Methods exploiting a Self Aligned
Cell (SAC) architecture for
doping purposes, use the architecture to direct the deposition and application of either a
dopant or a
diffusion retarder.
Doping is provided in regions that will become metallization for conducting fingers.
Dopant may be treated directly into metallization grooves. Or,
diffusion retarder may be provided in non-groove locations, and
dopant may be provided over some or all of the entire
wafer surface.
Dopant and
metal automatically go where desired, and in register with each other. The SAC architecture also includes concave surfaces for light absorbing regions of a
cell, to reduce reflection of
light energy, which regions may also be treated with
dopant in the concavities, to result in
semiconductor emitter lines. Alternatively,
diffusion retarder may be treated into the concavities, leaving upper tips of ridges between the concavities exposed, thereby subject to deeper
doping.