Full wafer thickness map reflectometry

A thickness measuring system comprising:

• a camera positioned above a center of a semiconductor structure to capture light reflected by the semiconductor structure, the semiconductor structure comprising a silicon on insulator (SOI) structure including at least an SOI layer and a buried oxide (BOX) layer;
• at least one light source providing incoherent, uncollimated light;
• and
• a controller including a processor and a memory, the controller operatively coupled to the camera and the at least one light source, the memory including instructions that when executed by the processor cause the controller to:
• illuminate the semiconductor structure with the incoherent, uncollimated light from the at least one light source;
• cause the camera to capture a plurality of images of the semiconductor structure illuminated by the light from the light source, the plurality of images including separate first color, second color, and third color images, the first, second, and third colors being different from each other;
• and
• produce thickness maps for at least two layers of the semiconductor structure based on the first color, second color, and third color images and reference first color, second color, and third color images of a reference silicon wafer, including calculating an average thickness of each layer and calculating final thickness maps for each layer as first order deviation maps from the average thickness of that layer using
• (
• SOI
• BOX
• )
• =
• (
• Δ
• ⁢
• SOI
• Δ
• ⁢
• BOX
• )
• +
• (
• SOI
• _
• BOX
• _
• )
• .