Semiconductor device with STI structure and preparation method

Abstract

The invention provides a semiconductor device with an STI structure and a preparation method. The preparation method is that a reflecting wall is formed in the STI structure while the STI structure is formed; the reflecting wall can stop light reflecting to photoresist to cause excessive exposure during performing subsequent photoetching process for the semiconductor device with the STI structure, thus the photoresist can be kept in good appearance all the time, and a device with an ideal appearance can be prepared; meanwhile, an anti-reflection layer for assisting photoetching is not needed, so that the production cost can be reduced.

Description

technical field [0001] The invention relates to the field of semiconductor preparation, in particular to a semiconductor device with an STI structure and a preparation method. Background technique [0002] In the preparation process of semiconductor chips, STI (Shallow Trench Isolation, shallow trench isolation) plays a pivotal role. Because it can achieve high-density isolation, it is widely used in deep submicron devices and DRAM (Dynamic Random Access Memory, dynamic random access memory), etc. Manufacturing of high-density memory circuits, but as the critical dimensions of devices continue to shrink, problems also emerge. [0003] In some STI manufacturing processes, the side walls that make up the STI are generally inclined walls. At the same time, in the semiconductor manufacturing process, a complete process may require dozens of photolithography processes, such as the first patterning process to form After STI, another subsequent patterning process is required to pe...

Images