Ballast Resistor Temperature Effect and Ruggedness

The temperature and self-heating behavior of multiple ballast resistor devices structure was examined with the observation that a silicided polysilicon resistor sitting on top of thick oxide has greater self-heating characteristics with little heat dissipated into the substrate. Conversely the same device structure sitting on top of thin oxide has less self-heating and improved heat dissipation to the substrate. Furthermore, the orientation of the device contacts relative to current flow also impacted device nominal resistance and ruggedness.