Specific Process Knowledge/Lithography/Mix-and-match: Difference between revisions
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nLOF2020 is found to work as a negative resist for both UV and EBL exposure. After EBL exposure the exposed resist exhibit sufficient contrast change to allow alignment in the MLA systems (specifically verified on MLA2). While it is possible to expose the default 1.5 µm resist layer obtained from the Gamma spin coater system with EBL, in order to obtain a resolution advantage one must dillute the resist to produce a thinner coating as described below. | nLOF2020 is found to work as a negative resist for both UV and EBL exposure. After EBL exposure the exposed resist exhibit sufficient contrast change to allow alignment in the MLA systems (specifically verified on MLA2). While it is possible to expose the default 1.5 µm resist layer obtained from the Gamma spin coater system with EBL, in order to obtain a resolution advantage one must dillute the resist to produce a thinner coating as described below. | ||
=== | ===Test process=== | ||
Resist used is nLOF2020 diluted in a ratio of 27 grams of resist mixed with 51 grams of PGMEA. The resist is spin coated on Labspin 2 at 2000 RPM for 1 min (1000 RPM/s acceleration). The wafer is then soft baked at 110C for 60 seconds. | |||
As the resist is UV sensitive exposure to white light in the EBL room is avoided by turning off the light in the room during sample mounting. | |||
A test pattern is exposed with doses from 100 to 600 µC/cm<sup>2</sup>. After EBL exposure a UV test pattern is exposed on MLA2 utilizing alignment to the exposed resist. After exposure the wafer is developed on Developer: TMAH UV-Lithography using recipe 3005, i.e. a 60 second PEB at 110C and 30 sec single puddle development cycle. | |||
===EBL results=== | |||
A contrast curve is generated using the parameters described above. | |||