Hi Dilek, hi list Sorry again about the downtime of the infrastructure during the day yesterday. The infrastructure of the data center I've got my rack server in was down.
Now to the topic: I've started writing down the BOM and I'm not sure whether 420 nm UV already has too much energy, although the data sheet of the DMD chip says it's ok to be operated until 400nm.
Here's the BOM: https://redmine.libresilicon.com/projects/maskless-lithography/wiki
It would be cool to get feedback on that from Texas Instruments.
Cheers David
Checking it promptly.
Sent from ProtonMail mobile
-------- Original Message -------- On Aug 11, 2021, 12:51, David Lanzendörfer wrote:
Hi Dilek, hi list Sorry again about the downtime of the infrastructure during the day yesterday. The infrastructure of the data center I've got my rack server in was down.
Now to the topic: I've started writing down the BOM and I'm not sure whether 420 nm UV already has too much energy, although the data sheet of the DMD chip says it's ok to be operated until 400nm.
Here's the BOM: https://redmine.libresilicon.com/projects/maskless-lithography/wiki
It would be cool to get feedback on that from Texas Instruments.
Cheers David
-- (__/) (='.'=) This is Ninja Bunny. (")_(") Copy and paste Bunny into your signature to help him gain world domination
Hi Yes. That's what I'm planning to do as well. The idea just was to design a bit more compact stepper, which can also be scaled up and sold for professional industrial environments, considering that the furnace costs 3200 USD and I've got to get the cash back in :-)
Cheers, lev
On Saturday, August 14, 2021 9:44:11 AM WEST Luke Kenneth Casson Leighton wrote:
Hello Everyone,
As for poly-Si etching our never-ending problem came across again:
http://sam.zeloof.xyz/second-ic/
https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32019R1148
He is probably not an European guy... And Europe aims to be on the map in terms of scientific progress... Never mind, we need no amateurs. Just spill a ton of public money onto our for-profit firms, they will solve everything in the right way. < / rant >
The problem is nitric acid, that is visible outright. The n-dopant is also likely no-go (I did not find explicitly, but knowing how the legislators think, they may crap their pants on the word "phosphorus compound"). Any idea on solving this?
Regards,
Ferenc
On 14/08/2021 14:13, David Lanzendörfer wrote:
Hi Yes. That's what I'm planning to do as well. The idea just was to design a bit more compact stepper, which can also be scaled up and sold for professional industrial environments, considering that the furnace costs 3200 USD and I've got to get the cash back in :-)
Cheers, lev
On Saturday, August 14, 2021 9:44:11 AM WEST Luke Kenneth Casson Leighton wrote:
Lets build a plasma etch system on the side then :)
Sent with ProtonMail Secure Email.
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
Ferenc Éger eegerferenc@gmail.com 14 Ağustos 2021 Cumartesi saat 08:31 tarihinde yazdı:
Hello Everyone,
As for poly-Si etching our never-ending problem came across again:
http://sam.zeloof.xyz/second-ic/
https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32019R1148
He is probably not an European guy... And Europe aims to be on the map
in terms of scientific progress... Never mind, we need no amateurs. Just
spill a ton of public money onto our for-profit firms, they will solve
everything in the right way. < / rant >
The problem is nitric acid, that is visible outright. The n-dopant is
also likely no-go (I did not find explicitly, but knowing how the
legislators think, they may crap their pants on the word "phosphorus
compound"). Any idea on solving this?
Regards,
Ferenc
On 14/08/2021 14:13, David Lanzendörfer wrote:
Hi
Yes. That's what I'm planning to do as well.
The idea just was to design a bit more compact stepper, which can also be
scaled up and sold for professional industrial environments, considering that
the furnace costs 3200 USD and I've got to get the cash back in :-)
Cheers,
lev
On Saturday, August 14, 2021 9:44:11 AM WEST Luke Kenneth Casson Leighton
wrote:
Libresilicon-developers mailing list
Libresilicon-developers@list.libresilicon.com
https://list.libresilicon.com/mailman/listinfo/libresilicon-developers
Where I just have been living for a long time laws are just there so that people can find ways around them, so yeah, besides potentially building a simple plasma etcher by using this magnetron sputter setup from Hackaday and running it in reverse, we might also try to find ways to buy those chemicals in diluted form and then turning it into a more concentrated form in our lab... hmm
On Saturday, August 14, 2021 6:47:28 PM WEST Dilek Isik Akcakaya wrote:
Lets build a plasma etch system on the side then :)
Sent with ProtonMail Secure Email.
