Fabrication and characterization of CMOS-MEMS thermoelectric micro generators.
This work presents a thermoelectric micro generator fabricated by the commercial 0.35 μm complementary metal oxide semiconductor (CMOS) process and the post-CMOS process. The micro generator is composed of 24 thermocouples in series. Each thermocouple is constructed by p-type and n-type polysilicon strips. The output power of the generator depends on the temperature difference between the hot and cold parts in the thermocouples. In order to prevent heat-receiving in the cold part in the thermocouples, the cold part is covered with a silicon dioxide layer with low thermal conductivity to insulate the heat source. The hot part of the thermocouples is suspended and connected to an aluminum plate, to increases the heat-receiving area in the hot part. The generator requires a post-CMOS process to release the suspended structures. The post-CMOS process uses an anisotropic dry etching to remove the oxide sacrificial layer and an isotropic dry etching to etch the silicon substrate. Experimental results show that the micro generator has an output voltage of 67 μV at the temperature difference of 1 K.
Department of Mechanical Engineering, National Chung Hsing University, Taichung, 402, Taiwan. d9461402@mail.nchu.edu.tw
Pin-Hsu
PH
Kao
Po-Jen
PJ
Shih
Ching-Liang
CL
Dai
Mao-Chen
MC
Liu
D008670:Metals / Q000737:chemistry; D055617:Micro-Electrical-Mechanical Systems; D010087:Oxides / Q000737:chemistry; D012666:Semiconductors; D012825:Silicon / Q000737:chemistry; D013696:Temperature
D008670:Metals; D010087:Oxides; D012825:Silicon