Introduction:
A Schottky diode is a type of diode that is formed by the junction of a metal with a semiconductor. It is named after the German physicist Walter H. Schottky. Unlike a regular p-n junction diode, a Schottky diode is formed by a metal-semiconductor junction, which makes it different in terms of its characteristics and behavior.

Explanation:
The silicon used in a Schottky diode is usually of N-type. This means that it is doped with impurities that introduce free electrons into the silicon lattice, giving it an excess of negative charge carriers.

Reasons:
There are several reasons why N-type silicon is commonly used in Schottky diodes:

1. Efficient Barrier Formation: The metal-semiconductor junction in a Schottky diode forms a barrier that controls the flow of current. N-type silicon provides a more efficient barrier formation due to its higher electron concentration.

2. Lower Forward Voltage Drop: The forward voltage drop across a Schottky diode is typically lower compared to a p-n junction diode. This is because the metal-semiconductor junction has a smaller voltage drop than the p-n junction. N-type silicon facilitates a lower forward voltage drop, making it suitable for high-speed and low-power applications.

3. Faster Switching Speed: The absence of a p-n junction in a Schottky diode allows for faster switching speeds. N-type silicon, with its high electron concentration, enables faster charge carrier movement and facilitates quicker switching transitions.

4. Reduced Reverse Recovery Time: The reverse recovery time of a Schottky diode is significantly shorter than that of a p-n junction diode. This is advantageous in applications where fast switching is required. N-type silicon contributes to this reduced reverse recovery time.

5. Compatibility with Metal Contacts: N-type silicon is compatible with a wide range of metal contacts, making it suitable for the metal-semiconductor junction in a Schottky diode.

Conclusion:
In conclusion, the silicon used in a Schottky diode is usually of N-type. This choice is based on the advantages offered by N-type silicon, such as efficient barrier formation, lower forward voltage drop, faster switching speed, and reduced reverse recovery time. These characteristics make N-type silicon an ideal choice for Schottky diodes in various electronic applications.