Integrated thermopile sensor for automotive, spectroscopic and imaging applications, and methods of fabricating same

摘要

A highly integrated thermal sensor (10) is responsive to radiation having wavelengths within a predetermined band of wavelengths. The sensor, which may be a thermopile, is comprised of a substrate (16) comprised of at least one semiconductor material. The substrate includes at least one active region disposed within a first surface of the substrate. The sensor further includes a plurality of thermally- responsive junctions (HJ, CJ) between dissimilar materials (22, 24) that are disposed within the at least one active region, wherein at least one of the thermally- responsive junctions is a hot junction. The hot junction is thermally isolated from the substrate by being suspended from the substrate on dielectric bridges or, in another embodiment, by a thermally insulating and patterned polymer. In a backside illuminated embodiment of this invention the sensor further includes an optical cavity (26) formed within a second surface of the substrate in registration with the active region. The optical cavity includes a radiation absorbing region (28) that is thermally coupled to the at least one hot junction. The sensor further includes an optical filter (30) that is disposed over the optical cavity for admitting radiation within the predetermined band of wavelengths into the optical cavity for absorption by the radiation absorbing region.