CMOS micro-heater design for direct integration of carbon nanotubes

Carbon nanotubes (CNTs) are nanomaterials that exhibit many remarkable electrical, mechanical and thermal properties, which can be exploited in various smart sensing applications by integrating them in standard CMOS processes. However, such integration technique is challenging since CMOS does not tolerate high temperatures required for local CNT synthesis. This work involves designing power efficient CMOS micro-heaters that can generate CNT growth temperature (~ 900 °C) in a post-CMOS CNT fabrication step, while maintaining CMOS compatible temperature (< 300 °C) in the microsystem. One suitable metal interconnect layer and a polysilicon layer available in AMS 0.18 μm CMOS technology have been used to design and simulate the micro-heaters. This paper proposes and compares six different optimal micro-heater designs alongside their thermal and thermomechanical analysis using multiphysics simulation software, ANSYS. Feasibility of implementing the designed micro-heaters in a real chip is discussed based on the analysis. Required CMOS post processing steps for the designed micro-heaters are also discussed. The promising results are expected to lead the way for successful implementation of carbon nanotube based sensors in a commercial CMOS process.