|
Freescale looks both ways |
|
|
|
Dec 05, 2005 at 05:30 PM |
|
By Dr Mike Cooke
Freescale Semiconductor believes that a combination of
vertical and planar thin body structures within a single transistor overcomes
many of the design and manufacturing challenges associated with vertical multi-gate
devices. The invention is called an Inverted T Channel-Field Effect Transistor
(ITFET) device.
Traditional CMOS devices deploy transistors onto the surface
of the silicon in a planar -- or horizontal -- fashion. Some proposed new
device architectures use vertical transistors to reduce leakage and provide
higher drive currents, among other properties, through having more than one
gate to control the device (e.g. FinFETs). Multiple gates pack more computing
power into less space and reduce power consumption. But vertical transistors
present fundamental design and manufacturing challenges related to mechanically
stability, sub-lithographic feature sizes and patterning over-tall
topographies.
Freescale's new device attempts to combine the stability and
manufacturability of planar devices with the low leakage and other benefits of
vertical devices. The company says that ITFETs offer better manufacturability
than FinFET transistors and other vertical devices, along with lower current
leakage, easier transistor width proportioning, lower parasitic capacitance and
increased on-current compared with pure planar devices. The device's vertical
and planar regions couple to enhance current capability from an increased
channel width without increasing the chip area. The ITFET incorporates silicon
in the planar regions below the vertical channels, thereby improving
manufacturability by reducing undercut below the vertical channels, lowering
parasitic resistance and enhancing the mechanical stability of the vertical channels.
The ITFET device was fabricated using on 90nm CMOS
silicon-on-insulator production equipment at Freescale's Austin Technology
& Manufacturing Center. Freescale plans to incorporate ITFET technology in
a range of high-end devices beginning at the 45nm node and beyond.
The company is presenting demonstration results for its
ITFET at this week's International Electron Devices Meeting (IEDM) in
Washington, DC.
|
News 
