Micro mirror arrays for improved sensitivity of thermopile infrared sensors

This paper reports an improved method for higher sensitivity of the thermopile infrared sensors .To increase the sensitivity of thermopile infrared sensors, the thermopile infrared sensors were bonded to the micro mirror arrays (MMA) which focused the infrared radiation in the infrared absorber. As the result, 4-pair thermopiles have demonstrated 220V/W to 350V/W under the pressure of 1Pa atmospheres, thus they are 1.6 times higher sensitivity than without MMA. The fabrication method of MMA is using etching depth difference of DRJE which depends on the aspect ratio with different size mask openings and isotropic RIE.