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
Ferenc Éger eegerferenc@gmail.com 14 Ağustos 2021 Cumartesi saat 08:31
tarihinde yazdı:
Hello Everyone,
As for poly-Si etching our never-ending problem came across again:
http://sam.zeloof.xyz/second-ic/
https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32019R1148
He is probably not an European guy... And Europe aims to be on the map
in terms of scientific progress... Never mind, we need no amateurs. Just
spill a ton of public money onto our for-profit firms, they will solve
everything in the right way. < / rant >
The problem is nitric acid, that is visible outright. The n-dopant is
also likely no-go (I did not find explicitly, but knowing how the
legislators think, they may crap their pants on the word "phosphorus
compound"). Any idea on solving this?
Regards,
Ferenc
On 14/08/2021 14:13, David Lanzendörfer wrote:
Hi
Yes. That's what I'm planning to do as well.
The idea just was to design a bit more compact stepper, which can also be
scaled up and sold for professional industrial environments, considering that
the furnace costs 3200 USD and I've got to get the cash back in :-)
Cheers,
lev
On Saturday, August 14, 2021 9:44:11 AM WEST Luke Kenneth Casson Leighton
wrote:
Libresilicon-developers mailing list
Libresilicon-developers@list.libresilicon.com
https://list.libresilicon.com/mailman/listinfo/libresilicon-developers
Libresilicon-developers mailing list Libresilicon-developers@list.libresilicon.com https://list.libresilicon.com/mailman/listinfo/libresilicon-developers
Hi all I found a way around the issue, without future issues with people potentially SWATing my garage later on: AZ 9260 can be developed with AZ 400K, which is "only" Potassium based, but not in any concentration which could go boom :-) https://redmine.libresilicon.com/projects/maskless-lithography/wiki/Wiki
Cheers -lev
On Saturday, August 14, 2021 6:56:05 PM WEST David Lanzendörfer wrote:
Where I just have been living for a long time laws are just there so that people can find ways around them, so yeah, besides potentially building a simple plasma etcher by using this magnetron sputter setup from Hackaday and running it in reverse, we might also try to find ways to buy those chemicals in diluted form and then turning it into a more concentrated form in our lab... hmm
On Saturday, August 14, 2021 6:47:28 PM WEST Dilek Isik Akcakaya wrote:
Lets build a plasma etch system on the side then :)
Sent with ProtonMail Secure Email.
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
Ferenc Éger eegerferenc@gmail.com 14 Ağustos 2021 Cumartesi saat 08:31
tarihinde yazdı:
Hello Everyone,
As for poly-Si etching our never-ending problem came across again:
http://sam.zeloof.xyz/second-ic/
https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32019R1148
He is probably not an European guy... And Europe aims to be on the map
in terms of scientific progress... Never mind, we need no amateurs. Just
spill a ton of public money onto our for-profit firms, they will solve
everything in the right way. < / rant >
The problem is nitric acid, that is visible outright. The n-dopant is
also likely no-go (I did not find explicitly, but knowing how the
legislators think, they may crap their pants on the word "phosphorus
compound"). Any idea on solving this?
Regards,
Ferenc
On 14/08/2021 14:13, David Lanzendörfer wrote:
Hi
Yes. That's what I'm planning to do as well.
The idea just was to design a bit more compact stepper, which can also be
scaled up and sold for professional industrial environments, considering that
the furnace costs 3200 USD and I've got to get the cash back in :-)
Cheers,
lev
On Saturday, August 14, 2021 9:44:11 AM WEST Luke Kenneth Casson Leighton
wrote:
Libresilicon-developers mailing list
Libresilicon-developers@list.libresilicon.com
https://list.libresilicon.com/mailman/listinfo/libresilicon-developers
Libresilicon-developers mailing list Libresilicon-developers@list.libresilicon.com https://list.libresilicon.com/mailman/listinfo/libresilicon-developers
On August 14, 2021 10:29:30 PM UTC, "David Lanzendörfer" leviathan@libresilicon.com wrote:
Hi all I found a way around the issue, without future issues with people potentially SWATing my garage later on:
or raiding it because they read this mailing list and figure your garage is an easy target to obtain chemicals required for criminal activities.
l.
