May I know what is wrong with the program as it is not showing any output?

This program is regarding variation of threshold voltage with lateral straggle, and am just geting a empty graph. Please help me as i am having my 1st PROJECT REVIEW

[Wayne King]

How are we supposed to answer this question?

[ARTI]

please find the program in attachments

[Walter Roberson]

The attachment did not make it.

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/7924-where-can-i-upload-images-and-files-for-use-on-matlab-answers

[ARTI]

if true
  % code
Nde=2.7*10^19;
Nsdp=1*10^20;
lateralstraggle=2*10^-9;
seff=log(Nde/Nsdp)*(-2*(lateralstraggle)^2)
Lg=70*10^-9;
Leff=Lg-(2*seff)
Deff=seff+Leff
k=1;
T=20;
q=1.6*10^-19;
Vt=(k*T)/q
ni=1;
Eg=1.17*1.6*10^-19;
nieff=(ni^2*exp(Eg/k*T))^1/2
Nde=2.7*10^19;
Na=56;
Vbi=Vt*log(Nde*Na/(nieff)^2)
epsilon=32;
epsilonox=4;
tsi=20*10^-9;
tox=1.2*10^-9;
lambda=(epsilon*tsi*tox)/(2*epsilonox)
vgs=2;
vfb=1;
q=1.6*10^-19;
Na=56;
Nsdp= 1*10^20;
x=4.6*(1.6*10^-19);
lateralstraggle=7;
Nsdx=Nsdp*exp((-x^2)/(2*lateralstraggle^2))
Lg=4;
Sd=4;
Nde=2.7*10^19;
Ei0=0.054*(1.6*10^-19);
Ei=Ei0*(1-(Nsdx/Nde)^1/3)
Eg=34;
eg=24;
Egeff=Eg-eg
Ed= Egeff-Ei;
Ef=8;
Eg=3;
ni=8;
nieff=(ni^2*exp(Eg/k*T))^1/2
Nsdx=Nsdp*exp((-x^2)/(2*lateralstraggle^2))+Nsdp*exp((-(Lg-x)/2*lateralstraggle^2))/(1+Sd*exp((Ef-Ed)/k*T))
PI=(vgs-vfb)-lambda^2*q*(Na-Nsdx)/epsilon
Vds=1.3607e+003;
c2=((Vbi-PI)*(1-(exp(-Deff/lambda))/(exp(-seff/lambda))+Vds))/(exp(Deff/lambda))-(exp(seff/lambda))/(exp(-seff/lambda))*(exp(-Deff/lambda))
c1=(Vbi-c2*exp(seff/lambda)/exp(-seff/lambda))*exp(-Deff/lambda)
si=c1*exp(-x/lambda)+c2*exp(x/lambda)+PI
Ni=2;
fi=Vbi*log(Na/Ni)
Na=3;
Vth=vfb+(2*fi)-(c1*exp(-x/lambda))-(c2*exp(x/lambda))+(lambda^2)*q*(Na-Nsdx)/epsilon
plot(lateralstraggle,Vth)
ylabel('Vth, V')
xlabel('lateralstraggle,nm')

end

Answer 1

[Walter Roberson]

Your plot is not empty: you just cannot pick out the data it plots. You can emphasize the data by changing the color and marker:

plot(lateralstraggle,Vth, 'ro-')

[ARTI]

sir am still not getting it.Please help as i dont know what is the color and marker?

[Walter Roberson]

Red circle. You should see exactly one of them, in roughly the middle of the plot. You only have one point to plot.

[Image Analyst]

Or try it like this to make it super obvious:

plot(lateralstraggle,Vth, 'r*', 'MarkerSize', 15, 'LineWidth', 3)

[ARTI]

Actually sir it's like lateral straggle varying from 2nm to 5nm. and this i don't know how to write in the matlab. will you please tell me how to do it and i need to get a graph like fig 3 as per the base paper which i am attaching with it.

[Walter Roberson]

Your current code has lateralstraggle=2*10^-9 so should we assume that the unit is meters, and thus that 5 nm would correspond to 5*10^(-9) ? What increment are you hoping for? Why, later in the code, do you set lateralstraggle=7 (i.e., 7 meters) ?

[Walter Roberson]

Please re-check your Nsdx . As one subexpression of it you have

exp((-(Lg-x)/2*lateralstraggle^2)

but everywhere else that the subexpression 2*lateralstraggle^2 appears, it is always bracketed into a single unit, (2*lateralstraggle^2) . Are you sure that everywhere else you want to be dividing by the whole product, but in that one sub-expression you want to be dividing by only 2, and multiplying the result by latteralstraggle^2 ?