Patent ID: 9360302
Filing Date: 2016-06-07
CPC Classification: G01B

Claim Text:
1. A sensor apparatus, comprising: a substrate; a material layer over the substrate, wherein the material layer has a top surface and a bottom surface; one or more units located between the material layer and the substrate at one or more spatially separated locations, wherein each unit includes at least one light source and at least one corresponding photodetector, wherein the at least one light source is configured to emit or channel light towards the material layer, wherein the at least one light source and at least one corresponding photodetector are configured so that the at least one photodetector detects optical output from the at least one light from the light source interacting with at least the top and bottom surfaces of the material layer for measuring a thickness, a change of thickness or a rate of change of the thickness of the material layer, wherein for each unit both the at least one light source and the at least one photodetector are formed from the substrate, and wherein the sensor apparatus has a thickness similar to that of a standard semiconductor wafer.