atom has 5 valence electrons, when 4 of them form a covalent bond with the silicon atom, there will be an extra 1 valence electron. This electron is only attracted by its own nucleus, not bound by covalent bonds, and can become a free electron at room temperature, as shown in Figure 22(a).

Phosphorus (or antimony, arsenic) atoms lose one electron and become immobile positive ions. The more impurity elements are incorporated, the higher the concentration of free electrons and the greater the number. And in this impurity semiconductor, the electron concentration is much greater than the hole concentration.

Therefore, electrons are called majority carriers (referred to as manytons) and holes are called minority carriers (few carriers for short). Under the action of an external electric field, the current of this impurity semiconductor is mainly an electronic current. Since electrons are negatively charged, this type of semiconductor, which conducts electrons dominantly, is called n-type semiconductor.

There are four categories: integrated circuits, discrete devices, sensors and optoelectronic devices.

According to the internationally accepted standard method of semiconductor production and combustion products, semiconductors can be divided into four categories: integrated circuits, discrete devices, sensors and optoelectronic devices, which can be collectively referred to as semiconductor components.

Semiconductor process:

Semiconductor process refers to a complete set of skin-return process system formed according to scientific theory and production practice research from raw materials to finished semiconductor devices.

The basic knowledge of semiconductor process mainly includes the knowledge of process flow, component preparation, packaging and testing.

The process includes on-chip process, component packaging, system packaging and testing, etc.

Component preparation includes integrated circuit packaging, perforation, surface treatment, etc. The packaging types cover plastic packaging, metal packaging, etc. The test types include closed-state performance test, hot pressing test, capacitance test, etc.

It includes knowledge of materials science, physics, chemistry, electronics, and microelectronic processes that enable the manufacture of high-performance semiconductor products. <>

1. N-type semiconductors.

N-type semiconductors are also known as electron-type semiconductors, i.e., impurity semiconductors with a concentration of free electrons much greater than the concentration of holes.

Principle of formation. Both doping and defects can lead to an increase in the concentration of electrons in the conduction band. For germanium and silicon semiconductor materials, doped with group elements, when the impurity atoms replace the germanium and silicon atoms in the crystal lattice by substitution, a superfluous electron can be supplied in addition to satisfying the covalent bond coordination, which forms an increase in the concentration of conduction band electrons in the semiconductor, and the impurity atoms are called donors.

The donors of group compound semiconductors tend to use OR group elements. Some oxide semiconductors, their chemical ratio often presents hypoxia, these oxygen vacancies can show the role of donor, so this type of oxide is usually electronically conductive, that is, n-type semiconductors, vacuum heating, can further enhance the degree of hypoxia.

2. P-type semiconductors.

P-type semiconductors generally refer to hole-type semiconductors, which are mainly positively charged hole-conductive semiconductors.

Formation. P-type semiconductors are formed by adding trivalent elements (such as boron) to pure silicon crystals to replace the position of silicon atoms in the crystal lattice. In p-type semiconductors, holes are many, and free electrons are few, and they mainly rely on holes to conduct electricity.

Since the amount of positive charge and the amount of negative charge in p-type semiconductors are equal, p-type semiconductors are electrically neutral. Holes are mainly provided by impurity atoms, and free electrons are formed by thermal excitation.

Features: 1) N-type semiconductor.

Since the amount of positive charge and the amount of negative charge in n-type semiconductors are equal, n-type semiconductors are electrically neutral. Free electrons are mainly provided by impurity atoms, and holes are formed by thermal excitation. The more incorporated impurities are disturbed and leaked, the higher the concentration of polysons (free electrons) and the stronger the conductivity.

2) P-type semi-slow carrying conductor.

The more impurities are incorporated, the higher the concentration of polysons (holes) and the stronger the conductivity.

Impurity semiconductors, as the name suggests, are semiconductors that contain impurities. Impurities in semiconductors are conductivity to electricity.

The influence is very large, and intrinsic semiconductors are doped to form impurity semiconductors. Impurity semiconductors can generally be classified into n-type semiconductors.

and p-type semiconductors. When a trace amount of impurities is doped in a semiconductor, the periodic potential field near the impurity atoms is disturbed and an additional binding state is formed, resulting in an additional impurity energy level in the band gap. Electron carriers can be supplied.

The impurities are called donor impurities, and the corresponding energy levels are called donor energy levels, which are located above the forbidden band near the bottom of the conduction band. For example, when the tetravalent element germanium or silicon crystal is doped with impurity atoms such as pentavalent elements phosphorus, arsenic, antimony, etc., the impurity atom is a member of the crystal lattice and its five valence electrons.

There are four of them that form covalent bonds with the surrounding germanium (or silicon) atoms.

The extra electron is bound to the impurity atom, creating a shallow hydrogen-like energy level – the donor level. The energy required for the electron transition to the conduction band on the donor energy level is much smaller than the energy required to excite the conduction band from the valence band to the conduction band, and it is easy to excite the conduction band to become an electron carrier, so for semiconductors doped with donor impurities, the conductive carriers are mainly the electrons excited into the conduction band, which belong to the electron conductive type. Semiconductors in which most of the carriers in the semiconductor are electrons are called n-type semiconductors.

Since there are always intrinsically excited electron-hole pairs in semiconductors, the electrons are the majority carriers and the holes are the few carriers in n-type semiconductors. The corresponding impurities that can provide hole carriers are called acceptor impurities, and the corresponding energy levels are called acceptor levels, which are located below the band gap near the top of the valence band. For example, when impurity atoms such as boron, aluminum, gallium and other trace trivalent elements are doped in germanium or silicon crystals, the impurity atoms lack an electron when they form a covalent bond with the surrounding four germanium (or silicon) atoms, so there is a vacancy, and the energy state corresponding to this vacancy is the acceptor energy level.

Since the acceptor energy level is close to the top of the valence band, the electrons in the valence band are easily excited to the acceptor energy level to fill this vacancy, making the acceptor impurity atom become the negative center. At the same time, a vacancy is left in the valence band due to the ionization of an electron, forming a free hole carrier, and the ionization energy required for this process is much smaller than that of the intrinsic semiconductor case. Therefore, the holes are the majority of carriers, and the impurity semiconductors mainly rely on holes to conduct electricity, that is, the hole conductive type.

Semiconductors with most carriers are holes are called p-type semiconductors. In p-type semiconductors, holes are the majority carriers and electrons are the minority carriers. A small number of carriers often play an important role in the various effects of semiconductor devices.

Depending on the type and amount of impurities incorporated, semiconductors can be classified into ()aBenchang repents of semiconductors.

type of semiconductors. type of semiconductors.

d.Highly compensated semiconductors.

Correct Answer: N-type semiconductors are quick to disrupt; p-type semiconductors; Highly compensated semiconductors.