Patent ID: 8835906

Claim:
A sensor comprising: a base wafer containing silicon; a seed member provided directly or indirectly on the base wafer: a photothermal absorber that is made of a Group 3-5 compound semiconductor lattice-matching or pseudo lattice-matching the seed member and being capable of generating a carrier upon absorbing light or heat; and a recombination repressor that is formed in contact with a side wall of the photothermal absorber and represses recombination of a currier generated by the Group 3-5 compound semiconductor on the side wall, the recombination repressor having a semiconductor or a dielectric having a larger band gap than the band gap of the photothermal absorber; wherein the photothermal absorber outputs an electric signal in response to incident light to be introduced into the photothermal absorber or heal to be applied to the photothermal absorber, the photothermal absorber is a superlattice structure in which a first layer and a second layer are stacked together, the first layer is made of Ga x1 In 1-x1 N y1 P z1 As w1 Sb 1-y1-z1-w1 (0≦x1≦1, 0≦y1≦1, 0≦z1≦1, 0≦w1≦1, and 0≦y1+z1+w1≦1) and the second layer is made of Ga x4 In x4 In 1-x4 N y4 P z4 As w3 Sb 1-y4-z4-w3 (0≦x4≦1, 0≦y4≦1, 0≦z4≦1, 0≦w3≦1, and 0≦y4+z4+w3≦1) and has a band gap larger than the band gap of the first layer, the seed member is made of C x2 Si y2 Ge z2 Sn 1-x2-y2-z2 (0≦x2<1, 0≦y2≦1, 0≦z2≦1, and 0<x2+y2+z2≦1), and the sensor further comprises an interface region formed inside the base wafer in contact with an interface between the base wafer and the seed member, the interface region having a composition C x2 Si y2 Ge z2 Sn 1-x2-y2-z2 (0<x2≦1, 0<y2′≦1, 0≦z2≦1, 0<x2+y2+z2≦1, and y2<y2′<1).