Semiconductor structure, method for forming the same and method for suppressing hot cluster

A semiconductor structure for suppressing a hot cluster, comprising:

• a substrate of a first dopant concentration;
• an epitaxial layer disposed on and directly contacting said substrate, and having a second dopant concentration smaller than said first dopant concentration;
• a dopant gradient region disposed in said epitaxial layer and having a dopant gradient decreasing from said substrate to said epitaxial layer;
• a first element region disposed in said epitaxial layer and comprising a first element doping region and a first element;
• a second element region disposed in said epitaxial layer and comprising a second element doping region and a second element;
• and
• a shallow trench isolation region disposed between said first element region and said second element region, and comprising a shallow trench isolation completely disposed inside said shallow trench isolation region, wherein said shallow trench isolation region is substantially adjacent to said dopant gradient region to suppress a hot cluster formed by said first element region jeopardizing said second element region.