Patent ID: 6528789
Filing Date: 2003-03-04
Classification: G01J

Abstract:
A thermal infrared detector comprising:a substrate having a readout circuit; and a plurality of pixels patterned on said substrate at a pitch p in the range of 15&lE;p&lE;50 (&mgr;m) by an i-line stepper; each of said pixels having a photo-sensitive area including a thin film of bolometer and spaced from said substrate, two beams by which said photo-sensitive area is supported on said substrate, and interconnections formed respectively on said beams and connecting said readout circuit and said thin film of bolometer to each other; wherein each beam has a length determined by a beam length index n calculated by dividing the length of each of said beams by one-quarter of the peripheral length of said pixel; wherein a reference value n0 for the beam length index n is given by equations: n0=âˆ’1.8Ã—10âˆ’4p3+1.4Ã—10âˆ’2p2âˆ’0.27p+2.5 when said interconnections are made of a material having a thermal conductivity k in the range of 0.065&lE;k&lE;0.09 (W/(cmÂ·K));n0=âˆ’1.5Ã—10âˆ’4p3+1.3Ã—10âˆ’2p2âˆ’0.24p+2.3 when said interconnections are made of a material having a thermal conductivity k in the range of 0.10&lE;k&lE;0.15 (W/(cmÂ·K)); andn0=âˆ’1.1Ã—10âˆ’4p3+9.6Ã—10âˆ’3p2âˆ’0.17p+1.8 when said interconnections are made of a material having a thermal conductivity k in the range of 0.16&lE;k&lE;0.22 (W/(cmÂ·K));wherein said beam length index n is in the range of 0.85n0&lE;n&lE;1.15n0.