Assignment_3

# Assignment_3 - 4. For a photoresist that can resolve...

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Assignment 3 (Lithography). Due on June 23 before class. 1. An X-ray exposure system uses photons with an energy of 1keV. If the separation between the mask and wafer is 20 µ m, estimate the diffraction-limited resolution that is achieved by this system. (Answer: 0.15 µ m, or 0.24 µ m if taking the 3/2 factor, both are considered correct) 2. For EUV (extreme UV) projection lithography, wavelength is 13.5nm, what is the resolution if NA=0.3 according to Rayleigh criteria? (answer 27nm) 3. In the slide we calculated the depth of focus (DOF) for lithography in air (n=1). What is DOF for immersion lithography with refractive index n>1?
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Unformatted text preview: 4. For a photoresist that can resolve MTF=0.4, if the exposure system has NA=0.35, use g-line λ =436nm, spatial coherence S=0.5. What is the resolution? If using i-line (365nm) exposure, what is the resolution? (Answer: 1.46 µ m pitch or 0.73 µ m resolution/line-width/half pitch, 0.61 µ m resolution or 1.22 µ m pitch) 5. An exposure tool uses 248nm exposing wavelength with a spatial coherence of 0.5. It has a numerical aperture of 0.6. If this tool is used with a resist with a contrast of 3.5, calculate in microns the minimum line size that can be resolved. (Answer: 220nm half pitch) 2 2 ) ( NA n k λ...
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## This note was uploaded on 08/12/2010 for the course NE NE 343 taught by Professor Bo during the Spring '10 term at Waterloo.

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