Method for manufacturing silicon carbide SBD device and front protecting method of device

Abstract

The invention discloses a method for manufacturing a silicon carbide SBD device and a front protecting method of the device. The method comprises the steps that a diamond-like film is arranged on an oxidation layer of the front of a silicon carbide wafer; an oxidation layer on the back of the silicon carbide wafer is removed; an ohmic contact is manufactured on the back of the silicon carbide wafer; a window is etched in the front of the silicon carbide wafer; an ohmic contact is manufactured on the front of the silicon carbide wafer. According to the method, as the diamond-like film has higher corrosion resistance and rigidity, the front can be protected against corrosion or scratch; in the film forming process, film forming substances will not be left on the back of the wafer so that the reliability of the ohmic contacts can be improved and the device yield can be increased; in addition, the diamond-like film can be directly used as a passivation layer of the device, and does not need to be removed, so that the working procedures are reduced.

Description

technical field [0001] The invention relates to the technical field of manufacturing high-power devices, in particular to a method for manufacturing a silicon carbide SBD device and a front protection method thereof. Background technique [0002] Silicon carbide devices have high withstand voltage capacity, low on-resistance and good thermal conductivity, and are widely used in the fields of power electronic systems of aviation, aerospace and ships, as well as high-frequency and high-speed work fields. Among them, since the low specific contact resistance of ohmic contacts is one of the important factors determining the performance of devices, making ohmic contacts is an important process in the production of silicon carbide devices. In the process flow of silicon carbide SBD (Schottky barrier diode) devices, an oxide layer will be formed on the front side of the wafer through the sacrificial oxidation of silicon carbide itself as a passivation layer to improve the device wi...

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Problems solved by technology

[0004] However, due to the low hardness of the photoresist protective film, this method cannot guarantee that the front oxide layer will not be scratched, and the protection effect is limited, and the photoresist is easily splashed to the back of the wafer during the spin coating process, which seriously affects metal sputtering. The effect of the surface treatment on the back of the front wafer affects the specific contact resistance, and also reduces the reliability of the ohmic contact and the yield of the device. In addition, if the photoresist is not completely removed after the surface treatment, it will affect the performance of the device. Therefore, for photolithography Glue removal also adds to the complexity of the process

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