Device Level Electrothermal Analysis of Integrated Resistors

This paper presents the electrothermal simulation of integrated thin film resistors. Both the thermal and electrical problem is tackled by a semi-analytical method, without the need of generating an equivalent distributed network. As the electrical conductivity is temperature dependent, self-heating of the resistor will alterate the current distribution, leading to a non-uniform power dissipation. This then provokes a change of the temperature distribution, explaining the electrothermal coupling. Examples are given for various practical resistor designs. After a few iterations stable values for the electrical and thermal resistance and temperature and power distributions are obtained. The results show that even if one would anticipate the self-heating process based on an estimated average temperature, the behaviour will still deviate from the original design. This is caused entirely by the non-uniformity of the distributions inside the component.