Low defect metrology approach on clean track using integrated metrology

A method for on-track monitoring of defects on a wafer before subjecting the wafer to resist processing comprising:

• introducing a pre-resist coat wafer structure into a device fabrication system in order to yield a device product, the wafer structure having a front side and back side;
• monitoring at least one of the front side and the back side of the wafer structure for defects before a photoresist layer is formed on the wafer structure;
• measuring the defects found on the wafer structure in order to obtain defect information relating to the defects found on the wafer structure:
• comparing the defect information with threshold defect limits;
• and cleaning at least one of the front side and the back side of the wafer structure to reduce the defects found on that side of the wafer structure prior to forming a photoresist layer over the front side of the wafer structure, wherein cleaning the front side of the wafer is performed independently of cleaning the back side of the wafer.

An online method for real-time pre-resist coat and post-resist coat inspection of a wafer for defects comprising:

• providing a pre-resist coat wafer structure, the wafer structure having a front side surface and a back side surface;
• inspecting at least one of the front side surface and the back side surface of the pre-resist coat wafer structure for defects;
• measuring the defects found on the pre-resist coat wafer structure in order to obtain defect information relating to the defects found on the wafer structure;
• cleaning at least one of the front side and the back side of the wafer structure to reduce the defects found on that side of the pre-resist coat wafer structure when the measured defects on that side are greater than me threshold defect limits;
• forming a photoresist layer over the front side of the pre-resist coat wafer structure to create a resist-coated wafer structure;
• inspecting the back side of the resist-coated wafer structure for defects without adversely affecting the front side of the resist-coated wafer structure;
• cleaning the back side of the resist-coated wafer structure to remove any defects found thereon;
• and
• patterning the resist-coated wafer structure to thereby form one or more features in the wafer structure.