MECFET-A Qualitative Analysis at nano level:
by: Deepalakshmi Chandrasekaran M.E., (VLSI)
E-Mail Id:
MECFET stands for metallic channel field effect transistor. The
channel is made of metallic conductor. This channel is implemented in FDSOI
NMOS structure replacing the semiconductor channel. There is no operations or
region of accumulation ,depletion and inversion. The surface of the metallic
channel is induced with electrons due to electrostatic action in MOM part of the
device.The desired characteristics is that the threshold voltage is very small such
that it almost reaches zero.It is known that NMOS passes logic 1(for eg:5V) with
degradation in voltage level(5-Vth),where Vth is the threshold voltage applied to the
gate.Beyond Vth only,the MOSFET conducts a considerable amount of
current.Qualitative analysis of the device is done based on sub-micron
technology,where the electron transport mechanism is quasi-ballistic in
nature.Landeaur approach is taken for analyzing the MECFET .
PROPOSED DESIGN
, The P-substrate is only for supporting the whole structure.The source and
drain are n-doped regions and the channel is made of metal.The metallic gate is
having the same length as the channel.The oxide layer is sandwitched between two
metallic layers(the gate on top and channel below).The MOM simplifies the
design like a classical capacitor.This statement is valid only if the oxide thickness
is above (4nm-5nm).Otherwise,the leakage current and quantum tunneling plays an
important role in characterizing the device.
In MECFET,the boundary conditions for junction between ,source-channel
and channel-drain junctions are ohmic.
Physics of the MOM region
Under VG=0,it is under equilibrium.
• Under positive bias applied to the gate,the Fermi level in the
channel gets shifted to higher energy level.[FIG:3]
by: Deepalakshmi Chandrasekaran M.E., (VLSI)
E-Mail Id:
MECFET stands for metallic channel field effect transistor. The
channel is made of metallic conductor. This channel is implemented in FDSOI
NMOS structure replacing the semiconductor channel. There is no operations or
region of accumulation ,depletion and inversion. The surface of the metallic
channel is induced with electrons due to electrostatic action in MOM part of the
device.The desired characteristics is that the threshold voltage is very small such
that it almost reaches zero.It is known that NMOS passes logic 1(for eg:5V) with
degradation in voltage level(5-Vth),where Vth is the threshold voltage applied to the
gate.Beyond Vth only,the MOSFET conducts a considerable amount of
current.Qualitative analysis of the device is done based on sub-micron
technology,where the electron transport mechanism is quasi-ballistic in
nature.Landeaur approach is taken for analyzing the MECFET .
PROPOSED DESIGN
, The P-substrate is only for supporting the whole structure.The source and
drain are n-doped regions and the channel is made of metal.The metallic gate is
having the same length as the channel.The oxide layer is sandwitched between two
metallic layers(the gate on top and channel below).The MOM simplifies the
design like a classical capacitor.This statement is valid only if the oxide thickness
is above (4nm-5nm).Otherwise,the leakage current and quantum tunneling plays an
important role in characterizing the device.
In MECFET,the boundary conditions for junction between ,source-channel
and channel-drain junctions are ohmic.
Physics of the MOM region
Under VG=0,it is under equilibrium.
• Under positive bias applied to the gate,the Fermi level in the
channel gets shifted to higher energy level.[FIG:3]
