Specific Process Knowledge/Lithography/nLOF: Difference between revisions
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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 when using 2min@110°C PEB (less stitching, less bias, more negative profile). A small report on the tests can be | 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 when using 2min@110°C PEB (less stitching, less bias, more negative profile). A small report on the tests can be found [[media:nLOF_PEBtime_2019.pdf|'''here''']]. | ||
==Development== | ==Development== | ||
A 2µm nLOF resist film is fully developed in 20-30s using TMAH (AZ 726 MIF). However, the development can be continued to 60s in order to get a more negative resist profile (increase the under-cut). | A 2µm nLOF resist film is fully developed in 20-30s using TMAH (AZ 726 MIF). However, the development can be continued to 60s in order to get a more negative resist profile (increase the under-cut). | ||
Revision as of 10:09, 9 September 2022
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AZ nLOF 2020 is a negative UV photoresist, suitable for lift-off processes.
Spin coating
Post-exposure bake
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 when using 2min@110°C PEB (less stitching, less bias, more negative profile). A small report on the tests can be found here.
Development
A 2µm nLOF resist film is fully developed in 20-30s using TMAH (AZ 726 MIF). However, the development can be continued to 60s in order to get a more negative resist profile (increase the under-cut).