| 摘要 |
PURPOSE:To simplify constitution and to make instantaneous measurement possible, the forming an interferogram on an image sensor and calculating the distance between the main peak and the sub-peak thereof. CONSTITUTION:The continuous spectrum beam from a halogen lamp 16 is reflected from the surface of a silicon wafer 24 and the bottom surface of a trench 10 through a bifurcated optical fiber 38. A part of the incident luminous flux B0 from the fiber 38 penetrates through a beam splitter 40 to be reflected by flat mirror 42, 44 and, further, a part thereof penetrates through the spitter 40 to be incident on a Fourier transform lens 46 as luminous flux B1. A part of the luminous flux B0 is successively reflected by the aplitter 40, the flat mirrors 44, 42 and the splitter 40 be incident on the lens 46 as luminous flux B2. These luminous fluxes B1, B2 are processed by a signal process or52 through a unidimensional image sensor 48, and a main peak and a sub-peak are detected from the voltage signal of said device 52. Then, the distance between both of them is calculated and depth of a trench 10 is calculated on the basis of said distance.
|
