Specific Process Knowledge/Lithography/EBeamLithography/EBLProcessExamples: Difference between revisions
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=Mix-and-match with EBL and UV lithography= | =Mix-and-match with EBL and UV lithography= | ||
Using mix-and-match it is possible to combine EBL and UV lithography using selected resists. Read more on the [[Specific_Process_Knowledge/Lithography/Mix-and-match|Mix-and-match page.]] | Using mix-and-match it is possible to combine EBL and UV lithography using selected resists. Read more on the [[Specific_Process_Knowledge/Lithography/Mix-and-match|Mix-and-match page.]] | ||
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By default the subfield size is 4x4 µm. This will match for instance a beam pitch of 200 nm, since it will place 20 beam shots along each axis. It does not match a beam pitch of 190 nm for instance, since 4000 nm / 190 nm = 21.05. If one wants a beam pitch of 190 nm the subfield size should be changed to 3.990 x 3.990 µm. This is done in the JDF file by changing the '''SPPRM''' command from the usual '''SPPRM 4.0,,,,1.0,1''' to '''SPPRM 3.99,,,,1.0,1''', since the first number determines subfield size. | By default the subfield size is 4x4 µm. This will match for instance a beam pitch of 200 nm, since it will place 20 beam shots along each axis. It does not match a beam pitch of 190 nm for instance, since 4000 nm / 190 nm = 21.05. If one wants a beam pitch of 190 nm the subfield size should be changed to 3.990 x 3.990 µm. This is done in the JDF file by changing the '''SPPRM''' command from the usual '''SPPRM 4.0,,,,1.0,1''' to '''SPPRM 3.99,,,,1.0,1''', since the first number determines subfield size. | ||
A significant limitation of this approach is that the beam pitch as determined by the SHOT S command has a maximum value of 1020 units, i.e. 251 nm. The method described below does not have this limitation. | |||
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== | ==Array of small boxes approach== | ||
In this approach the pattern is an array of 2x2 nm boxes, each box will be filled with a single beam shot and hence the beam placement is determined by the boxes in the array. Thus, this is a more versatile approach as it allows the user to easily vary distance between shots and create hexagonal arrays or similar. The exposure is however somewhat slower since each shape adds a few ns of beam settling time. The beam pitch as setup in the SHOT S command should be large enough that a single beam shot is placed in each 2x2 nm box, i.e. it should just be larger than 2 nm. | |||
==Results== | ==Results== | ||
The results below are made with the approach described above. The pattern is defined in 180 nm AR-P 6200 on a silicon substrate, exposed at 29 nA. The circle size as a function of dwell time and beam pitch is illustrated in the graph. It is seen that the circle pitch has a significant impact on circle size even for the same dwell time, this is naturally due to the proximity effect and can not be avoided. The graph can however serve as a guide to chose the right combination of beam pitch and dwell time to obtain the array one desires. | |||
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