Hmm... Good point... I mean THAT's also a thing which can happen in China LOL
On Sunday, August 15, 2021 12:55:14 PM WEST lkcl wrote:
On August 14, 2021 10:29:30 PM UTC, "David Lanzendörfer"
leviathan@libresilicon.com wrote:
Hi all I found a way around the issue, without future issues with people potentially
SWATing my garage later on:
or raiding it because they read this mailing list and figure your garage is an easy target to obtain chemicals required for criminal activities.
l. _______________________________________________ Libresilicon-developers mailing list Libresilicon-developers@list.libresilicon.com https://list.libresilicon.com/mailman/listinfo/libresilicon-developers
On Sun, Aug 15, 2021 at 4:56 PM David Lanzendörfer < leviathan@libresilicon.com> wrote:
Hmm... Good point... I mean THAT's also a thing which can happen in China LOL
:)
perhaps researching and developing some physical security measures might be a good idea. again (sigh) you will likely run into "security through stupidit...^Wobscurity" in industry-standard measures ("if people don't know what security we put in place they couldn't possibly work it out"... rriiiight) so may actually have to ask a friendly physical pen-tester "how the hell do i secure these chemicals and make sure that the relevant authorities are immediately notified, and what evidence will they require?"
in the UK you have to have a gun safe and a firearms license, even for a black powder muzzle-loading musket, now [despite the fact that 50% of injuries during the English Civil War were actually down to people using their musket as a club, i.e. not firing the damn things at all because they ran out of black powder].
stupidity of regulations aside, actually either stopping someone entirely from successfully stealing these chemicals, or providing evidence (security camera footage) *that passes muster in a court of law* would make any authorities a lot less unhappy if they actually ever have to be called.
camera footage you have to be exceptionally careful about (and, also, not have cameras that are so expensive they actually end up being stolen to order!) because "processing" of the data (including post processing such as MPEG compression, scaling etc.) can be considered "tampering with evidence" (sigh) and a case thrown out despite it being blindingly obvious whodunnit.
l.
Hello Everyone,
Unfortunately, provision of dangerous goods not to be stolen is just one of the usual concerns. The other ones being malicious usage and improper disposal.
I remember a case in Hungary in the early 2000s when iron chloride (!!?!?) was pushed to be banned outright, explicitly referring to homemade PCBs as the reason. It was argued that hobbyists and cost-sparing SMEs dump the used solution into the sewers. They backed off only after realizing that this would only trigger a shift to "boosted" copper etchants like HCl and hydrogen peroxide, causing more harm.
Also, the problem of malicious use does not only relevant to the thief, but to the purported user as well. If someone walks in and says "I need a small amount of HF or organophosphorus or organoboron compound for DYI semiconductor construction (currently sounds very... yapp.) and I promise i don't lie about the purpose", who knows that one does not want simply get rid of one's own wife? Or just a new and still unknown way to produce drugs? These are the questions why authorities are going mad on the idea to give poisonous or explosive or chemically useful substances to anyone in general. Not to mention the current paranoia of security agencies that everyone who breaths is a terrorist suspect unless the opposite is proven by ten successive polygraph tests and a brain dissection.
Regards,
Ferenc
On 15/08/2021 18:16, lkcl wrote:
On Sun, Aug 15, 2021 at 4:56 PM David Lanzendörfer <leviathan@libresilicon.com mailto:leviathan@libresilicon.com> wrote:
Hmm... Good point... I mean THAT's also a thing which can happen in China LOL:)
perhaps researching and developing some physical security measures might be a good idea. again (sigh) you will likely run into "security through stupidit...^Wobscurity" in industry-standard measures ("if people don't know what security we put in place they couldn't possibly work it out"... rriiiight) so may actually have to ask a friendly physical pen-tester "how the hell do i secure these chemicals and make sure that the relevant authorities are immediately notified, and what evidence will they require?"
in the UK you have to have a gun safe and a firearms license, even for a black powder muzzle-loading musket, now [despite the fact that 50% of injuries during the English Civil War were actually down to people using their musket as a club, i.e. not firing the damn things at all because they ran out of black powder].
stupidity of regulations aside, actually either stopping someone entirely from successfully stealing these chemicals, or providing evidence (security camera footage) *that passes muster in a court of law* would make any authorities a lot less unhappy if they actually ever have to be called.
camera footage you have to be exceptionally careful about (and, also, not have cameras that are so expensive they actually end up being stolen to order!) because "processing" of the data (including post processing such as MPEG compression, scaling etc.) can be considered "tampering with evidence" (sigh) and a case thrown out despite it being blindingly obvious whodunnit.
l.
