Low temperature processed back side redistribution lines (RDLs) are
disclosed. Low temperature processed back side RDLs may be electrically
connected to the active surface devices of a semiconductor substrate
using through wafer interconnects (TWIs). The TWIs may be formed prior to
forming the RDLs, after forming the RDLs, or substantially simultaneously
to forming the RDLs. The material for the back side RDLs and various
other associated materials, such as dielectrics and conductive via filler
materials, are processed at temperatures sufficiently low so as to not
damage the semiconductor devices or associated components contained on
the active surface of the semiconductor substrate. The low temperature
processed back side RDLs of the present invention may be employed with
optically interactive semiconductor devices and semiconductor memory
devices, among many others. Semiconductor devices employing the RDLs of
the present invention may be stacked and electrically connected
theretogether.