Method and apparatus for detecting backside contamination during fabrication of a semiconductor wafer
View Patent ↗A method of detecting contamination on a backside of a semiconductor wafer includes the steps of positioning the backside of the wafer in contact with a detection surface of a contaminant sensor, and detecting deformation of the detection surface of the contaminant sensor. The contaminant sensor may be incorporated into a fabrication device such as a wafer handling device, or can be utilized in the construction of a stand-alone device. An apparatus for detecting contamination on the backside of a semiconductor wafer is also disclosed.
1. An apparatus for fabricating a semiconductor wafer, comprising:
a wafer handling device, and
a contaminant sensor secured to the wafer handling device, the contaminant sensor being configured to detect presence of a contaminant on a backside of the wafer when the wafer is positioned in the wafer handling device, wherein the contaminant sensor comprises a deformable detection surface configured to contact the backside of the wafer when the wafer is positioned in the wafer handling device.
2. The apparatus of claim 1 , wherein:
the contaminant sensor is configured to output (i) a first control signal indicative of a first capacitance value when the backside of the wafer is devoid of contaminant particles, and (ii) produce a second control signal indicative of a second capacitance value when a contaminant particle is present on the backside of the wafer, and
the first control signal is different from the second control signal.
3. The apparatus of claim 1 , wherein the contaminant sensor comprises a first conductive film, a second conductive film, and a dielectric film positioned between the first conductive film and the second conductive film.
4. The apparatus of claim 3 , wherein the first conductive film is configured to contact the backside of the wafer when the wafer is positioned in the wafer handling device.
5. The apparatus of claim 1 , wherein the contaminant sensor comprises a pressure sensing film.
6. The apparatus of claim 1 , wherein the contaminant sensor comprises a liquid crystal film.