Method and system for nondestructive layer defect detection

Abstract

A method for nondestructive layer defect detection includes projecting radiation such as a laser beam on a surface of the layer. The surface of the layer is heated by the projected radiation so as to melt at least a portion of the layer. An impurity contained in a defect is heated by the projected radiation so as to increase the pressure of the material within the defect sufficiently to cause the impurity to emerge from the defect through the surface of the layer. The layer is then scanned for a visible defect created by the emergence of the impurity from the defect. A wafer scanning system for nondestructive layer defect detection includes a radiation source such as a laser and a wafer support system that supports a semiconductor wafer with a layer formed thereon in alignment with the radiation source. A control system causes the radiation source to project radiation on a surface of the layer sufficiently to (a) melt at least a portion of The layer, (b) heat the contents of any defect formed in the layer, and (c) cause the contents of the defect to erupt from the surface of the layer. The method and system for nondestructive layer defect detection allow hidden defects created in the formation of a layer to be detected without adversely affecting the features underlying the layer in question. A semiconductor wafer in which defects have been detected may therefore be reworked to remove and re-deposit the defective layer, giving considerable cost savings in integrated circuit chip production.