Specific Process Knowledge/Lithography/Aligners/Aligner: Maskless 01 processing: Difference between revisions
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Please see the section [[Specific_Process_Knowledge/Lithography/Aligners/Aligner:_Maskless_01_processing#Optimal_use_of_the_maskless_aligner|further down]]. | Please see the section [[Specific_Process_Knowledge/Lithography/Aligners/Aligner:_Maskless_01_processing#Optimal_use_of_the_maskless_aligner|further down]]. | ||
==Resolution | ==Resolution== | ||
The pixel-size of the DMD in the ligner: Maskless 01 is 0.5µmX0.5µm (at the sample surface). The lithographic resolution of the machine is 1µm on paper, which was demonstrated in the acceptance test after installation using a resist thickness of 0.5µm. This result has later been confirmed. In 1.5µm thick resist, the resolution is around 2µm. | The pixel-size of the DMD in the ligner: Maskless 01 is 0.5µmX0.5µm (at the sample surface). The lithographic resolution of the machine is 1µm on paper, which was demonstrated in the acceptance test after installation using a resist thickness of 0.5µm. This result has later been confirmed. In 1.5µm thick resist, the resolution is around 2µm. | ||
The table below shows the result of a resolution test using 1.5µm and 0.5µm positive resist. For 1.5µm resist the resolution is 2µm, maybe even a little lower, while it is 1µm, or at least close to, for 0.5µm resist. The optimal dose depends on the designed structures; dots require a lower dose in order to print to size than lines. | The table below shows the result of a resolution test using 1.5µm and 0.5µm positive resist. For 1.5µm resist the resolution is 2µm, maybe even a little lower, while it is 1µm, or at least close to, for 0.5µm resist. The optimal dose depends on the designed structures; dots require a lower dose in order to print to size than lines. In the case of a dark field design, trenches would probably require a lower dose in order to print to size than lines, while holes would require a higher dose to print than trenches. | ||
Also evident in the pictures is the optical proximity effect (not to be confused with the proximity (gap) effect in contact lithography); corners are rounded, and the smallest lines show a different width for the central line compared to the outer ones. ''Optical Proximity Correction'' is the practice of augmenting the design in order achieve the desired size and shape in the finished print. A basic form of OPC is corner correction, also known as serifs, where a small square is added or subtracted at all corners. The last column in the table show the effect; the dots become square, and the short lines are the correct length. The effect of corner correction is significant below 2µm, but negligible above 4µm. The proximity effect on the width of the outer lines is not removed by corner correction; here so-called SRAF lines (''Sub-Resolution Assist Feature'') would be needed. | Also evident in the pictures is the optical proximity effect (not to be confused with the proximity (gap) effect in contact lithography); corners are rounded, and the smallest lines show a different width for the central line compared to the outer ones. ''Optical Proximity Correction'' is the practice of augmenting the design in order achieve the desired size and shape in the finished print. A basic form of OPC is corner correction, also known as serifs, where a small square is added or subtracted at all corners. The last column in the table show the effect; the dots become square, and the short lines are the correct length. The effect of corner correction is significant below 2µm, but negligible above 4µm. The proximity effect on the width of the outer lines is not removed by corner correction; here so-called SRAF lines (''Sub-Resolution Assist Feature'') would be needed. | ||