“transistor”的概念、定义、翻译、参考文献-科学参考

transistor

Physics

A semiconductor device capable of amplification in addition to rectification. It is the basic unit in radio, television, and computer circuits, having almost completely replaced the thermionic valve. The point-contact transistor, which is now obsolete, was invented in 1948. It consists of a small germanium crystal with two rectifying point contacts attached to it; a third contact, called the base, makes a low-resistance nonrectifying (ohmic) connection with the crystal. Current flowing through the device between the point contacts is modulated by the signal fed to the base. This type of transistor was replaced by the junction transistor, which was developed in 1949–50. The field-effect transistor (FET) was a later invention. Bipolar transistors, such as the junction transistor, depend on the flow of both majority and minority carriers, whereas in unipolar transistors, such as the FET, the current is carried by majority carriers only.

In the bipolar junction transistor, two p-type semiconductor regions are separated by a thin n-type region, making a p−n−p structure. Alternatively, an n−p−n structure can also be used. In both cases the thin central region is called the base and one outer region of the sandwich is called the emitter, the other the collector. The emitter–base junction is forward-biased and the collector–base junction is reverse-biased. In the p−n−p transistor, the forward bias causes holes in the emitter region to flow across the junction into the base; as the base is thin, the majority of holes are swept right across it (helped by the reverse bias), into the collector. The minority of holes that do not flow from the base to the collector combine with electrons in the n-type base. This recombination is balanced by a small electron flow in the base circuit. The diagram illustrates the (conventional) current flow using the common-base type of connection. If the emitter, base, and collector currents are I_e, I_b, and I_c, respectively, then I_e=I_b+I_c and the current gain is I_c/I_b.

Transistors.

Field-effect transistors are of two kinds, the junction FET (JFET or JUGFET) and the insulated-gate FET (IGFET; also known as a MOSFET, i.e. metal-oxide-semiconductor FET). Both are unipolar devices and in both the current flows through a narrow channel between two electrodes (the gate) from one region, called the source, to another, called the drain. The modulating signal is applied to the gate. In the JFET, the channel consists of a semiconductor material of relatively low conductivity sandwiched between two regions of high conductivity of the opposite polarity. When the junctions between these regions are reverse-biased, depletion layers form, which narrow the channel. At high bias the depletion layers meet and pinch-off the channel completely. Thus the voltage applied to the two gates controls the thickness of the channel and thus its conductivity. JFETs are made with both n-type and p-type channels.

In the IGFET, a wafer of semiconductor material has two highly doped regions of opposite polarity diffused into it, to form the source and drain regions. An insulating layer of silicon dioxide is formed on the surface between these regions and a metal conductor is evaporated on to the top of this layer to form the gate. When a positive voltage is applied to the gate, electrons move along the surface of the p-type substrate below the gate, producing a thin surface of n-type material, which forms the channel between the source and drain. This surface layer is called an inversion layer, as it has opposite conductivity to that of the substrate. The number of induced electrons is directly proportional to the gate voltage, thus the conductivity of the channel increases with gate voltage. IGFETs are also made with both p-type and n-type channels. Because MOS devices cannot be formed on gallium arsenide (there are no stable native oxides of GaAs), metal semiconductor FETs (MESFET) devices are used. This makes use of Schottky barrier (see Schottky effect) as the gate electrode rather than a semiconductor junction.

Computer

A semiconductor device having, in general, three terminals that are attached to electrode regions within the device. Current flowing between two of these electrodes is made to vary in response to voltage or current variations imposed on the third electrode. The device is capable of current or voltage amplification depending on the particular circuit implementation employed. It can also be used as a switch by driving it between its maximum and minimum of current flow.
The transistor was invented in 1948 by Shockley, Brattain, and Bardeen at Bell Telephone Labs. As performance and manufacturing techniques improved, the transistor enabled a huge growth in computer technology.
See also bipolar transistor, field-effect transistor, MOSFET.

Electronics and Electrical Engineering

A multielectrode semiconductor device in which the current flowing between two specified electrodes is controlled or modulated by the voltage applied at the third (control) electrode. The term transistor was originally derived from the phrase transfer resistor, as the resistance of the output electrodes was controlled by the input circuit (transferred). Transistors fall into two major classes: the bipolar junction transistor (BJT) and the field-effect transistor (FET).
The bipolar junction transistor was derived from the point-contact transistor, which was invented at Bell Telephone Laboratories in 1947 by Bardeen, Brattain, and Shockley. The BJT comprises two p-n junctions placed back-to-back in close proximity, creating three regions in the device – emitter, base, and collector. It utilizes the flow of both electrons and holes across the junctions for its electrical behaviour. The current flow through the emitter and collector electrodes is controlled by the voltage across the base–emitter p-n junction.
In the case of the field-effect transistor, the current flow inside the transistor between source and drain electrodes is controlled by the internal electric field, which is a function of the voltage applied at the third terminal, the gate. The junction field effect transistor (JFET) was invented at Bell Laboratories by Shockley in 1952. In this device the current flow is in the bulk of the semiconductor, along a channel whose cross-sectional area is controlled by the width of the depletion region associated with a reverse-biased p-n junction formed by the gate and channel semiconductors. The current flow is thus in the region of the channel that is free of the gate field.
In a surface field-effect transistor, the current flow is along a surface of the semiconductor that is separated from the gate electrode by an insulating region. Such a device is known as an insulated-gate field-effect transistor, exemplified by the MOSFET. The surface field-effect transistor was first proposed in the 1930s. It was only realized practically in 1960, when device technology had improved sufficiently to reduce the density of surface defects to a low enough level to enable control of the surface potential by an applied voltage.
http://www.pbs.org/transistor/index.htmlA A short history of transistors, on the PBS website

