Specific Process Knowledge/Lithography/EBeamLithography: Difference between revisions
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'''Feedback to this page''': '''[mailto:labadviser@ | '''Feedback to this page''': '''[mailto:labadviser@nanolab.dtu.dk?Subject=Feed%20back%20from%20page%20http://labadviser.nanolab.dtu.dk/index.php/Specific_Process_Knowledge/Lithography/EBeamLithography click here]''' | ||
<div class="keywords" style="display:none;">ebl e-beam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam writer e-beamwriter ebeamwriter e-beamlithography</div> | <div class="keywords" style="display:none;">ebl e-beam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam ebeam writer e-beamwriter ebeamwriter e-beamlithography</div> | ||
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=Performance of the e-beam writers at DTU | =Performance of the e-beam writers at DTU Nanolab= | ||
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= E-beam resists = | = E-beam resists = | ||
For info regarding E-beam resist in E-beam evaporating equiptment see here:[[http://labadviser. | For info regarding E-beam resist in E-beam evaporating equiptment see here:[[http://labadviser.nanolab.dtu.dk/index.php/Specific_Process_Knowledge/Thin_film_deposition/Wordentec#Process_information]] | ||
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography#top|Go to top of this page]]</span> | <span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography#top|Go to top of this page]]</span> | ||
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* Bring the bottle inside gowning; clean it thoroughly '''on the outside''' with water or alcohol | * Bring the bottle inside gowning; clean it thoroughly '''on the outside''' with water or alcohol | ||
* Bring the bottle to a fumehood inside the cleanroom; clean the bottle and the lid thoroughly '''on the inside''' with the main solvent of your resist. For CSAR, ZEP, mr EBL, and most PMMAs, it is anisole. If in doubt which solvent your e-beam resist contains, read the MSDS of the resist to be found [http://kemibrug.dk/searchpage/ here]. | * Bring the bottle to a fumehood inside the cleanroom; clean the bottle and the lid thoroughly '''on the inside''' with the main solvent of your resist. For CSAR, ZEP, mr EBL, and most PMMAs, it is anisole. If in doubt which solvent your e-beam resist contains, read the MSDS of the resist to be found [http://kemibrug.dk/searchpage/ here]. | ||
* If you need to dilute the resist, find a measurement beaker and clean it | * If you need to dilute the resist, find a measurement beaker and clean it thoroughly in same solvent as your own bottle. For CSAR, ZEP, mr EBL, and anisole-based PMMA, you can use the measurement beaker in the box inside the fumehood in E-4. | ||
* Let the bottle dry in the fumehood. | * Let the bottle dry in the fumehood. | ||
* Bring the (main) bottle of resist to the fumehood. Carefully unscrew the lid of the resist bottle. '''If necessary, wipe the thread of the resist bottle before you pour resist into your own bottle'''; dried resists may sit on the thread and be transferred into your bottle (or worse into the large resist bottle) when pouring. | * Bring the (main) bottle of resist to the fumehood. Carefully unscrew the lid of the resist bottle. '''If necessary, wipe the thread of the resist bottle before you pour resist into your own bottle'''; dried resists may sit on the thread and be transferred into your bottle (or worse into the large resist bottle) when pouring. | ||
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When spin coating e-beam resist, you should use a pipette to transfer resist from your bottle to the substrate. If you pour the resist directly from your bottle, you will leave resist in the thread that will soon dry out and leave particles in the resist. | When spin coating e-beam resist, you should use a pipette to transfer resist from your bottle to the substrate. If you pour the resist directly from your bottle, you will leave resist in the thread that will soon dry out and leave particles in the resist. | ||
The disposable pipettes need to be thoroughly cleaned with a N2 gun before use (app. 20 s). After some | The disposable pipettes need to be thoroughly cleaned with a N2 gun before use (app. 20 s). After some training, you can obtain particle-free 4" wafers if bottle and pipette (and spin coater) are properly cleaned. | ||
<br> | <br> | ||
Keep your resist bottles in up-right position, do not tilt or shake them too much, this can spread particles from the sidewall into the resist. | Keep your resist bottles in up-right position, do not tilt or shake them too much, this can spread particles from the sidewall into the resist. | ||
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== E-beam resists and Process flow == | == E-beam resists and Process flow == | ||
