Countertop type semiconductor device and manufacturing method thereof

Abstract

The invention provides the manufacturing method of a countertop type semiconductor device. The countertop type semiconductor device comprises an N+-type semiconductor substrate, an N-type semiconductor layer which is bonded to the surface of the N+-type semiconductor substrate, a P+-type semiconductor layer which is bonded to the surface of the N-type semiconductor layer and forms a PN junction part with the N-type semiconductor layer, first trenches which reach the inside N-type semiconductor layer from the surface of the P+-type semiconductor layer, a passivation layer which is filled in the first trenches, a second trench which is located between two adjacent first trenches, a passivation film which is arranged on the surface of the second trench, and a metal layer which is formed on the surface of the P+-type semiconductor layer and the N+-type semiconductor substrate. According to the invention, external impurities can be well blocked; cracking and microcracks are suppressed; a better passivation performance can be acquired; and high performance and high reliability can be realized.

Description

technical field [0001] The invention relates to the technical field of semiconductor devices, in particular to a mesa semiconductor device and a manufacturing method thereof. Background technique [0002] In the previous mesa-type (Mesa-type) semiconductor devices, the following known methods for forming passivation layers and metal layers, such as knife scraping method, electrophoresis method, photoresist glass method, CVD, etc., are all used to complete the PN A narrow groove is etched out of the wafer fabricated by the junction, and a single-layer or multi-layer insulating film such as glass is coated or sintered on the groove wall to form a passivation layer, and then electrodes are fabricated on the surface of the semiconductor layer. Glass is a kind of brittle material. The thickness of the glass formed by these methods is mostly uneven, and when it is subsequently cut into a single chip, the glass layer is a brittle material that is prone to micro-cracks at the cut se...

AI Technical Summary

Problems solved by technology

Glass is a kind of brittle material. The thickness of the glass formed by these methods is mostly uneven, and when it is subsequently cut into a single chip, the glass layer is a brittle material that is prone to micro-cracks at the cut section; the glass passivation layer of the mesa semiconductor device in the past Located on the outermost side of the chip, it is vulnerable to damage such as collisions, which can also cause microcracks

These cracks will gradually expand during use, affecting the PN junction and even the entire chip, resulting in reduced device life or rapid failure

In addition, when the metal layer is formed by electroplating, etc., it is easy to attach metal to the passivation layer. Because the passivation layer is thin, it affects the electric field distribution of the PN junction and the ESD resistance of the device, reducing the reliability of the device.

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