Development of selenium-doped silicon for 3–5 μm applications

Abstract

The diffusion coefficient, solubility and energy levels of selenium in silicon have been determined, and two types of selenium-doped silicon infrared detectors have been fabricated and tested. A longer-wavelength-response material, containing deliberate additions of acceptor dopants, operates at temperatures below 77 K and has a spectral-response half-power point at 6.2-μm. This 6.2-μm response is believed to be due to the association of selenium with acceptor dopants. Si:Se detectors made from materials having no deliberate additions of acceptor dopants have been operated at temperatures greater than 90 K, and exhibit a spectral-response half-power point at 4.1 μm. Peak D ∗ λ (λ = 3.8 μm) values as high as 1.5 × 10 11 cm Hz 1 2 /W have been measured in devices of this latter type.