Schottky Diode Operation Pdf

That means the anode is connected to the p side and cathode is connected to the n side. This Schottky barrier results in both very fast switching and low forward voltage drop.

The work function is different for metal and semiconductor. The turn on voltage for schottky diode is very small as compared to the P-N junction diode. Here is a question for you, what is the main function of Schottky diode? Schottky barrier diode is an extension of the oldest semiconductor device that is the point contact diode.

It has a low forward voltage drop and a very fast switching action. The Schottky diode is named after the scientist Schottky.

Typical metals used are molybdenum, platinum, chromium or tungsten, and certain silicides e. The value of this barrier height depends on the combination of semiconductor and metal. We know that when a neutral atom loses an electron it becomes a positive ion similarly when a neutral atom gains an extra electron it becomes a negative ion.

The V-I characteristics of schottky diode is almost similar to the P-N junction diode. If this current is not limited by an external resistance connected to the diode circuit, the diode may permanently be destroyed.

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Thus, this is all about Schottky Diode Working and its working principle and applications. Schottky barrier is a depletion layer formed at the junction of a metal and n-type semiconductor. As long as this guard ring diode is not forward biased, it adds only capacitance.

The vacuum level is defined as the energy level of electrons that are outside the material. The energy band diagram of the metal and n-type semiconductor after contact is shown in the below figure.

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However, it serves as a distributed ballasting resistor over the entire area of the junction and, under usual conditions, prevents localized thermal runaway. Holes carry negligible electric current. High current density We know that the depletion region is negligible in schottky diode. When a reverse bias voltage is applied to the schottky diode, the depletion width increases. Below a certain width, the charge carriers can tunnel through the depletion region.

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In higher voltage Schottky devices, in particular, the guard ring structure needed to control breakdown field geometry creates a parasitic p-n diode with the usual recovery time attributes. With increased doping level of the semiconductor the width of the depletion region drops. This capacitance is present at the junction of the diode. What is a schottky barrier?

So it is known as junction capacitance. The conduction band electrons or free electrons that are crossing the junction will provide extra electrons to the atoms in the metal.

When the metal is joined with the n-type semiconductor, a device is created known as schottky diode. In schottky diode, the depletion region is absent or negligible, isothermal forging pdf whereas in p-n junction diode the depletion region is present.

Energy band diagram of schottky diode The energy band diagram of the N-type semiconductor and metal is shown in the below figure. The metal-semiconductor junction can be either non-rectifying or rectifying.

Therefore, the schottky diode consumes less voltage to turn on. In unbiased schottky diode, only a small number of electrons will flow from n-type semiconductor to metal. Potentiometer digital Variable capacitor Varicap. We know that electrons in the higher energy level have more potential energy than the electrons in the lower energy level. The built-in-voltage is the barrier seen by the conduction band electrons of the n-type semiconductor when trying to move into the metal.

The Schottky diode operates only with majority carriers. There are no minority carriers and thus no reverse leakage current as in other types of diodes. The amplitude of this current is very small as the number of minority charge carriers in the diode is very small. When sufficient forward voltage is applied, a current flows in the forward direction. So a schottky diode has a very low capacitance.

This sudden rise in electric current causes depletion region to break down which may permanently damage the device. High efficiency Schottky diodes operate at high frequencies. The cat's-whisker detectors used in the early days of wireless and metal rectifiers used in early power applications can be considered primitive Schottky diodes.

Schottky barrier diode Operation & Characteristics

Metal-semiconductor M-S junction is a type of junction formed between a metal and an n-type semiconductor when the metal is joined with the n-type semiconductor. It decreases and increasing temperature doping concentration in N type semiconductor. The non-rectifying metal-semiconductor junction forms a non-rectifying schottky barrier.

The huge number of such generated charge carriers would contribute a huge reverse current in the diode. Since the metal has a sea of free electrons, the width over which these electrons move into the metal is negligibly thin as compared to the width inside the n-type semiconductor. When a p-type semiconductor is joined with an n-type semiconductor, a junction is formed between the P-type and N-type semiconductor.

Schottky Diode Working and Its Applications

Schottky Diode Working and Applications

Schottky Diode Working and Applications

How was Schottky Diode Discovered