In electronics, an SOI MOSFET semiconductor device is a silicon on insulator (SOI) MOSFET structure in which a semiconductor layer, e.g. silicon, germanium or the like, is formed above an insulator layer which may be a buried oxide (BOX) layer formed in a semiconductor substrate. SOI MOSFET devices are adapted for use by the computer industry. The buried oxide layer can be used in SRAM memory designs. There are two type of SOI devices: PDSOI (partially depleted SOI) and FDSOI (fully depleted SOI) MOSFETs. For a n-type PDSOI MOSFET the sandwiched p-type film between the gate oxide (GOX) and buried oxide (BOX) is large, so the depletion region can't cover the whole p region. So to some extent PDSOI behaves like bulk MOSFET. Obviously there are some advantages over the bulk MOSFETs. The film is very thin in FDSOI devices so that the depletion region covers the whole film. In FDSOI the front gate (GOX) supports less depletion charges than the bulk so an increase in inversion charges occurs resulting in higher switching speeds. Other drawbacks in bulk MOSFETs, like threshold voltage roll off, higher sub-threshold slop body effect, etc. are reduced in FDSOI since the source and drain electric fields can't interfere due to the BOX. The main problem in PDSOI is the "floating body effect (FBE)" since the film is not connected to any of the supplies.