What is contact resistance in semiconductor?
Contact resistance is a measure of the ease with which current can flow across a metal- semiconductor interface. In an ohmic interface, the total current density J entering the interface is a function of the difference in the equilibrium Fermi levels on the two sides.
What is a contact resistance test?
The electrical contact resistance test is used for switching devices, cable joints as well as other connections. It can measure either the voltage drop or the resistance offered by the contacts or resistance of the joints or connections. This test detects the resistance at the milli-ohm level or micro-ohm level.
What does contact resistance depend on?
The contact resistance depends on the surface roughness greatly, and the pressure holding the two surfaces together also influences the contact resistance. Thermal contact resistance decreases with decreasing surface roughness and increasing interface pressure.
How do you reduce contact resistance?
Throughout the years of graphene research, researchers have discovered various methods to reduce the contact resistance, including work- function engineering [29,30], ultraviolet ozone treatment [31,32], alteration of the device geometry [33,34], and improvement of the surface roughness of graphene .
What is contact resistance What are factors affecting the contact resistance?
The apparent contact pressure and the mean junction temperature, combined with the thermophysical and mechanical properties of the contacting materials and the surface characteristics, are the primary factors in determining the magnitude of the contact resistance.
How do you increase contact resistance?
Short Answer: Use water, salt water, bentonite, calcium chloride, foil pits, or all of the above where the ground contacts your electrodes. Try to get less than 5,000 ohms for contact resistance.
Does contact resistance increase with temperature?
Also, in the electrical contact pair dealing with a large current, the temperature of the con- tact increases due to the Joule heat of the contact resistance. This in turn causes the increase of the contact resistance and the softening and melting of the contact.
How do you overcome high contact resistance?
Tips on how to reduce contact resistance: Saltwater or Regular Water: For most purposes, soaking the ground underneath your stainless steel stakes with saltwater will work to improve contact resistance. A 2% saline solution should be fine. If saltwater is not available, non-saline water can also work.
What is one method for reducing the contact resistance between two materials?
The thermal contact resistance can be minimized by applying a thermally conducting liquid called a thermal grease such as CPU grease on the surfaces before they are pressed against each other.
What is the semiconductor resistance of the contact?
The semiconductor resistance is These results suggest a method for measuring the contact resistance. If resistors of several different lengths are constructed, keeping all other details the same, the total resistances of each can measured and plotted.
How to measure the contact resistance of a metal-semiconductor junction?
The first step in measuring the contact resistance of a metal-semiconductor junction is to deposit the metal on the semiconductor and pattern it so that you have lots of identical pads spaced varying distances apart. This is an example of the metal pattern. Ideally, the pattern includes many rows of various pad sizes.
What are contact resistance test structures?
Contact resistance test structures are usually fabricated with other conventional test devices on the same die or wafer to monitor a particular process.
Why do we measure contact resistance in transistors?
However, in transistors and other electronic devices, the contacts are a necessary part of the device, and it is useful to determine the contact resistance so that we can have some idea of how it might affect device performance. We can measure the contact resistance using an extension of the resistance techniques employed earlier.