dear all:
     When i design my vco, i come across a problem about varactor. My process is tsmc .18 and I want a small varactor ,but i find that the minimum finger of varactor is 10,  if the hard_constrain is unchecked, the finger can be changed smaller. but i cant find any illustration about the option "hard_constrain"

I don't know how to deal with it.

help me. THKS!