Lithography Flashcards
1
Q
What is CAD (in lithography)?
A
Computer Automated Design
2
Q
What is registration in terms of a photomask?
A
The overlay accuracy from layer to layer
3
Q
What should be taken into account when the feature size is comparable to the optical wavelength?
A
Diffraction and interference
4
Q
What is the Fraunhofer (farfield) criterion?
A
W^2 «_space;lambda*sqrt(g^2+r^2)
W = mask width
g = distance between mask and wafer
r = distance from wafer center to observation point
5
Q
What is the modulated transfer function (MTF)?
A
(I_max - I_min)/(I_max + I_min)
6
Q
What does a high MTF (modulated transfer function) mean?
A
High contrast
7
Q
How can the wavelength be selected in an optical system?
A
By a series of higpass- and lowpass filters
