An ohmic contact is a non-rectifying electrical junction: a junction between two conductors that has a linear current–voltage (I–V) curve as with Ohm's law. Low-resistance ohmic contacts are used to allow charge to flow easily in both directions between the two conductors, without blocking due to rectification or excess power dissipation due to voltage thresholds.
By contrast, a junction or contact that does not demonstrate a linear I–V curve is called non-ohmic. Non-ohmic contacts come in a number of forms, such as p–n junction, Schottky barrier, rectifying heterojunction, or breakdown junction.
Generally the term "ohmic contact" implicitly refers to an ohmic contact of a metal to a semiconductor, where achieving ohmic contact resistance is possible but requires careful technique. Metal–metal ohmic contacts are relatively simpler to make, by ensuring direct contact between the metals without intervening layers of insulating contamination, excessive roughness or oxidation; various techniques are used to create ohmic metal–metal junctions (soldering, welding, crimping, deposition, electroplating, etc.). This article focuses on metal–semiconductor ohmic contacts.
Stable contacts at semiconductor interfaces, with low contact resistance and linear I–V behavior, are critical for the performance and reliability of semiconductor devices, and their preparation and characterization are major efforts in circuit fabrication. Poorly prepared junctions to semiconductors can easily show rectifying behaviour by causing depletion of the semiconductor near the junction, rendering the device useless by blocking the flow of charge between those devices and the external circuitry. Ohmic contacts to semiconductors are typically constructed by depositing thin metal films of a carefully chosen composition, possibly followed by annealing to alter the semiconductor–metal bond.
By contrast, a junction or contact that does not demonstrate a linear I–V curve is called non-ohmic. Non-ohmiccontacts come in a number of forms, such...
its Schottky barrier being too low, is called an ohmiccontact. When a metal is put in direct contact with a semiconductor, a so called Schottky barrier...
rectifier any more and becomes an ohmiccontact. This can be used for the simultaneous formation of ohmiccontacts and diodes, as a diode will form between...
rectangle an appropriate geometric factor is added. Bus bars must make ohmiccontact. Inductive measurement is used as well. This method measures the shielding...
have ohmiccontacts. Inductive and capacitive methods could be used in principle to measure an intrinsic impedance without the complication of contact resistance...
gold-germanium alloy (sometimes with nickel) is used to achieve low contact resistance; an ohmiccontact is formed by diffusion of germanium, forming a thin, highly...
to facilitate an ohmiccontact, which are placed on the contact layers after exposure by photolithography and etching. The contact layer underneath the...
process conditions that do not satisfy this requirement, for example, ohmiccontact formation for source/drain regions of transistors necessitates introduction...
diffusion to make an n+ ohmiccontact, and boron implantation to make a p+ contact. Coaxial detectors with a central n+ contact are referred to as n-type...
electrical contact allowing the local resistivity to be determined. The probes produce a negligible probe to silicon resistance (nearly ohmiccontact) over...
. This linear region of operation is called ohmic (or sometimes triode) ... Beyond the knee of the ohmic region, the curves become essentially flat in...
tribocharging) describes electric charge transfer between two objects when they contact or slide against each other. It can occur with different materials, such...
semiconductor in the center makes a Schottky barrier against one metal electrode (providing rectifying action) and an ohmiccontact with the other electrode....
determine the specific contact resistivity when the metal-semiconductor junction shows ohmic behaviour. In this case the contact resistivity ρ C {\displaystyle...
either rectifying or non-rectifying. Non-rectifying junctions comprise ohmiccontacts, which are characterised by a linear current–voltage ( I − V {\displaystyle...
solar cells and perovskite solar cells, especially when forming an ohmiccontact to organic semiconductors. Haynes, p. 4.77 Balendhran, Sivacarendran;...
constant. This relationship is called Ohm's law, and materials which obey it are called ohmic materials. Examples of ohmic components are wires and resistors...
electrodes in ohmiccontact with the silicon. Some companies use an additional electroplating step to increase efficiency. After the metal contacts are made...
Joule heating (also known as resistive, resistance, or Ohmic heating) is the process by which the passage of an electric current through a conductor produces...
Polysilicon may also be employed as a resistor, a conductor, or as an ohmiccontact for shallow junctions, with the desired electrical conductivity attained...
is in direct contact with silicon, hence, the process is self-aligned. It is commonly implemented in MOS/CMOS processes for ohmiccontacts of the source...
Electromagnetic compatibility Electromagnetic interference Galvanic isolation Ohmiccontact Alexander, Charles K.; O. Sadiku, Matthew N. (2013). Fundamentals of...
n-type regions are typically heavily doped because they are used for ohmiccontacts. The wide intrinsic region is in contrast to an ordinary p–n diode....
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