suggest you to find some book of analog!
LVT SVT HVT,there are three corners.
LVT stand for the low Vth and HVT stand for hign. In physical design,MOSFET in LVT corner has low delay but it will cause high leakage.Inversely,HVT has hign delay and low leakage!
we should use LVT in critical path and use HVT in low power design!
BRS