A device structure and implementation method for improving the reverse breakdown voltage of gan L-FER

Abstract

The invention discloses a device structure for increasing the reverse breakdown voltage of GaN L-FER and a manufacturing method thereof. The structure includes a substrate, a GaN or AlN buffer layer, an intrinsic GaN channel layer, and an intrinsic AlGaN barrier layer , dielectric passivation layer, anode double Schottky contact and cathode ohmic contact. Epitaxially grow AlGaN / GaN heterojunction material on the substrate, and form ohmic contact and planar isolation on the structure, further form the anode structure of double Schottky contact, and finally deposit the passivation layer to realize the passivation of the device. The present invention utilizes the anode structure of double Schottky contacts, and the Schottky contacts have a certain shielding effect on the high voltage in the reverse breakdown process, thereby reducing the injection from the anode to the cathode through the device channel barrier layer or buffer layer. leakage current, which in turn increases the reverse breakdown voltage of the device. The implementation method of the invention is simple, and the reverse breakdown voltage of the GaN L-FER can be greatly improved so as to broaden its application in the field of power electronics.

Description

technical field [0001] The invention belongs to the technical field of microelectronics and relates to the manufacture of GaN power electronic devices Background technique [0002] In recent years, gallium nitride materials have attracted widespread attention due to their good properties such as large band gap, strong breakdown electric field, high thermal conductivity, and high saturation velocity. The extremely high-concentration two-dimensional electron gas formed by the strong polarization effect of AlGaN / GaN heterojunction in gallium nitride materials plays an important role in the field of high-speed, high-power and withstand voltage electronic devices. [0003] Rectification characteristics play an important role in electronic systems. As a multi-sub-device, GaN lateral field effect rectifier (L-FER) has a fast response speed and has broad application prospects. However, despite its good material properties and heterojunction properties, the reverse breakdown voltage...

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Problems solved by technology

[0005] At present, the main methods to improve the reverse breakdown voltage of GaN L-FER are: 1. Increase the length of the anode gate to suppress the DIBL effect, but the channel below the anode gate of L-FER is normally off, and the extension of the normally off channel will inevitably increase The on-resistance of the diode affects its forward current characteristics; 2. Add a normally-on channel to the short-channel device. In the case of reverse bias, the normally-on channel can share the reverse voltage applied to the normally-off channel. Bias voltage, this method can suppress the reverse leakage and increase the breakdown voltage but increases the size of the rectifier tube, and the increase in capacitance leads to a decrease in response speed

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