V.E. Lashkaryov Institute of Semiconductor Physics NAS of Ukraine
National Academy of Sciences of Ukraine


128х128 and 4х288 multielement array photodetectors, based on CdHgTe epitaxial layers

№38 The Department for Physics and Technology of Low- Dimensional Systems
F.F. Sizov, Z.F. Tsybrii

06363 2

Silicon read-out circuit and fragment of 128х128 pixels CdHgTe focal plane array

Function. Focal plane array photodetector can be used for thermal image acquisition of different objects in real time for military and civil applications, particularly for medicine and municipal economy. Large-format photodetectors carry out such functions as eye’s retina, but in the invisible infrared spectral region.
Device description. The results of formation 128x128 and 4x288 multielement photodetector arrays, based on CdxHg1-xTe/ZnyCd1-yTe (x = 0.3; 0,2; y = 0.04) epitaxial layers grown by liquid phase epitaxy for the 3-5 and 8-12μm infrared spectral region were developed. Taking into account the specific mechanical and electro-physical properties CdHgTe material, the topology of photodetectors and also original elements of technology namely CdTe passivation films formation by hot wall epitaxy method, lift-off photolithography process, multilayer metallization peculiarities, and technology of indium contact fabrications have been elaborated.
The main technical and operating characteristics:                

Photodetector Working т-re, К Spectral region, mkm Pixel’s size, mкm2 The value of dark current U=-0,1В, нА Detectivity, D*, сm·Hz1/2·W-1
128х128 78  3-5 25х25 <10 ~1011
4х288 78 8-12 15х15 <10 ~1011