A highly reflecting back illuminated diode structure allows light that has not
been absorbed by a semiconductor absorbing region to be back reflected for at least
a second pass into the absorbing region. The diode structure in a preferred embodiment
provides a highly reflecting layer of gold to be supported in part by a conducting
alloyed electrode ring contact and in part by a passivation layer of SixNy.
Conveniently this structure provides a window within the contact which allows light
to pass between the absorbing region and the reflecting layer of gold.
