Semiconductor structure and method of forming the same

Abstract

The application provides a semiconductor structure and a forming method thereof. The method comprises the following steps: providing a semiconductor substrate, which comprises a device region and an alignment region; sequentially forming a pad oxide layer, a sacrifice layer and an anti-reflection layer on the surface of the semiconductor substrate; etching the pad oxide layer, the sacrifice layer and the anti-reflection layer into the semiconductor substrate to simultaneously form a groove in the device region and the alignment region; forming an oxide layer on the sidewall and the bottom of the groove and performing an annealing process on the oxide layer; forming an isolation material layer in the groove and on the surface of the anti-reflection layer; grinding and removing part of the isolation material layer by using a first chemical mechanical polishing process; grinding the isolation material layer to the anti-reflection layer by using a second chemical mechanical polishing process; etching and removing the anti-reflection layer, part of the sacrifice layer and the isolation material layer higher than the sacrifice layer to form an isolation structure in the device region.

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