Wall embedding type shallow groove isolation structure and method for forming same

Abstract

The invention provides a recessed shallow slot isolation structure which comprises a substrate internally provided with a slot which is filled by a linear oxide layer and a shallow slot isolation oxide in sequence and divided into a high-pressure area and a low-pressure area, wherein, high-pressured grid oxide grows in the high-pressure area, and a slot-shaped structure is formed in the shallow slot isolation oxide at the edge of the active area where the high-pressured grid oxide grows. The invention also provides a method for forming the structure. The invention has the advantages of effectively improving the thinning problem of the high-pressured grid oxide at the upper edge of the active area, simultaneously ensuring that the low-pressure area maintains normal step height, enhancing the reliability of the high-pressure grid oxide, and relieving the parasitic transistor problem. The method can be used for the development and the application of deep submicron high-pressure advancement in the future.

Description

technical field [0001] The invention relates to a semiconductor element, in particular to a wall-embedded shallow trench isolation structure and a forming method thereof. Background technique [0002] In the current sub-micro high-voltage process technology, shallow trench isolation technology is used for isolation between high-voltage devices, but when high-voltage devices use thicker gate oxides, in order to maintain low voltage without leakage, a fixed step height is often maintained , so that serious problems arise at the edge of the groove. A new isolation structure is needed that not only improves the problem of gate oxide thinning in high-voltage devices, but also maintains normal step heights in low-voltage regions. Contents of the invention [0003] Due to the above-mentioned deficiencies of the prior art, there is an urgent need for a structure and method that does not cause thinning problems at the edges of the groove. [0004] In view of the above purpose, th...

AI Technical Summary

Problems solved by technology

[0002] In the current sub-micro high-voltage process technology, shallow trench isolation technology is used for isolation between high-voltage devices, but when high-voltage devices use thicker gate oxides, in order to maintain low voltage without leakage, a fixed step height is often maintained , so that serious problems arise at the edge of the groove

Images