Accurate High Temperature Measurements Using Local Polysilicon Heater Structures

Conventionally, measurements of temperature-dependent device parameters and degradation are performed using thermo chucks or dedicated test-furnaces. With such an equipment, the available temperature range is limited (typically to a maximum of 300 ^°C) and reliable temperature switches are rather slow, i.e., in the range of minutes to hours. We refine the recently suggested use of polycrystalline silicon wires, so-called poly-heaters, embedded directly on the chip next to a semiconductor device under test, allowing for fast, accurate, and reliable local temperature control. Based on our previous experience with such structures, we extend the use of the poly-heater to even higher temperatures using a simple methodology. For this, we determine the temperature of the device by the electrical power dissipated in the heater wires, where we take the temperature dependency of the thermal resistances of the materials surrounding the heater and the device into account. With this approach, we obtain convincing agreement for comparisons with experimental data and three-dimensional electrothermal FEM simulations.