Warpage Measurement on Dielectric Rough Surfaces of Microelectronics Devices by Far Infrared Fizeau Interferometry1

Far infrared Fizeau interferometry is developed and it is proposed as a tool for warpage measurement of microelectronics devices. The method provides a whole-field map of surface topography with a basic measurement sensitivity of 5.31 μm per fringe contour. The method is implemented by a compact apparatus using a computer controlled environmental chamber for real-time measurement. The method retains the simplicity of classical interferometry while providing wide applicability to dielectric rough surfaces. Roughness tolerance is achieved by utilizing a far infrared light (λ=10.6 μm). The detailed optical and mechanical configuration is described and selected applications are presented to demonstrate the applicability. The unique advantages of the method are discussed. [S1043-7398(00)01303-7]