Device array of silicon carbide gate turn-off thyristor GTO and preparation method thereof

Abstract

The invention provides a device array of a silicon carbide gate turn-off thyristor GTO and a preparation method thereof, wherein each single device is relatively small in size. The device array is formed by photoetching according to a corresponding photoetching layout and comprises at least two array structures of silicon carbide gate turn-off thyristors. The gate electrode of a GTO device unit islocated in the center of the table surface of the device unit. The gate electrode of the GTO device unit forms an interdigital structure together with anodes located on the two sides of the table surface of the device unit. A cathode is located on the back surface of the substrate of the device unit. During the packaging process, the gate electrodes of all device units are led down to a packagingstructure according to the layout design. Meanwhile, all anodes are led out in the opposite directions of the gate electrodes. According to the device array scheme adopted by the invention, the effective working area of a whole packaging chip can be remarkably improved. The condition that the performance of the whole packaging chip is reduced due to the defects of local materials can be avoided.Moreover, the process difficulty of device machining can be reduced, and the process stability and the process uniformity can be improved. The yield of prepared devices can be remarkably improved.

Description

technical field [0001] The invention relates to a silicon carbide gate turn-off thyristor GTO device array and a preparation method thereof, belonging to the technical field of semiconductor power electronic devices. Background technique [0002] Silicon carbide (SiC) material, as a new type of wide bandgap semiconductor material, has a series of excellent material properties. These characteristics include large band gap, high critical breakdown field strength, high electron saturation drift velocity, radiation resistance and normal operation at higher temperatures; in addition, the current epitaxial growth technology of silicon carbide materials is relatively It is also more mature than other common wide bandgap semiconductors. These factors together determine that SiC material is the preferred material for preparing various types of advanced power devices. [0003] Since the critical breakdown field strength of SiC is almost ten times that of Si, when preparing power dev...

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Problems solved by technology

These material defects have a significant negative impact on the withstand voltage capability of GTO devices

Due to the objective existence of material defects, no matter how the terminal structure design of large-scale devices is optimized, premature breakdown of devices caused by internal defect-assisted tunneling leakage is inevitable, which will significantly reduce the blocking voltage level of devices

However, in order to meet the requirements for the large current carrying capacity of GTO devices in practical applications, SiC GTO devices must continue to try to increase the device area

It is precisely the existence of such contradictions that the GTO device always needs to constantly compromise between device performance and device area during the design process, and the super-large size (1cm 2 and above) device development is very difficult, which significantly affects the further development of SiC GTO device itself and the potential application fields in the future

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