SOI MOSFET
Encyclopedia
In electronics
Electronics
Electronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...

, an SOI MOSFET semiconductor
Semiconductor
A semiconductor is a material with electrical conductivity due to electron flow intermediate in magnitude between that of a conductor and an insulator. This means a conductivity roughly in the range of 103 to 10−8 siemens per centimeter...

 device is a Silicon on Insulator
Silicon on insulator
Silicon on insulator technology refers to the use of a layered silicon-insulator-silicon substrate in place of conventional silicon substrates in semiconductor manufacturing, especially microelectronics, to reduce parasitic device capacitance and thereby improving performance...

 (SOI) MOSFET
MOSFET
The metal–oxide–semiconductor field-effect transistor is a transistor used for amplifying or switching electronic signals. The basic principle of this kind of transistor was first patented by Julius Edgar Lilienfeld in 1925...

 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 advantage 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.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK