Direct integration of Carbon Nanotubes (CNTs) in CMOS is important for commercially manufacturing low-cost CNT-based sensors. In such compact sensors, CNTs would act as sensing element, and CMOS circuits would process relevant signals from the CNTs. CNTs can be directly synthesized and integrated into CMOS by local thermal chemical vapor deposition (CVD), where a hot spot of 900 °C can be generated by CMOS micro-heaters. However, a sufficient thermal gradient between the micro-heaters and nearest CMOS devices is a prerequisite to ensure non-destructive temperature (<300 °C) in the electronic circuit regions. Our previous works have shown modelling and simulation of various CMOS micro-heaters that are promising for fulfilling these temperature requirements. In this paper, we investigate the layout designs of different metal and polysilicon micro-heaters using AMS 0.35μm CMOS process. Optical micrographs of the fabricated micro-heaters are also presented.