Wafer Inspection System: Calibration and Measurement
Wafer surface scanners are widely used in semiconductor industries to detect particle contamination on wafers. The performance characteristics of a PMS SAS-3600 wafer surface scanner have been evaluated using ideal polystyrene latex (PSL). It was also used to measure irregularly shaped silicon particles. Three sizes of PSL spheres (0.199μm, 0.3μm, and 0.426μm) were used to study the sizing accuracy and counting efficiency of this wafer scanner. The results show that this scanner sizes 0.199μm and 0.3μm PSL reasonably accurate. But it cannot size 0.426μm PSL very well. The background noise lever was so high that this scanner could not measure particles near its nominal lower detection limit: 0.1μm. It over-counted Si particles by 28%. An electrostatic enhanced wafer deposition chamber was used to prepare the test wafers. Both the theoretical calculations and experimental results show that electrostatic force increases the deposition velocity by 2 orders of magnitudes for particles smaller than 1μm. The sedimentation is the dominant mechanism for particles larger than 1μm.
A new method of reducing the particle contamination in semiconductor manufacturing
In this paper, a new method of reducing particle contamination in semiconductor manufacturing is suggested. The factors of particle contamination are first listed by dividing the equipment into several blocks and several units. Then, these factors are investigated in order. In such a way, it becomes clear how the equipment generates the particles and where the particles move. Thus, we can take suitable measures to reduce particles.
Local and average heat transfer characteristics for a disk situated perpendicular to a uniform flow
Mesure en soufflerie du coefficient de transfert de chaleur moyen et de la repartition radiale du coefficient de transfert de chaleur pour un disque circulaire place dans un ecoulement normal uniforme pour des nombres de Reynolds allant de 5000 a 50000. Comparaison des valeurs experimentales du transfert de chaleur au point d'arret avec des previsions theoriques