The table describes the e-beam resist used in the cleanroom for standard e-beam exposure. Some of resists are not provided by DTU Danchip and some are not yet approved for common use in the cleanroom and are currently being tested. If you wish to test some of these resists or other resists, please contact [mailto:lithography@ | The table describes the e-beam resist used in the cleanroom for standard e-beam exposure. Some of resists are not provided by DTU Danchip and some are not yet approved for common use in the cleanroom and are currently being tested. If you wish to test some of these resists or other resists, please contact [mailto:lithography@nanolab.dtu.dk Lithography]. | ||
Standard DTU Danchip resists purchased and tested by DTU | Standard DTU Danchip resists purchased and tested by DTU Nanolab: | ||
{|border="1" cellspacing="1" cellpadding="3" style="text-align:left;" width="95%" | {|border="1" cellspacing="1" cellpadding="3" style="text-align:left;" width="95%" | ||
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|- | |- | ||
|-style="background:LightGrey; color:black" | |-style="background:LightGrey; color:black" | ||
|'''[[Specific_Process_Knowledge/Lithography/ZEP520A|ZEP520A]]''' (not supplied by | |'''[[Specific_Process_Knowledge/Lithography/ZEP520A|ZEP520A]]''' (not supplied by Nanolab anymore) | ||
|Positive resist, contact [mailto:Lithography@ | |Positive resist, contact [mailto:Lithography@Nanolab.dtu.dk Lithography] if you plan to use this resist | ||
|ZEON | |ZEON | ||
|Positive resist | |Positive resist | ||
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|Positive | |Positive | ||
|[http://www.allresist.com AllResist] | |[http://www.allresist.com AllResist] | ||
|Approved, not tested yet. Used for trilayer (PE-free) resist-stack or double-layer lift-off resist stack. Please contact [mailto:Lithography@ | |Approved, not tested yet. Used for trilayer (PE-free) resist-stack or double-layer lift-off resist stack. Please contact [mailto:Lithography@nanolab.dtu.dk Lithography] for information. | ||
|[[media:AR_P617.pdf|AR_P617.pdf]] | |[[media:AR_P617.pdf|AR_P617.pdf]] | ||
|See table <u>[[Specific_Process_Knowledge/Lithography/Coaters#Coaters:_Comparison_Table|here]] </u> | |See table <u>[[Specific_Process_Knowledge/Lithography/Coaters#Coaters:_Comparison_Table|here]] </u> | ||
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|Negative | |Negative | ||
|[http://www.allresist.com AllResist] | |[http://www.allresist.com AllResist] | ||
|Both e-beam, DUV and UV-sensitive resist. Currently being tested, contact [mailto:pxshi@ | |Both e-beam, DUV and UV-sensitive resist. Currently being tested, contact [mailto:pxshi@dtu.dk Peixiong Shi] for information. | ||
|[[media:AR-N7500-7520.pdf|AR-N7500-7520.pdf]] | |[[media:AR-N7500-7520.pdf|AR-N7500-7520.pdf]] | ||
|See table <u>[[Specific_Process_Knowledge/Lithography/Coaters#Coaters:_Comparison_Table|here]] </u> | |See table <u>[[Specific_Process_Knowledge/Lithography/Coaters#Coaters:_Comparison_Table|here]] </u> | ||
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Non-standard DTU | Non-standard DTU Nanolab resists not purchased by DTU Nanolab: | ||
{|border="1" cellspacing="1" cellpadding="3" style="text-align:left;" width="95%" | {|border="1" cellspacing="1" cellpadding="3" style="text-align:left;" width="95%" | ||
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|Positive | |Positive | ||
| [http://www.allresist.com AllResist] | | [http://www.allresist.com AllResist] | ||
|We have various types of PMMA in the cleanroom. Please contact [mailto:Lithography@ | |We have various types of PMMA in the cleanroom. Please contact [mailto:Lithography@nanolab.dtu.dk Lithography] for information. | ||
| | | | ||
|See table <u>[[Specific_Process_Knowledge/Lithography/Coaters#Coaters:_Comparison_Table|here]] </u> | |See table <u>[[Specific_Process_Knowledge/Lithography/Coaters#Coaters:_Comparison_Table|here]] </u> | ||
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|Positive | |Positive | ||
|ZEON | |ZEON | ||
|Not approved. Low dose to clear, can be used for trilayer (PEC-free) resist-stack. Please contact [mailto:Lithography@ | |Not approved. Low dose to clear, can be used for trilayer (PEC-free) resist-stack. Please contact [mailto:Lithography@nanolab.dtu.dk Lithography] for information. | ||
|[[media:ZEP7000.pdf|ZEP7000.pdf]] | |[[media:ZEP7000.pdf|ZEP7000.pdf]] | ||
|See table <u>[[Specific_Process_Knowledge/Lithography/Coaters#Coaters:_Comparison_Table|here]] </u> | |See table <u>[[Specific_Process_Knowledge/Lithography/Coaters#Coaters:_Comparison_Table|here]] </u> | ||
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= Development = | = Development = | ||
