The Chroma 7500 series are Sub-nanometer 3D Optical Profilers based on the Scanning White Light Interferometry. Through the sophisticated scanning system and the innovative algorithms, the surface profiles of the micro-structures are measured and analyzed.
The Chroma 7501 is a manual version optical profiler with four manual stages, flexible to modify for desired experiments. The Chroma 7502 is an automatic version optical profiler with five motorized stages and one manual stage to control the orientation of the sample and also to extend the vertical and lateral scanning ranges. All measurements are nondestructive, fast, and required no sample preparation. These two optical profilers are most applicable for R&D, production, process improvement and academic research units in the field.
The surface profiles of micro-structures are critical to the process control and quality control of advanced hi-tech industries in many areas; from semiconductors, flat panel display, optical communication, and MEMS, to biomedical and electronic packages, surface profiles determine the product's performance and function. The Chroma 7500 series also provide variety of the surface parameters such as step height, angle, area, volume, roughness, waviness, film thickness and flatness to satisfy the industrial and academic needs.
The Chroma 7500 series can resolve the height down to 0.1 nm, while the scanning range can be reached up to 4 mm in Chroma 7502. The series can also resolve submicron features in the lateral direction. Besides, The scanning areas of Chroma 7502 can be extended up 70*70 mm by using the computer controlled lateral scanning stages. Chroma 7500 Series Optical Profilers with the fast calibration procedures and algorithms, the system is calibrated against the NIST-traceable standards. Combining the advantages of innovative algorithm and roBust system integration, the measurement can be performed in high accuracy and with a wide scanning range.
Due to the diffraction of nearby points, the profile may be miscalculated the height in some position, it could cause the measured boundary contour to show wrong data by the known algorithms such as the Centroid method. Chroma 7500 Series Optical Profilers using the SNOP (Sub Nano Optical Profiler) software and Chroma's interference signal processing algorithms to analyze the white light interferogram. The boundary error problem is eliminated. Furthermore, The systems are also equipped with the Chroma's dark point correction function to isolate the data points which can not be evaluated by the white light interferometry. The function is working at the stage of data acquisition. The dark points can be eliminated efficiently. And, the dark points are modified according to the surrounding points to achieve roBust and reliable measurements.
The STA (Surface Texture Analysis) software provides comprehensive graphical software for the profile data analysis, modification and visualization. More than 150 line/surface profile parameters including roughness, waviness, flatness, summit, and valley .etc. are evaluated. High pass filter, low pass filter, fast Fourier transformation (FFT) , and peak- removing spatial filtering tools facilitate high/low/band pass filtering. The software also provides the polynomial fitting, region growing, whole surface, and multi-area surface leveling methods for the flexible leveling needs.
The Chroma 7502 system is equipped with automatic scanning stages. The best focal position can be automatically located by the motorized vertical scanning stage and a fast auto-focus algorithm. The orientation of the sample can be also leveled by the tilting stages and auto-leveling algorithm. The sample can be automatically tuned to the best focal and flat position in seconds and performed the measurement without tedious adjustment works.