Schottky diode having current leakage protection structure and current leakage protecting method of the same

A Schottky diode having a current leakage protection structure includes a Schottky diode unit, a first isolation portion and a second isolation portion. The Schottky diode unit is defined in a substrate and includes a metalized anode, an active region having dopants of first conductive type, a cathode and at least one isolation structure. The first isolation portion having dopants of second conductive type is formed between substrate and active region, and the first isolation portion includes a first well disposed beneath active region, and a first guard ring surrounding active region and connecting to the first well. The second isolation portion having dopants of first conductive type is formed between substrate and the first isolation portion, and the second isolation portion includes a second well disposed beneath the first well, and a second guard ring surrounding the first guard ring and connecting to the second well.