A study of wafer charging with CHARM and SPIDER monitors

Wafer charging effects in an Applied Materials 9500 implanter were studied for high current As and BF2 implants with EEPROM-based sense and measurement devices (CHARM(R)-2) and transistor structures (SPIDER). The operational modes of the implanter were deliberately driven non-optimal states in order 60 test the sensitivity of the wafer-level monitors. Good correlation was found between data from the CHARM and SPIDER monitors as well as from machine-based indicators, such as the wheel current. A broad and stable operating window was seen for operation under normal conditions.