Semiconductor Glossary, Developed Semi OneSource.
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With over 2000 terms defined and explained, Semiconductor Glossary is the most complete reference in the field of semiconductors on the market today.












Including some 500 new terms defined and remaining terms updated and modified, a 2nd edition book version of this glossary is now available.


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Term (Index) Definition
transistor  three-terminal semiconductor device in which input signal (voltage or current depending on the type of transistor) controls output current; the most important semiconductor device; performs switching and amplifying functions; early on replaced bulky and inefficient vacuum triode in electronic circuits; invention of transistor (Schockley, Brattain and Bardeen, 1947) triggered electronic revolution after the World Word II; can operate as a discrete device or a building cell of integrated circuits; numerous kinds of transistors can be distinguished based on their design and principles of operation; there are two types of transistors: unipolar (field-effect transistor, or FET) and bipolar.

Reference: See history of transistor
bipolar device  semiconductor device which operation is based on the use of both majority and minority charge carriers; all p-n junction based devices fall into this category; alternative to unipolar device.
unipolar device  semiconductor device which operation is based predominantly on the use of majority charge carriers e.g. all transistors based on the field effect fall into this category; alternative to bipolar device.
Term (Index) Definition
bipolar transistor, BJT  Bipolar Junction Transistor; a transistor consisting of three semiconductor regions (emitter, base, and collector) with alternating conductivity type (i.e. n-p-n or p-n-p); current flow comprises both majority and minority carriers (hence, "bipolar"), is controlled by vertical dimensions; current controlled device; key transistor structure in semiconductor electronics.
base  region in bipolar transistor sandwiched between emitter and collector; typically n-type so that highly mobile electrons act as minority carriers in the base; should be very thin to allow rapid transfer of minority carriers from emitter to collector; electric field is created in the base by nonuniform doping to accelerate minority carriers moving from emitter to collector.
collector  region in bipolar transistor collecting carriers from the base; should be lightly doped to assure proper transistor operation.
emitter  very high conductivity region in semiconductor devices acting as a source of free majority carriers typically injected into the adjacent region (for instance into base in the bipolar transistor)
HBT  Heterojunction Bipolar Transistor; very high-performance transistor structure; unlike conventional bipolar transistor built using more than one semiconductor material, hence "heterojunction"; takes advantage of different bandgap of semiconductors used to form emitter, base and collector; e.g. n-AlGaAs/p-GaAs/n-GaAs, or SiGe in combination with Si; formed using high precision epitaxy such as MBE or MOCVD.
Term (Index) Definition
Double-Gate Transistor  a new generation of MOSFETs shaped in such way that the MOS gate is formed on the two sides of an active Si region.
Term (Index) Definition
DST, Depleted Substrate Transistor  Depleted Substrate Transistor represents a new generation of MOSFETs built into the SOI substrate in such way that its active Si layer between source and drain is fully depleted creating high conductivity channel; elimination of junction capacitances results in the device featuring superior characteristics.
fully depleted SOI, FD SOI  possible in SOI substrates with ultra-thin active silicon layer; under typical gate voltage in CMOS depletion/inversion region in silicon under the gate expands all the way to the insulator. See www.semiconductornotes.com "SOI Wafers"
Term (Index) Definition
Field Effect Transistor, FET  transistor in which output current (source-drain current)is controlled by the voltage applied to the gate which can be either an MOS structure (MOSFET), a p-n junction (JFET), or metal-semiconductor contact (MESFET); FET is an unipolar transistor, i.e. current is controlled by majority carriers only.
drain  heavily doped region in semiconductor substrates located at the end of the channel in Field Effect Transistors; carriers are flowing out of the transistor through the drain.
gate  structure used to control output current (i.e. flow of carriers in the channel) in the field effect transistor (FET); in MOSFET gate is comprised of gate contact and thin oxide; in MESFET gate is a Schottky contact; in JFET: metal and p-n junction.
JFET  Junction Field Effect Transistor; field effect transistor in which channel and its conductivity is controlled by changing width of the space charge region associated with a p-n junction.
MESFET  Metal Semiconductor Field Effect Transistor; FET with metal-semiconductor contact (Schottky diode) as a gate; allows implementation of field effect transistor with semiconductors which do not have high quality native oxide (e.g. GaAs), and hence, are not compatible with MOS gate approach.
MOSFET  Metal-Oxide-Semiconductor Field Effect Transistor; FET with MOS structure as a gate; current flows in the channel between source and drain; channel is created by applying adequate potential to the gate contact and inverting semiconductor surface underneath the gate; MOSFET structure is implemented almost uniquely with Si and SiO2 gate oxide; efficient switching device which dominates logic and memory applications; PMOSFET (p-channel, n-type Si substrate) and NMOSFET (n-channel,p-type Si substrate) combined form basic CMOS cell.
source  one of three terminals in Field Effect Transistors; a heavily doped region from which majority carriers are flowing into the channel.
Term (Index) Definition
First 45 nm transistor  Intel's transistor which uses 45 nm technology and which employs high-k gate dielectric and metal gate contacts to push transistor performance to unprecedented levels (e.g. 20 % improvement in transistor switching speed as compared to 65 nm technology)

Reference: First 45 nm transistor
gate contact  conducting material (metal, poly Si, or silicide) in the gate structure.
gate dielectric  very thin layer of an insulator sandwiched between semiconductor and gate contact in MOS devices; in silicon technology it is typically a thermally grown SiO2, often nitrided; depending on application it can be as thin as 1.0-1.5 nm (advanced digital integrated circuits) and as thick as 50 nm (discrete power MOSFETs); in ultra-small geometry CMOS ICs SiO2 is replaced with insulators featuring higher than SiO2 dielectric constant; hafnium based dielectrics (oxide or silicate) are materials of choice in this case.
high-k dielectric  dielectric material featuring dielectric constant k higher than 3.9 which is k of SiO2; used as gate dielectric (amorphous) in MOS devices and in storage capacitors; high k increases capacitance, or keeps in unchanged at the reduced area of MOS gate and gate dielectric sufficiently thick to prevent excessive tunneling current.

