@User what did you exactly mean by the second case a flip well (LVt) and top is RVt ?

@promach I meant that in STMicro we used to call that a flip well. But please do not quote me on this as it has been a few years back.

@mehdi you mean flipped-well (FBB mode) is LVt , conventional-well (RBB mode) is RVt ?

@promach Correct. You can take a look at: https://islped.org/2014/files/ISLPED2014_FD_SOI_Philippe_Flatresse_STMicroelectronics.pdf