Specific Process Knowledge/Lithography/UVLithography: Difference between revisions
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'''Before you plan your UV processing and request for training on any equipment in UV lithography, please go through the following steps.''' | '''Before you plan your UV processing and request for training on any equipment in UV lithography, please go through the following steps.''' | ||
If you are new to photolithography, you can visit [https://en.wikipedia.org/wiki/Photolithography this] wikipedia webpage about photolithography before you start. | If you are new to photolithography, you can visit <u>[https://en.wikipedia.org/wiki/Photolithography this]</u> wikipedia webpage about photolithography before you start. | ||
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* '''Prepare a process flow''' which describes all steps in your UV lithography process. You can find docx-templates [[Specific_Process_Knowledge/Lithography/UVLithography#Resist_Overview|in this table]]. | * '''Prepare a process flow''' which describes all steps in your UV lithography process. You can find docx-templates <u>[[Specific_Process_Knowledge/Lithography/UVLithography#Resist_Overview|in this table]]</u>. | ||
* '''Substrate pretreatment''': In many processes it is recommended to [[Specific_Process_Knowledge/Lithography/Pretreatment|pretreat or prime]] your wafer before spin-coating. In some [[Specific_Process_Knowledge/Lithography/Coaters|spin-coaters]], these pretreatment processes are included in the spin coating of resist. | * '''Substrate pretreatment''': In many processes it is recommended to </u>[[Specific_Process_Knowledge/Lithography/Pretreatment|pretreat or prime]]</u> your wafer before spin-coating. In some </u>[[Specific_Process_Knowledge/Lithography/Coaters|spin-coaters]]</u>, these pretreatment processes are included in the spin coating of resist. | ||
* '''Spin Coater''': Do you wish to use a manual spin coater or a robot spin coater? A manual spin coater is recommended for batches < 5 wafers. See a list of spin coaters [[Specific_Process_Knowledge/Lithography/Coaters|here]]. | * '''Spin Coater''': Do you wish to use a manual spin coater or a robot spin coater? A manual spin coater is recommended for batches < 5 wafers. See a list of spin coaters </u>[[Specific_Process_Knowledge/Lithography/Coaters|here]]</u>. | ||
* '''Resist Type''': Choose the type of resist you wish to use: a list of UV lithography resist types available at DTU Danchip can be found [[Specific_Process_Knowledge/Lithography/UVLithography#Resist_Overview|on this page]]. | * '''Resist Type''': Choose the type of resist you wish to use: a list of UV lithography resist types available at DTU Danchip can be found <u>[[Specific_Process_Knowledge/Lithography/UVLithography#Resist_Overview|on this page]]</u>. | ||
** Positive tone resist: Resist exposed to UV light will be dissolved in the developer. The mask openings are an exact copy of the resist pattern which is to remain on the wafer. | ** Positive tone resist: Resist exposed to UV light will be dissolved in the developer. The mask openings are an exact 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. | ** 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 for the resist thickness, consider which transfer you need: | * '''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 for the resist thickness, consider which transfer you need: | ||
** For [[Specific_Process_Knowledge/Lithography/LiftOff|lift-off]] processes, we recommend resist thickness ~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 ~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. | ||
*'''Exposure''': Choose which mask aligner you wish to use; you can find a list of mask aligners [[Specific_Process_Knowledge/Lithography/UVExposure|here]]. Consider the exposure dose. | *'''Exposure''': Choose which mask aligner you wish to use; you can find a list of mask aligners <u>[[Specific_Process_Knowledge/Lithography/UVExposure|here]]</u>. Consider the exposure dose. | ||
* '''Mask''': Design and order a photomask for your UV process. A detailed instruction on how to design and order a photomask can be found [[Specific_Process_Knowledge/Lithography/Pattern_Design_and_Mask_Fabrication|here]]. | * '''Mask''': Design and order a photomask for your UV process. A detailed instruction on how to design and order a photomask can be found <u>[[Specific_Process_Knowledge/Lithography/Pattern_Design_and_Mask_Fabrication|here]]</u>. | ||
* '''Development''': Choose which equipment you wish to use to develop your photoresist from [[Specific_Process_Knowledge/Lithography/Development|this]] list. Remember the development process (chemistry) influences the exposure dose. | * '''Development''': Choose which equipment you wish to use to develop your photoresist from <u>[[Specific_Process_Knowledge/Lithography/Development|this]]</u> list. Remember the development process (chemistry) influences the exposure dose. | ||
* '''Specify whether you wish to strip or lift-off your resist''': [[Specific_Process_Knowledge/Lithography/Strip|strip]] and [[Specific_Process_Knowledge/Lithography/LiftOff|lift-off]]. | * '''Specify whether you wish to strip or lift-off your resist''': <u>[[Specific_Process_Knowledge/Lithography/Strip|strip]]</u> and <u>[[Specific_Process_Knowledge/Lithography/LiftOff|lift-off]]</u>. | ||
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