Semiconductor device

A semiconductor device, comprising:

• a semiconductor substrate comprising:
• a first portion located within a diode region;
• a second portion located within a guard ring region;
• and
• a third portion located within an internal circuit region;
• a first p-type well region, wherein at least a part of the first p-type well region is disposed in the first portion;
• a first n-type well region disposed in the second portion;
• a second p-type well region, wherein a part of the first n-type well region is located between the first p-type well region and the second p-type well region in a horizontal direction;
• a second n-type well region disposed in the third portion, wherein a part of the second p-type well region is located between the first n-type well region and the second n-type well region in the horizontal direction;
• and
• a deep n-type well region disposed in the semiconductor substrate, wherein the deep n-type well region is partly located under the first p-type well region, partly located under the first n-type well region, and partly located under the second p-type well region, and the deep n-type well region is separated from the second n-type well region.