I want to use Al2O3 or HfO2 as the gate oxide material for GAA MOSFET in the SILVACO TCAD script . How can I do that?
Can I use them directly with just changing the dielectric constant value in the material portion written in my script or do I have to define it explicitly somewhere else?
Can someone tell me about this or share the script?
It will be a great help.
Dear Amit
Firstly you may have electronic specifications of the new material as Eg, ni, electric Permitivity , ... then Use the instruction .Material in Atlas as well as in some examples.
Here is a example , also there is other example in atlas package
go atlas
# Solar cell example number 7.
# This example is based on the reference:
#
# Korster, L.J.A., Smits, E.C.P., Mihailetchi, V.D., and Blom, P.W.M.
# "Device model for the operation of polymer/fullerene bulk heterojunction
# solar cell", Physical Review B, Vol. 72, (2005) pp. 085205-1, 085205-9.
#
# Here we specify a mesh of one square meter ( 1um x 1e12 um).
# Since the structure is essentially one dimensional we ignore
# variations if x and z.
#
mesh width=1e12
x.mesh l=0 s=1
x.mesh l=1 s=1
#
# In the Y direction we define a finer mesh to resolve variations due
# to the exponential variation of absorption and carrier distributions
# due to diffusion in opposite directions.
#
y.mesh l=0.00 s=0.001
y.mesh l=0.12 s=0.001
#
# For organic solar cells we define only a single organic region that
# represents a bulk heterojunction (BHJ) material.
#
region number=1 material=Organic
#
# Here we define the top and bottom electrodes which we define workfunctions
# in order to provice a build-in field for separation of electrons and holes.
#
electrode name=anode top
electrode name=cathode bottom
contact num=1 workf=1.0
contact num=2 workf=2.34
#
# We define the models. In this case we specify that we will solve for
# the singlet equation (singlet), accounting for Langevin recombination
# (langevin) and singlet exciton dissociation (s.dissoc).
#
model langevin singlet s.dissoc
#
# The parameter qe.exciton specifies the number of excitons generated for
# for each absorbed photon.
#
material qe.exciton=1.0
#
# This statement sets up some of the standard material parameters for the
# organic material (permittivity, affinity, band gap (difference between
# LUMO and HOMO) and densities of states.
#
material permi=3.4 affinity=1.0 eg300=1.34 nc300=2.5e19 nv300=2.5e19
#
# These statements set up parameters of the singlet exciton continuity
# equation in accordance with the reference.
#
material knrs.exciton=1.82694e6 lds.exciton=0.0 taus.exciton=1.0e20 rst.exciton=1.0
material a.singlet=1.32167 s.binding=0.28484
mobility mun0=2.5e-3 mup0=3.0e-4
#
# Here we use a C - interpreter function to define constant photogeneration
# rate throughout the device as suggested in the reference.
#
beam num=1 f.radiate=solarex07.lib
#
# This statement specifies that we want to examine the fundimental
# band parameters, conduction and valence band edges and electron
# and hole mobilities in the output structure files.
#
output band.par con.band val.band e.mob h.mob
#
# Parameters appearing on the method statement refer to numerical
# adjustments that are usually not required except to improve
# robustness or speed of solution.
# In this case we are specifying climit which controls the minimum
# resolvable carrier concentration and maxtrap which specifies the
# maximum number of cutbacks during any solve.
#
method climit=1e-4 maxtrap=0
#
# Next we obtain an initial static unbiassed solution
#
solve init
solve prev
#
# Here we turn on the optical source (sun). In this case the
# intensity has been calibrated to give the same results as were
# given in the reference.
#
solve b1=0.59
#
# Now we open a log file to capture the IV data.
# We then perform a voltage sweep to capture the IV characteristics
# of the device.
#
log outf=solarex07.log
solve vcathode=0 vstep=0.02 vfinal=.86 name=cathode
#
# Finally we plot the results.
#
tonyplot solarex07.log -set solarex07.set
#
quit
Amit Das HfO2 and Al2O3 are not a new material in SILVACO. You can use it like any other oxide like SiO2. But, if you want to change it properties you can do so. I have included an example.
region num=1 x.min=0.030 x.max=0.075 y.min=0 y.max=0.008 user.material=my_oxide
material material=my_oxide user.group=insulator user.default=oxide permittivity=24
You can also change other properties like bandgap, mobility, etc.
material material=name EG300=0.0 MUN=(mobility) MUP=(hole Mobility) affinity= user.group=S/C/I user.default=Si/Poly/SiO2
Khuraijam Nelson sir, can you please suggest something for this question?
"I want to work on the following topics with the following specifications :
Channel Length = 30 nm , R Channel = 10 nm , Doping of source/drain ~ 1016-1020 , Channel Doping ~ 1010 - 1016
1. I want to work on Gate All Around MOSFET
2. I want to work on Gate All Around MOSFET biosensor
Which models must be included in the ATLAS script in first and second part? Kindly suggest if someone have worked on it.
With different models, result comes out to be different and in different papers, a variety of model have been used. So, I am bit confused."
Amit Das Read the following article. Both of your questions are answered in the article.
Article Analytical modeling of gate-all-around junctionless transist...
Atlas library has these materials but if you want to define a new material you better to read Atlas manual. It's not hard at all.
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