Schottky (Schottky) diode is the metal layer is deposited in a thin epitaxial layer of N-type silicon, using the contact between the metal and semiconductor barrier can be obtained a one-way conductive effect equivalent to the PN junction. The contact surface is called the metal semiconductor junction. The full name of the Schottky diode is a Schottky barrier diode (Schottky Barrier Diode, SBD). Most Schottky diodes are semiconductor materials, new materials, silicon carbide (SiC) SBD has been applied with silicon (51).

1) the characteristics of the silicon SBD

Forward voltage drop than the PN junction diode is low, about 1/2 to 1/3, the typical value of 0.45 ~ 0.55V, the novel low voltage can be as low as 0.32V; reverse voltage is low, in the several tens of volts more (up to 200 V), suitable for low-voltage circuits.

2) silicon SBD shutdown speed

Silicon MD off fast, belongs to the fast recovery diode, the rectifying action depends only on the drift phenomenon of majority carriers, no excess minority carriers, without memory effect, there is no forward and reverse recovery phenomenon, the trr only barrier capacitance charging, discharge time, so Functional smaller than that of the same rated junction diode, but with the reverse di / dt contents. Reverse recovery time the trr of approximately 10ns magnitude.

3) The disadvantage of silicon SBD

The disadvantage of the silicon of the SBD is the reverse leakage current is much larger than the junction type diode, the junction capacitance is also large.

4) silicon carbide Schottky diode

Silicon carbide Schottky diode maximum reverse voltage can reach 2200V; 600V, 1200V, 1700V products have been seen on the market, the forward voltage drop of about 1V.