单词	transistor
释义	transistor Physics A semiconductor device capable of amplification in addition to rectification. It is the basic unit in radio, television, and computer circuits, having almost completely replaced the thermionic valve. The point-contact transistor, which is now obsolete, was invented in 1948. It consists of a small germanium crystal with two rectifying point contacts attached to it; a third contact, called the base, makes a low-resistance nonrectifying (ohmic) connection with the crystal. Current flowing through the device between the point contacts is modulated by the signal fed to the base. This type of transistor was replaced by the junction transistor, which was developed in 1949–50. The field-effect transistor (FET) was a later invention. Bipolar transistors, such as the junction transistor, depend on the flow of both majority and minority carriers, whereas in unipolar transistors, such as the FET, the current is carried by majority carriers only. In the bipolar junction transistor, two p-type semiconductor regions are separated by a thin n-type region, making a p−n−p structure. Alternatively, an n−p−n structure can also be used. In both cases the thin central region is called the base and one outer region of the sandwich is called the emitter, the other the collector. The emitter–base junction is forward-biased and the collector–base junction is reverse-biased. In the p−n−p transistor, the forward bias causes holes in the emitter region to flow across the junction into the base; as the base is thin, the majority of holes are swept right across it (helped by the reverse bias), into the collector. The minority of holes that do not flow from the base to the collector combine with electrons in the n-type base. This recombination is balanced by a small electron flow in the base circuit. The diagram illustrates the (conventional) current flow using the common-base type of connection. If the emitter, base, and collector currents are I_e, I_b, and I_c, respectively, then I_e=I_b+I_c and the current gain is I_c/I_b. Transistors. Field-effect transistors are of two kinds, the junction FET (JFET or JUGFET) and the insulated-gate FET (IGFET; also known as a MOSFET, i.e. metal-oxide-semiconductor FET). Both are unipolar devices and in both the current flows through a narrow channel between two electrodes (the gate) from one region, called the source, to another, called the drain. The modulating signal is applied to the gate. In the JFET, the channel consists of a semiconductor material of relatively low conductivity sandwiched between two regions of high conductivity of the opposite polarity. When the junctions between these regions are reverse-biased, depletion layers form, which narrow the channel. At high bias the depletion layers meet and pinch-off the channel completely. Thus the voltage applied to the two gates controls the thickness of the channel and thus its conductivity. JFETs are made with both n-type and p-type channels. In the IGFET, a wafer of semiconductor material has two highly doped regions of opposite polarity diffused into it, to form the source and drain regions. An insulating layer of silicon dioxide is formed on the surface between these regions and a metal conductor is evaporated on to the top of this layer to form the gate. When a positive voltage is applied to the gate, electrons move along the surface of the p-type substrate below the gate, producing a thin surface of n-type material, which forms the channel between the source and drain. This surface layer is called an inversion layer, as it has opposite conductivity to that of the substrate. The number of induced electrons is directly proportional to the gate voltage, thus the conductivity of the channel increases with gate voltage. IGFETs are also made with both p-type and n-type channels. Because MOS devices cannot be formed on gallium arsenide (there are no stable native oxides of GaAs), metal semiconductor FETs (MESFET) devices are used. This makes use of Schottky barrier (see Schottky effect) as the gate electrode rather than a semiconductor junction. Computer A semiconductor device having, in general, three terminals that are attached to electrode regions within the device. Current flowing between two of these electrodes is made to vary in response to voltage or current variations imposed on the third electrode. The device is capable of current or voltage amplification depending on the particular circuit implementation employed. It can also be used as a switch by driving it between its maximum and minimum of current flow. The transistor was invented in 1948 by Shockley, Brattain, and Bardeen at Bell Telephone Labs. As performance and manufacturing techniques improved, the transistor enabled a huge growth in computer technology. See also bipolar transistor, field-effect transistor, MOSFET. Electronics and Electrical Engineering A multielectrode semiconductor device in which the current flowing between two specified electrodes is controlled or modulated by the voltage applied at the third (control) electrode. The term transistor was originally derived from the phrase transfer resistor, as the resistance of the output electrodes was controlled by the input circuit (transferred). Transistors fall into two major classes: the bipolar junction transistor (BJT) and the field-effect transistor (FET). The bipolar junction transistor was derived from the point-contact transistor, which was invented at Bell Telephone Laboratories in 1947 by Bardeen, Brattain, and Shockley. The BJT comprises two p-n junctions placed back-to-back in close proximity, creating three regions in the device – emitter, base, and collector. It utilizes the flow of both electrons and holes across the junctions for its electrical behaviour. The current flow through the emitter and collector electrodes is controlled by the voltage across the base–emitter p-n junction. In the case of the field-effect transistor, the current flow inside the transistor between source and drain electrodes is controlled by the internal electric field, which is a function of the voltage applied at the third terminal, the gate. The junction field effect transistor (JFET) was invented at Bell Laboratories by Shockley in 1952. In this device the current flow is in the bulk of the semiconductor, along a channel whose cross-sectional area is controlled by the width of the depletion region associated with a reverse-biased p-n junction formed by the gate and channel semiconductors. The current flow is thus in the region of the channel that is free of the gate field. In a surface field-effect transistor, the current flow is along a surface of the semiconductor that is separated from the gate electrode by an insulating region. Such a device is known as an insulated-gate field-effect transistor, exemplified by the MOSFET. The surface field-effect transistor was first proposed in the 1930s. It was only realized practically in 1960, when device technology had improved sufficiently to reduce the density of surface defects to a low enough level to enable control of the surface potential by an applied voltage. http://www.pbs.org/transistor/index.htmlA A short history of transistors, on the PBS website
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