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ELIMINATE COLUMNS X.MIN=0 X.MAX=4 Y.MIN=0.0 Y.MAX=3

removes every second vertical grid line within the rectangle bounded by x=0, x=4, y=0 and y=3 microns.

7.4.4. Specifying Regions and Materials

Once the mesh is specified, every part of it must be assigned a material type. This is done with REGION statements. For example:

REGION number =<integer><material_type><position parameters>

Region numbers must start at 1 and are increased for each subsequent region statement. You can have up to 200 different regions in ATLAS. A large number of materials is available. If a composition- dependent material type is defined, the x and y composition fractions can also be specified in the REGION statement.

The position parameters are specified in microns using the X.MIN, X.MAX, Y.MIN, and Y.MAX parameters. If the position parameters of a new statement overlap those of a previous REGION statement, the overlapped area is assigned as the material type of the new region. Make sure that materials are assigned to all mesh points in the structure. If this isn’t done, error messages will appear and ATLAS won’t run successfully.

You can use the MATERIAL statement to specify the material properties of the defined regions. But you must complete the entire mesh and doping definition before any MATERIAL statements can be used.

7.4.5. Specifying Electrodes

Once you have specified the regions and materials, define at least one electrode that contacts a semiconductor material. This is done with the ELECTRODE statement. For example:

ELECTRODE NAME=<electrode name><position_ parameters>

You can specify up to 50 electrodes. The position parameters are specified in microns using the X.MIN, X.MAX, Y.MIN, and Y.MAX parameters. Multiple electrode statements may have the same electrode name. Nodes that are associated with the same electrode name are treated as being electrically connected.

Some shortcuts can be used when defining the location of an electrode. If no y coordinate parameters are specified, the electrode is assumed to be located on the top of the structure. You also can use the RIGHT, LEFT, TOP, and BOTTOM parameters to define the location. For example:

ELECTRODE NAME=SOURCE LEFT LENGTH=0.5

specifies the source electrode starts at the top left corner of the structure and extends to the right for the distance LENGTH.

7.4.6. Specifying Doping

You can specify analytical doping distributions, or have ATLAS read in profiles that come from either process simulation or experiment. You specify the doping using the DOPING statement. For example:

DOPING<distribution_type><dopant_type><position_parameters>

Analytical Doping Profiles

Analytical doping profiles can have uniform or Gaussian forms. The parameters defining the analytical distribution are specified in the DOPING statement. Two examples are shown below with their combined effect shown in Figure 7.5.

DOPING UNIFORM CONCENTRATION=1E16 N.TYPE REGION=1

DOPING GAUSSIAN CONCENTRATION=1E18 CHARACTERISTIC=0.05 P.TYPE \ X.LEFT=0.0 X.RIGHT=1.0 PEAK=0.1

The first DOPING statement specifies a uniform n-type doping density of 10E16 cm-3 in the region that was previously labelled as region #1. The position parameters: X.MIN, X.MAX, Y.MIN, and Y.MAX can be used instead of a region number.

The second DOPING statement specifies a p-type Gaussian profile with a peak concentration of 10E18 cm-3. This statement specifies that the peak doping is located along a line from x = 0 to x = 1 microns. Perpendicular to the peak line, the doping drops off according to a Gaussian distribution with a standard deviation of 0.05 mm. At x<0 or x>1, the doping drops off laterally with a default standard deviation that is 70% of CHARACTERISTIC. This lateral roll-off can be altered with the RATIO.LATERAL parameter. If a Gaussian profile is being added to an area that was already defined with the opposite dopant type, you can use the JUNCTION parameter to specify the position of the junction depth instead of specifying the standard deviation using the CHARACTERISTIC parameter.

Figure 7.5. Parameters of the doping statement for Gaussian Doping Profiles.

7.4.7. Specifying Physical Models

Physical models are specified using the MODELS and IMPACT statements. Parameters for these models appear on many statements including: MODELS, IMPACT, MOBILITY, and MATERIAL. The physical models can be grouped into five classes: mobility, recombination, carrier statistics, impact ionization, and tunneling. Chapter 3: “Physics”, Section 3.6: “Physical Models” contains details for each model.

All models with the exception of impact ionization are specified on the MODELS statement. Impact ionization is specified on the IMPACT statement. For example, the statement:

MODELS CONMOB FLDMOB SRH FERMIDIRAC

IMPACT SELB

specifies that the standard concentration dependent mobility, parallel field mobility, Shockley-Read- Hall recombination with fixed carrier lifetimes, Fermi Dirac statistics and Selberherr impact ionization models should be used.

ATLAS also provides an easy method for selecting the correct models for various technologies. The MOS, BIP, PROGRAM, and ERASE parameters for the MODELS statement configure a basic set of mobility, recombination, carrier statistics, and tunneling models. The MOS and BIP parameters enable the models for MOSFET and bipolar devices, while PROGRAM and ERASE enable the models for programming and erasing programmable devices. For example, the statement:

MODELS MOS PRINT

enables the CVT, SRH, and FERMIDIRAC models, while the statement:

MODELS BIPOLAR PRINT

enables the CONMOB, FLDMOB, CONSRH, AUGER, and BGN.

Note: The PRINT parameter lists to the run time output the models and parameters, which will be used during the simulation. This allows you to verify models and material parameters. We highly recommend that you include the PRINT parameter in the MODEL statement.

Questions & Answers

find the 15th term of the geometric sequince whose first is 18 and last term of 387
Jerwin Reply
The given of f(x=x-2. then what is the value of this f(3) 5f(x+1)
virgelyn Reply
hmm well what is the answer
Abhi
how do they get the third part x = (32)5/4
kinnecy Reply
can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
ninjadapaul
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
ninjadapaul
I don't understand what the A with approx sign and the boxed x mean
ninjadapaul
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
ninjadapaul
oops. ignore that.
ninjadapaul
so you not have an equal sign anywhere in the original equation?
ninjadapaul
hmm
Abhi
is it a question of log
Abhi
🤔.
Abhi
Commplementary angles
Idrissa Reply
hello
Sherica
im all ears I need to learn
Sherica
right! what he said ⤴⤴⤴
Tamia
hii
Uday
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
Kevin Reply
a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
Kim
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Al
y=10×
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
how do you translate this in Algebraic Expressions
linda Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Solid state physics and devices-the harbinger of third wave of civilization. OpenStax CNX. Sep 15, 2014 Download for free at http://legacy.cnx.org/content/col11170/1.89
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