Patent ID: 11342217

Abstract:
The present disclosure provides a method for improving HDP filling defects through an STI etching process, comprises a wafer uniformly distributed with pixel areas and logical areas, and dividing the wafer into quadrants 1 to 4; placing the second quadrants in an etching chamber in a manner of facing to a cantilever of an etching machine; etching the wafer to form STI areas with the same depth in the pixel areas and the logical areas of the quadrants 1 to 4; removing the wafer from the etching machine and covering the STI areas of the pixel areas with a photoresist; placing the wafer on an electrostatic chuck of the etching chamber again, and enabling any quadrant except the second quadrant to face to the cantilever; continuously etching the STI areas of the logical areas of the quadrants 1 to 4 to form deep STI areas.