Browse Prior Art Database

Silicon Wafer Surface Inspection Device

IP.com Disclosure Number: IPCOM000073939D
Original Publication Date: 1971-Feb-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

O'Hora, DE: AUTHOR

Abstract

This device is for the detection of epitaxial spikes and other protrusions on a semiconductor wafer and also for the detection of pinholes in photoresist. The device utilizes the selective transmission of infrared light through the silicon wafer in areas not covered by a polymeric coating.

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Silicon Wafer Surface Inspection Device

This device is for the detection of epitaxial spikes and other protrusions on a semiconductor wafer and also for the detection of pinholes in photoresist. The device utilizes the selective transmission of infrared light through the silicon wafer in areas not covered by a polymeric coating.

The device includes a source 10 of infrared light, an infrared detector and converter 12 positioned to receive light from the infrared source 10, and an image display device 14, such as a television monitor, connected to the detector and converter 12 by cable 16 to receive an output from the detector and converter.

For the detection of epitaxial spikes and other protrusions on a silicon semiconductor wafer 18, a polymeric coating 20 nontransparent to infrared light is applied to the surface of the wafer 18 on which protrusions 22 are to be detected in a thickness corresponding to the minimum protrusion height to be detected by the apparatus. Such a coating may be applied by spinning techniques utilized for the application of photoresist to silicon wafers. The wafer 18 and protrusions 22 on its surface are transparent to infrared light 24. Where protrusions do not exist on the wafer surface, transmission of the infrared light 24 is blocked by the nontransparent polymeric coating 20. Where the protrusions 22 extend above the polymeric coating 20, infrared light 24 is passed through the wafer 18 to infrared detector and converter 12. Protrus...