Infrared detector having active regions and isolating regions formed of CdHgTe

In a method for fabricating an infrared detector, initially, a CdHgTe layer of a first conductivity type is produced on a front surface of a semiconductor substrate, a plurality of spaced apart CdHgTe regions of a second conductivity type, opposite the first conductivity type, are produced at the surface of the first conductivity type CdHgTe layer, and part of the surface of the first conductivity type CdHgTe layer between the second conductivity type CdHgTe regions is selectively irradiated with a charged particle beam to evaporate Hg atoms from that part, whereby a CdHgTe separation region of the first conductivity type and having a Cd composition larger than that of the first conductivity type CdHgTe layer is produced penetrating through the first conductivity type CdHgTe layer and surrounding each of the second conductivity type CdHgTe regions. Therefore, a highly-integrated high-resolution infrared detector with no crosstalk between pixels is achieved.