Specific Process Knowledge/Lithography/nLOF: Difference between revisions
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'''Feedback to this section''': '''[mailto:labadviser@danchip.dtu.dk?Subject=Feed%20back%20from%20page%20http://http://labadviser.danchip.dtu.dk/index.php/Specific_Process_Knowledge/Lithography/nLOF click here]''' | '''Feedback to this section''': '''[mailto:labadviser@danchip.dtu.dk?Subject=Feed%20back%20from%20page%20http://http://labadviser.danchip.dtu.dk/index.php/Specific_Process_Knowledge/Lithography/nLOF click here]''' | ||
AZ nLOF 2020 is a negative UV photoresist, suitable for | AZ nLOF 2020 is a negative UV photoresist, suitable for lift-off processes. | ||
==Spin coating== | ==Spin coating== | ||
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The recommended PEB for nLOF is 60s at 110°C, regardless of resist film thickness. | The recommended PEB for nLOF is 60s at 110°C, regardless of resist film thickness. | ||
While 1min@110°C is adequate for Si substrates, less thermally conductive substrates (glass, III-V materials, chips bonded to carrier), have shoved problems using the standard PEB. These problems were largely solved by increasing the PEB time to 2min. Tests (on Aligner: Maskless 02) have shown that the lithographic performance of nLOF on Si is improved by using 2min@110°C PEB (less stitching, less bias, more negative profile). | While 1min@110°C is adequate for Si substrates, less thermally conductive substrates (glass, III-V materials, chips bonded to carrier), have shoved problems using the standard PEB. These problems were largely solved by increasing the PEB time to 2min. Tests (on Aligner: Maskless 02) have shown that the lithographic performance of nLOF on Si is improved by using 2min@110°C PEB (less stitching, less bias, more negative profile). A report on the tests can be seen [[media:nLOF_PEBtime_2019.pdf|here]]. | ||
==Development== | ==Development== | ||
A 2µm nLOF resist film is fully developed in 20-30s using TMAH (AZ 726). However, the development can be continued to 60s in order to get a nore negative resist profile (increase the under-cut). | A 2µm nLOF resist film is fully developed in 20-30s using TMAH (AZ 726). However, the development can be continued to 60s in order to get a nore negative resist profile (increase the under-cut). | ||