Reference: See Semiconductor Notes for more information
metal MOS gate  for many years metals were not used as gate contact material in MOS/CMOS devices; instead, conducting poly-Si is used due to the work function matching work function of Si substrate (precondition for the low threshold voltage of an MOSFET); metal contacts are re-introduced to the mainstream CMOS technology at the time when high-k dielectrics are replacing SiO2 as a gate oxide in cutting edge CMOS technology(poly-Si forms an SiOx layer at the interface with gate dielectric; also Fermi level pinning may occur); different metals must be used as gate contacts in NMOS and PMOS part of the CMOS cell.
Term (Index) Definition
integrated bipolar transistor  to meet specific requirements of the layout of an integrated circuit collector contact in an integrated bipolar transistor is located on the top surface of the wafer along with emitter and base contacts; in the disctrete bipolar transistor collector contact is located on the back surface of the wafer; this change enforces changes in a configuration of the entire collector region of the bipolar transistor.
Term (Index) Definition
lateral transistor  bipolar transistor in which current flows across the base in the direction parallel to the wafer surface; in contrast to conventional vertical bipolar transistor in which current across the base flows in the direction normal to the surface; l.t. features inferior characteristics as compared to vertical transistor.
vertical transistor  bipolar transistor in which current across emitter-base and collector-base junctions flows in the direction normal to the wafer surface; conventional configuration as opposed to lateral transistor which features inferior characteristics.
Term (Index) Definition
planar transistor  transistor, or other semiconductor device, manufactured using planar process, i.e. processes in which geometry of doped regions is defined by the pattern created in the masking oxide.
Term (Index) Definition
Schottky clamped transistor  n-p-n transistor with Schottky diode connecting base and collector; the role of Schottky diode is to drive excess minority carriers from the transistor base during switching, and hence, to reduce storage time.
Schottky diode  semiconductor diode in which metal-semiconductor contact is used to form a potential barrier.
Term (Index) Definition
TeraHertz Transistor  transistor operating in the e12 Hz (1,000 GHz) frequency range; uses SOI substrate (DST), high-k gate dielectric and raised source and drain.
raised source-drain  feature of the advanced CMOS/MOSFET design; source and drain regions are raised (additional layer of Si is deposited epitaxially)with respect to the plane of the gate oxide-Si substrate interface to improve device performance.
DST, Depleted Substrate Transistor  Depleted Substrate Transistor represents a new generation of MOSFETs built into the SOI substrate in such way that its active Si layer between source and drain is fully depleted creating high conductivity channel; elimination of junction capacitances results in the device featuring superior characteristics.
Term (Index) Definition
TFT, Thin Film Transistor  Thin Film Transistor; a Metal-Oxide-Semiconductor Field Effect Transistor implemented using thin film technology; uses thin films of either polycrystalline or amorphous silicon (or other thin film semiconductors, e.g. organic) and a variety of insulating substrates; compatible with liquid crystal display (LCD) technology; used in active matrix LCDs.
transistor  three-terminal semiconductor device in which input signal (voltage or current depending on the type of transistor) controls output current; the most important semiconductor device; performs switching and amplifying functions; early on replaced bulky and inefficient vacuum triode in electronic circuits; invention of transistor (Schockley, Brattain and Bardeen, 1947) triggered electronic revolution after the World Word II; can operate as a discrete device or a building cell of integrated circuits; numerous kinds of transistors can be distinguished based on their design and principles of operation; there are two types of transistors: unipolar (field-effect transistor, or FET) and bipolar.

Reference: See history of transistor
Term (Index) Definition
transistor leakage  term refers to undesired current that flows when transistor is in the "off" state; in advanced MOS/CMOS devices using ultra-thin gate oxide leakage current is primarily a tunneling current across the gate oxide.
Term (Index) Definition
unipolar transistor  synonymous with Field Effect Transistor, FET, i.e. transistor which operation is controlled by majority carriers only.
bipolar transistor, BJT  Bipolar Junction Transistor; a transistor consisting of three semiconductor regions (emitter, base, and collector) with alternating conductivity type (i.e. n-p-n or p-n-p); current flow comprises both majority and minority carriers (hence, "bipolar"), is controlled by vertical dimensions; current controlled device; key transistor structure in semiconductor electronics.
Field Effect Transistor, FET  transistor in which output current (source-drain current)is controlled by the voltage applied to the gate which can be either an MOS structure (MOSFET), a p-n junction (JFET), or metal-semiconductor contact (MESFET); FET is an unipolar transistor, i.e. current is controlled by majority carriers only.
Term (Index) Definition
vertical transistor  bipolar transistor in which current across emitter-base and collector-base junctions flows in the direction normal to the wafer surface; conventional configuration as opposed to lateral transistor which features inferior characteristics.
lateral transistor  bipolar transistor in which current flows across the base in the direction parallel to the wafer surface; in contrast to conventional vertical bipolar transistor in which current across the base flows in the direction normal to the surface; l.t. features inferior characteristics as compared to vertical transistor.
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