Threshold Adjust vs subthreshold leakage current ?

[nekoneko]

My problem is when i using threshold voltage adjust implantation i.e. boron implanted into the p-type substrate,
the observation vth is increases but the subthreshold leakage current also increases not decreases , why ?



Can help explain the clear concept...
Thanks

 

[dick_freebird]

The implant damages the silicon and may be gettered into
the oxide, adding to surface states which drag out the
subthreshold slope. You might dig into whether the leakage
is channel or junction in your particular case. A higher body
doping also increases the D-B field at the drain.