Systems and methods for detecting watermark formations on semiconductor wafers
Systems and methods for detecting watermark formations on semiconductor wafers are described. In one embodiment, a method comprises providing a semiconductor wafer having at least one watermark sensitive region fabricated thereon, subjecting the wafer to a wet processing step, enhancing a susceptibility to detection of at least one watermark formation created on the at least one watermark sensitive region, and detecting the at least one watermark formation. In another embodiment, a method comprises growing a first oxide layer on a surface of a semiconductor wafer, patterning a watermark sensitive structure on the first oxide layer, depositing a silicon layer over the first oxide layer, doping a region of the silicon layer over the watermark sensitive structure with an impurity to create a watermark sensitive region that is prone to retaining watermark formations as result of a wet processing step, and growing a second oxide layer over the silicon layer.
1. A method comprising:
growing a first oxide layer on a surface of a semiconductor wafer;
patterning a first watermark sensitive structure on the first oxide layer;
depositing a silicon layer over the first oxide layer;
doping a first region of the silicon layer over the first watermark sensitive structure with an impurity under a first condition to create a first watermark sensitive region that is prone, to a first degree, to retaining watermark formations as result of a wet processing step; and
growing a second oxide layer over the silicon layer.
2. The method of claim 1 , further comprising:
patterning a second watermark sensitive structure on the first oxide layer; and
doping a second region of the silicon layer over the second watermark sensitive structure with an impurity under a second condition to create a second watermark sensitive region that is prone, to a second degree, to retaining watermark formations as result of the wet processing step.
3. The method of claim 1 , further comprising:
subjecting the semiconductor wafer to the wet processing step;
enhancing a susceptibility to detection of at least one watermark formation created on at least one of the first and second watermark sensitive regions; and
detecting the at least one watermark formation.