High-voltage trench junction barrier Schottky diode

摘要

In a Schottky diode having an n+-type substrate, an n-type epitaxial layer, at least two p-doped trenches introduced into the n-type epitaxial layer, mesa regions between adjacent trenches, a metal layer functioning as a cathode electrode, and another metal layer functioning as an anode electrode, the thickness of the epitaxial layer is more than four times the depth of the trenches.

主权项

1. A Schottky diode, comprising:
an n+substrate; an n-epitaxial layer having a thickness D epi; at least two trenches introduced into the n-epitaxial layer, each trench having a width Wt and a depth Dt; mesa regions each having a width Wm, wherein each mesa region is provided between two adjacent trenches; a metal layer functioning as a cathode electrode on the rear side of the n+substrate of the Schottky diode; and a metal layer functioning as an anode electrode on the front side of the Schottky diode, the metal layer forming an ohmic contact with the trenches and a Schottky contact with the n-epitaxial layer; wherein:
the following equation holds for the depth Dt of the trenches and the thickness D_epi of the n-epitaxial layer: K·Dt4;the following equation holds for the ratio of the depth Dt of the trenches to the width Wm of the mesa regions: Dt/Wm≧2; andthe following relationship holds: NA·Wt>>ND·Wm, where NA is the doping concentration of the trenches, Wt is the width of each of the trenches, ND is the doping concentration of the n-epitaxial layer, and Wm is the width of the mesa region between two trenches.