Status of p-on-n HgCdTe technologies at DEFIR

This paper presents recent development made at CEA-LETI on manufacturing and characterization of planar p-on-n HgCdTe photodiodes on long-, mid- and short-wavelength. HgCdTe (MCT) layer was grown both by liquid-phase epitaxy (LPE) and by molecular beam epitaxy (MBE) on lattice matched CdZnTe (CZT). The n-type MCT base layer was obtained by indium doping. Planar p-on-n photodiodes were manufactured by arsenic doping, which has been activated by post-implanted annealing in Hg overpressure. As incorporation is achieved either by implantation or by incorporation (during MBE growth). Electro-optical characterizations on these p-on-n photodiodes were made on FPAs. Results show excellent operabilities (99.95% with ±0.5×mean value criterion) in responsivity and NETD and background limited photodetectors. For long-wavelength FPAs, dark current is very low, leading to a R0A product comparable to the state of the art at cut-off wavelength of λc = 9.2 μm. MBE mid-wavelength FPAs present very low responsivity dispersion, reaching 1.1%. Comparisons are made between implantation and growth incorporation As doping technologies.