ATOMIC-FORCE MICROSCOPY (AFM) STATISTICAL PROCESS-CONTROL FOR MICROELECTRONICS APPLICATIONS

The microroughness of silicon surfaces has been shown to affect photol ithographic processes, gate oxides, and wafer bonding. Atomic force mi croscopy (AFM) is an indispensable tool for monitoring surface microro ughness. However, the long-term reliability of this measurement techni que must be established before it can be routinely applied in the micr oelectronics industry. We investigated several important characteristi cs that must be well controlled for consistent microroughness measurem ents: tip quality, piezo tube calibration, and choice of the proper st atistical process control (SPC) sample.