High‐performance backside‐illuminated Hg0.78Cd0.22Te/CdTe (λCO=10 μm) planar diodes

Planar infrared photodiodes have been fabricated on Hg1−xCdxTe (x=0.22) epitaxial layers which were grown on CdTe substrates by the liquid phase epitaxy technique. The n+‐p junctions were formed by ion implantation. The R0A products of the diodes have been measured to be ∼105 Ω cm2 at 40 K and ∼107 Ω cm2 at 20 K. These R0A values are believed to be the highest ever reported for HgCdTe photodiodes with comparable cutoff wavelengths. It was found that between 77 and 40 K the diode R0A was limited by generation‐recombination current. Effects of field plate bias on diode properties were also analyzed.