A Schottky diode and its manufacturing method

Abstract

An embodiment of the invention discloses a Schottky diode and a manufacturing method thereof. The method comprises the following steps of forming a bowl-shaped opening on a barrier layer which is implanted as a P well on a front side of a wafer; and using the bowl-shaped opening as a mask layer window and implanting ions used for forming the P well. Because the mask layer window which is implanted as the P well ions is the bowl-shaped opening, the P well can be formed through an ion implantation technology and a high temperature knot pushing technology is omitted. Compared to the high temperature knot pushing, the ion implantation is controllable so that a size of the widest position of the formed P well is accurate and a low VF is acquired. Besides, the high temperature knot pushing technology is omitted so that stability of the schottky diode is increased. Further, a silicide is used to replace traditional polycrystalline silicon to make an induction grid. Because a barrier where metal and silicon are contacted is very low, an electron capturing capability of the induction grid to a channel formed by the P well and N+ is increased so that a grid voltage needed by inversion of the channel formed by the Schottky diode P well and the N+ is reduced and the VF is decreased.

Description

technical field [0001] The invention relates to the field of semiconductor devices and their manufacturing techniques, in particular to a Schottky diode and a manufacturing method thereof. Background technique [0002] Schottky diodes are essential supporting devices in high-frequency circuits, and are widely used in voltage regulators, rectifiers, inverters, uninterrupted power supplies (Uniterrupted Power Supply, UPS) and other circuits. [0003] In Schottky diode manufacturing technology, in order to obtain excellent electrical properties, a P well is usually used to form a protective junction to reduce the reverse leakage current of the device. Such as figure 1 As shown, it is a schematic diagram of a conventional self-aligned implant push-junction process, and a steep opening is etched on the gate region 103 as a barrier layer 104 for P-well implantation. Using the steep opening as a mask window, ion implantation is performed, and high-temperature push junction is per...

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Problems solved by technology

[0005] The purpose of the embodiments of the present invention is to provide a Schottky diode and a manufacturing method thereof, so as to solve the following problems in the manufacturing process of the Schottky diode in the prior art: when forming the P-well, high-temperature pushing junction is used, which reduces the stability of the device , and the size control of the widest part of the P-well is not precise, and the VF cannot be reduced

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