How do you calculate specific contact resistance?

How do you calculate specific contact resistance?

Specific contact resistance can be obtained by multiplying by contact area. It should also be noted that the contact resistance may vary with temperature. Inductive and capacitive methods could be used in principle to measure an intrinsic impedance without the complication of contact resistance.

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 kind of metal contact should be used to measure the resistance of a semiconductor?

Contact Resistance can be measured using transmission line method. Getting an ohmic contact could be easier for elemental semiconductors. But for compound semiconductors getting “true ohmic contact” is a serious issue.

What is semiconductor ohmic contact?

The Ohmic contact is a low resistance junction (non-rectifying) provides current conduction from metal to semiconductor and vice versa. Theoretically speaking the current should increase/ decrease linearly with the applied voltage.

What do you mean by contact resistance?

Contact resistance is the resistance to current flow, due to surface conditions and other causes, when contacts are touching one another (in the closed condition of the device).

How do you test contact resistance?

This involves injecting a fixed current, usually around 100A, 200A and 300 A through the contacts and measuring the voltage drop across it. This test is done with a special contact resistance measuring instrument. Then, using Ohm’s law, the resistance value is calculated.

What is meant by contact resistance?

What is difference between ohmic contact and Schottky contact?

Schottky Contacts make good diodes, and can even be used to make a kind of transistor, but for getting signals into and out of a semiconductor device, we generally want a contact that is Ohmic. Ohmic contacts conduct the same for both polarities. (They obey Ohm’s Law).

Why ohmic contact is necessary in semiconductor devices?

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. This article focuses on metal–semiconductor ohmic contacts.

What is the purpose of ohmic contact?

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.

What is acceptable value of contact resistance?

We generally recommend trying to get less than 5,000 ohms for contact resistance—though we often recommend trying to get less than 1,800 ohms if possible.

What do you mean by Schottky contact?

The rectifying contact that occur between a metal and a lightly doped semiconductor.