Semiconductor device with overvoltage protection and bidirectional polarity device based on it

Abstract

The invention relates to a semiconductor apparatus, and in particular relates to a semiconductor apparatus with overvoltage protection and a bidirectional polar device based on the apparatus. The invention is realized by the following scheme: the semiconductor apparatus with overvoltage protection comprises a substrate, a first area arranged on the substrate, a plurality of second areas arranged at the upper part of the first area, a third area arranged on the lower surface of the substrate, a first metal contact connected on the first area and the second area, and a second metal contact connected on the third area, a plurality of fluctuation areas are arranged at the junction of the lower surfaces of the substrate and the first area, and each fluctuation area corresponds to the middle of the second area. Compared with the background art, when the semiconductor apparatus is conducted, the current density of a PN knot close to the breakdown cathode and the cathode base region has difficulty in achieving the critical value endured by a semiconductor material, so that excess current endurance is improved, and the apparatus works more reliably.

Description

Technical field [0001] The invention relates to a semiconductor device, in particular to a semiconductor device with overvoltage protection and a bidirectional polar device based on the device. Background technique [0002] Known semiconductor devices with overvoltage protection have a lower breakdown voltage region located close to the junction between the adjacent cathode base region and the anode base region, as described in the US Patent No. 4,282,555 of P. Svedberg A low-voltage protection method for semiconductor devices is disclosed. [0003] This region has the same conductivity type as the cathode base region, but has a higher doping concentration than the cathode base region, and due to the high doping concentration of this region, the electric field strength of the PN junction between this region and the adjacent anode base region is higher than The electric field strength of the PN junction at the junction of the anode base region and the cathode base region, therefore...

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Problems solved by technology

[0006] It can be seen that during the conduction process of this kind of device, the PN junction current density between each N+ type region 3 and P type region 2 is not uniform, and the conduction first occurs in the N+ type region closest to the P+ type region 2 5 At the boundary of -3, the PN junction current density between the N+-type region-3 and the P-type region-2 will easily and quickly reach the critical value that the semiconductor material can withstand, resulting in device damage

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