Specific Process Knowledge/Lithography/UVLithography: Difference between revisions
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** Negative tone resist: Resist exposed to UV light will become polymerized and difficult to dissolve. The mask openings are an inverse copy of the resist pattern which is to remain on the wafer. | ** Negative tone resist: Resist exposed to UV light will become polymerized and difficult to dissolve. The mask openings are an inverse copy of the resist pattern which is to remain on the wafer. | ||
* '''Thickness of resist''': In general, it is recommended to work at or below an aspect ratio of ~1, i.e. where the width of the pattern is larger than the thickness of the resist. Furthermore, when you decide | * '''Thickness of resist''': In general, it is recommended to work at or below an aspect ratio of ~1, i.e. where the width of the pattern is larger than the thickness of the resist. Furthermore, when you decide the resist thickness, consider which transfer you need: | ||
** For <u>[[Specific_Process_Knowledge/Lithography/LiftOff|lift-off]]</u> processes, we recommend resist thickness at least 5 times larger than the thickness of the metal to be lifted. | ** For <u>[[Specific_Process_Knowledge/Lithography/LiftOff|lift-off]]</u> processes, we recommend resist thickness at least 5 times larger than the thickness of the metal to be lifted. | ||
** For dry etch or wet etch processes, investigate the resist etch rate of your process as this might limit the minimum thickness of your resist. | ** For dry etch or wet etch processes, investigate the resist etch rate of your process as this might limit the minimum thickness of your resist. | ||