Optical Surface profiler
Make: WYKO (Veeco Metrology Group) Model: Semi-custom Veeco large sample format Interferometric profiler. The operation is consistent with the NT3300 model. The OSP operates in two different modes. 1. Phase-shifting interferometry (PSI) mode which is used for very smooth surfaces with surface roughness less than 160 nm. The vertical resolution of the system is 0.1 nm in PSI mode 2. Vertical-scanning interferometry (VSI) which is suitable for rougher surfaces. The vertical resolution of the system is 1 nm in VSI mode for limited vertical scan range. This may be reduced for larger vertical scan ranges which go up to 1 mm with this instrument. The area imaged in a single scan, for a given objective magnification and field of view (FOV) setting, is tabulated below. Objective FOV Area (m m x mm) 50x 2 59 x 45 50x 1 120 x 91 50x 0.5 244 x 186 5x 2 591 x 449 5x 1 1200 x 910 5x 0.5 2400 x 1900 The lateral spatial resolution is 0.55 mm to 13.2 mm depending on the combination of objective magnification (5x or 50x) and Field of View (settings, 2, 1, or 0.5). The highest lateral resolution is obtained when the area imaged is the smallest. Larger areas can be imaged by stitching together multiple scans. The sample is moved on an x-y translation stage. 350 mm diameter wafers can be accommodated on the large sample stage.