Trench oxide recess

Isolation Deep trench shallow trench or recessed oxide... 

For an ILD (interlayer dielectric, a part (initial step height)) is poUshed to reduce the unevenness of the height. The remaining step height shows planarity performance. Since W-Plug, STI (shallow trench isolation), and Cu interconnect are so-called recess processes, the remaining oxide erosion and dishing show planarity performance. 

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