The cross-sectional view of a transistor employing a Schottky barrier diode clamped between its base and collector regions is shown in figure. The equivalent circuit and the symbolic representation of the Schottky transistor are shown in figure. The Schottky diode is formed by allowing aluminium metallization for the base lead which makes contact with the N-type collector region also as shown in figure.
When the base current is increased to saturate the transistor, the voltage at the collector C reduces and this makes the diode Ds conduct. The base to collector voltage reduces to 0.4V, which is less the cut-in-voltage of a silicon base-collector junction. Therefore, the transistor does not get saturated.
