Estimating IC self-heating for on-wafer measurements

On-wafer measurement of single chips can be critical in terms of self-heating. This study discusses and analyzes typical configurations when measuring single unpackaged chips. Calculations and measurements demonstrate that already for power levels below 100mW the die temperature can exceed 100 °C, which may cause malfunction of the circuit or even damage the equipment. Infrared images show typical temperature profiles on a chip for different measurement setups. Methods are proposed how the chip temperature can easily be estimated, and it is shown that the thermal resistance can effectively lowered by suitable choice of the carrier material.