Atomic force microscopy (AFM) statistical process control for microelectronics applications

The microroughness of silicon surfaces has been shown to affect photolithographic processes, gate oxides, and wafer bonding. Atomic force microscopy (AFM) is an indispensable tool for monitoring surface microroughness. However, the long-term reliability of this measurement technique must be established before it can be routinely applied in the microelectronics industry. We investigated several important characteristics that must be well controlled for consistent microroughness measurements: tip quality, piezo tube calibration, and choice of the proper statistical process control (SPC) sample. © 1995.