Doped structures for improved ingaas performance in imaging devices

摘要

In a semiconductor p-i-n photodiode an undoped absorption region (10) is epitaxially grown between two highly doped regions (14, 16). In prior art lattice matched InGaAs p-i-n photodiodes current epitaxial structures use low InP cap (16) doping (n~2.5-6x1016/cm3), and nominally undoped (not intentionally doped, n~1x1013-5x1014/cm3) InGaAs absorption regions (10). The shunt resistances of p-i-n photodiodes according to the present invention with intentional doping between n~5x1017/cm3 and 1x1014/cm3, in the InGaAs absorption region (52, 60) are significantly increased over that of a standard structure (non-intentionally doped).