Q1 :
WHy 0.13um leakage current is large then 0.18um ?
How leakage happened? that's means drain or source to bulk, gate can not lead leakage, so oxide thickness can not determine the leakage number. .13 process have less design rule, that's means the isolation layer and space is smaller than 0.18 process, if the isolation is not working well, then leakage is more large. The other hand, .13 and .18 process have difference doping depth, that's means the pn junction is difference, and with the larger area of active area, so the leakage is more large.