10 is formed using commercially available cmos processing with a single polysilicon layer and two metal layers 1p2m since cmos processing is a well developed skill and technology the detailed process flow is not redundantly describe herein and the structure design and the material characteristic of the sensor 10 will be illustrated in the following first a heat isolation structure 101 is defined on the silicon substrate 100 wherein the heat isolation structure 101 is defined by utilizing the field oxide layer that is formed using local oxidation of silicon locos processing the portion surrounding the heat isolation structure 101 is defined as the thin oxide layer 101 a which is the gate oxide layer the thermocouple 102 is composed of a first thermocouple material 102 a and a second thermocouple material 102 b wherein the first thermocouple material 102 a comprises polysilicon material and the second thermocouple material is the first metal interconnection metal 1 which is for example of aluminum or aluminum alloy the first thermocouple material 102 a and the second thermocouple material 102 b are connected by the via hole metal 103 a which is for example tungsten w the sensor 10 also comprises an inter layer dielectric ild 103 an inter metal dielectric imd 104 and a passivation layer 106 furthermore in order to obtain the biggest temperature gradient temperature difference between the hot junction region 200 and the cold junction region 300 of the thermocouple 102 a heat pipe.