Patent ID: 7424389
Filing Date: 2008-09-09
Classification: G01B,H01L

Abstract:
1. A method of calculating the thickness or the rate of change of thickness of a layer having at least one component capable of light emission when illuminated by light as the layer is being formed on a substrate, comprising: a) illuminating the layer through the substrate with light that transmits through the layer and causes the light emission component to emit light by transporting an excitation fiber and wherein the emitted light is collected by a collection fiber with the excitation fiber and the collection fiber forming an angle of 20-25 degrees; b) collecting a portion of the light emission from the component of the layer through the substrate; c) calculating the layer thickness or the rate of change of layer thickness based on the intensity of the light emission from the component of the layer; and d) storing or displaying the resultant thickness or rate of change of thickness of the layer.