SEMICONDUCTOR STRUCTURE WITH JUNCTION LEAKAGE REDUCTION

摘要

A semiconductor structure is provided, which includes a semiconductor substrate, a first well region, a second well region, an active region, a shallow trench isolation (STI) and at least one deep trench isolation (DTI). The first well region of a first conductive type is on the semiconductor substrate. The second well region of a second conductive type is on the semiconductor substrate and adjacent to the first well region. The second conductive type is different from the first conductive type. The active region is on the first well region. The active region has a conductive type the same as the second conductive type of the second well region. The STI is between the first and second well regions. The DTI is below the STI. The DTI is disposed between at least a portion of the first well region and at least a portion of the second well region.

主权项

1. A method of forming a semiconductor structure, comprising:
providing a semiconductor substrate; forming a shallow trench by etching the semiconductor substrate; forming a protective layer covering the shallow trench; performing a first etching process to the protective layer until at least a portion of a bottom surface of the shallow trench is exposed by the protective layer; performing a second etching process on the portion of the bottom surface of the shallow trench, thereby forming at least one deep trench below the bottom surface of the shallow trench; removing the protective layer remained on the semiconductor substrate and in the shallow trench; filling an isolation oxide into the deep trench and the shallow trench to form at least one deep trench isolation (DTI) and a shallow trench isolation (STI) respectively; forming a first well region of a first conductive type on the semiconductor substrate; forming an active region on the first well region; and forming a second well region of a second conductive type on the semiconductor substrate and adjacent to the first well region, wherein the second conductive type is different from the first conductive type, and second conductive type is the same a conductive type of the active region; wherein the first well region and the second well region are formed such that the DTI is disposed between at least a portion of the first well region and at least a portion of the second well region.