There are many different developers for different E-beam resist, but since CSAR and ZEP520A are the most used at | There are many different developers for different E-beam resist, but since CSAR and ZEP520A are the most used at Nanolab, we have installed a semi automatic puddle developer: '''[[Specific_Process_Knowledge/Lithography/EBeamLithography/Developer E-beam|Developer E-beam]]''' in E-4. | ||
To accommodate most users, this tool uses developers: AR 600-546 for development of CSAR 6200 resist series and ZED N-50 for ZEP520A resists and IPA as a rinsing step. | To accommodate most users, this tool uses developers: AR 600-546 for development of CSAR 6200 resist series and ZED N-50 for ZEP520A resists and IPA as a rinsing step. | ||
Intermediate results indicate that using ZED N-50 for CSAR 6200 series resist will introduce an elevated amount of residues, and vice verva for AR 600 - 546 used on ZEP 520A, but it is inconclusive. | Intermediate results indicate that using ZED N-50 for CSAR 6200 series resist will introduce an elevated amount of residues, and vice verva for AR 600 - 546 used on ZEP 520A, but it is inconclusive. | ||
<br> | <br> | ||
We | We therefore recommend to use: | ||
*ZED N-50 for Zep520A | *ZED N-50 for Zep520A | ||
*AR 600-546 for CSAR 6200 series | *AR 600-546 for CSAR 6200 series | ||
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'''Procedure''' | '''Procedure''' | ||
# Pour developer suited for your resist into a small blue cap bottle, and label it, remember to mark it with | # Pour developer suited for your resist into a small blue cap bottle, and label it, remember to mark it with lot number, date and your name. | ||
# Leave this small bottle of developer in the fridge in Cx1 at least overnight to acclimatize. | # Leave this small bottle of developer in the fridge in Cx1 at least overnight to acclimatize. | ||
# Take the coolplate located in D3 (see picture) and connect it in Fumehood 10 (E-beam) place it on the sink-lid to keep a good airflow. | # Take the coolplate located in D3 (see picture) and connect it in Fumehood 10 (E-beam) place it on the sink-lid to keep a good airflow. | ||
# Hold left button on the front panel of the | # Hold left button on the front panel of the cool plate and set temperature with up/down arrows. | ||
# The | # The cool plate can go down to -2°C, and the fridge is +5°C hence use a beaker and pour cold developer into it and place on the coolplate, leave it to acclimatize for the desired temperature. | ||
Development time in cold development, should be subject to testing, depending on structure size and density, but is comparable with "normal" development times. | Development time in cold development, should be subject to testing, depending on structure size and density, but is comparable with "normal" development times. | ||
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== Trilayer resist stack == | == Trilayer resist stack == | ||
As an alternative to PEC, a trilayer reists stack with a thin layer of thermally evaporated Ge can be used [http://avspublications.org/jvst/resource/1/jvstal/v19/i4/p1304_s1]. This reists stack has not yet been tested at DTU Danchip. A process flow for this procedure can be found here [[media:Process_Flow_Trilayer_Ebeam_Resist.docx|Process_Flow_Trilayer_Ebeam_Resist.docx]], but please contact [mailto:Lithography@ | As an alternative to PEC, a trilayer reists stack with a thin layer of thermally evaporated Ge can be used [http://avspublications.org/jvst/resource/1/jvstal/v19/i4/p1304_s1]. This reists stack has not yet been tested at DTU Danchip. A process flow for this procedure can be found here [[media:Process_Flow_Trilayer_Ebeam_Resist.docx|Process_Flow_Trilayer_Ebeam_Resist.docx]], but please contact [mailto:Lithography@nanolab.dtu.dk Lithography] before use. | ||
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All substrates are grounded to the cassette when properly loaded. In a non-conducting substrate, the accumulation of charges in the substrates will however destroy the e-beam patterning. To avoid this, a charge dissipating layer is added on top of the e-beam resist; this will provide a conducting layer for the electrons to escape, while high-energy electrons will pass through the layer to expose the resist. | All substrates are grounded to the cassette when properly loaded. In a non-conducting substrate, the accumulation of charges in the substrates will however destroy the e-beam patterning. To avoid this, a charge dissipating layer is added on top of the e-beam resist; this will provide a conducting layer for the electrons to escape, while high-energy electrons will pass through the layer to expose the resist. | ||
If you wish to investigate the charge dissipation using other methods than below, please contact [mailto:lithography@ | If you wish to investigate the charge dissipation using other methods than below, please contact [mailto:lithography@nanolab.dtu.dk Lithography]. | ||
== ESPACER == | == ESPACER == | ||