Wow, no!
Laws are laws especially these sensitive issues must be obeyed in my opinion.
I would build a plasma etch system.
Sent from ProtonMail mobile
-------- Original Message -------- On Aug 14, 2021, 10:56 AM, David Lanzendörfer wrote:
Where I just have been living for a long time laws are just there so that people can find ways around them, so yeah, besides potentially building a simple plasma etcher by using this magnetron sputter setup from Hackaday and running it in reverse, we might also try to find ways to buy those chemicals in diluted form and then turning it into a more concentrated form in our lab... hmm
On Saturday, August 14, 2021 6:47:28 PM WEST Dilek Isik Akcakaya wrote:
Lets build a plasma etch system on the side then :)
Sent with ProtonMail Secure Email.
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
Ferenc Éger eegerferenc@gmail.com 14 Ağustos 2021 Cumartesi saat 08:31
tarihinde yazdı:
Hello Everyone,
As for poly-Si etching our never-ending problem came across again:
http://sam.zeloof.xyz/second-ic/
https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32019R1148
He is probably not an European guy... And Europe aims to be on the map
in terms of scientific progress... Never mind, we need no amateurs. Just
spill a ton of public money onto our for-profit firms, they will solve
everything in the right way. < / rant >
The problem is nitric acid, that is visible outright. The n-dopant is
also likely no-go (I did not find explicitly, but knowing how the
legislators think, they may crap their pants on the word "phosphorus
compound"). Any idea on solving this?
Regards,
Ferenc
On 14/08/2021 14:13, David Lanzendörfer wrote:
Hi
Yes. That's what I'm planning to do as well.
The idea just was to design a bit more compact stepper, which can also be
scaled up and sold for professional industrial environments, considering that
the furnace costs 3200 USD and I've got to get the cash back in :-)
Cheers,
lev
On Saturday, August 14, 2021 9:44:11 AM WEST Luke Kenneth Casson Leighton
wrote:
Libresilicon-developers mailing list
Libresilicon-developers@list.libresilicon.com
https://list.libresilicon.com/mailman/listinfo/libresilicon-developers
Libresilicon-developers mailing list Libresilicon-developers@list.libresilicon.com https://list.libresilicon.com/mailman/listinfo/libresilicon-developers
-- (__/) (='.'=) This is Ninja Bunny. (")_(") Copy and paste Bunny into your signature to help him gain world domination
Well. I guess I still haven't gotten used to the new reality of not living in China anymore, which is to a certain degree like the wild west. Haha But considering that they're also there introducing more and more environmental protection laws, I might as well go with the time and find ways to take a bit more care of the environment.
On Sunday, August 15, 2021 12:16:01 AM WEST Dilek Isik Akcakaya wrote:
Wow, no!
Laws are laws especially these sensitive issues must be obeyed in my opinion.
I would build a plasma etch system.
Sent from ProtonMail mobile
-------- Original Message --------
On Aug 14, 2021, 10:56 AM, David Lanzendörfer wrote:
Where I just have been living for a long time laws are just there so that people can find ways around them, so yeah, besides potentially building a simple plasma etcher by using this magnetron sputter setup from Hackaday and running it in reverse, we might also try to find ways to buy those chemicals in diluted form and then turning it into a more concentrated form in our lab... hmm
On Saturday, August 14, 2021 6:47:28 PM WEST Dilek Isik Akcakaya wrote:
Lets build a plasma etch system on the side then :)
Sent with ProtonMail Secure Email.
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
Ferenc Éger eegerferenc@gmail.com 14 Ağustos 2021 Cumartesi saat 08:31
tarihinde yazdı:
Hello Everyone,
As for poly-Si etching our never-ending problem came across again:
http://sam.zeloof.xyz/second-ic/
https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32019R1148
He is probably not an European guy... And Europe aims to be on the map
in terms of scientific progress... Never mind, we need no amateurs. Just
spill a ton of public money onto our for-profit firms, they will solve
everything in the right way. < / rant >
The problem is nitric acid, that is visible outright. The n-dopant is
also likely no-go (I did not find explicitly, but knowing how the
legislators think, they may crap their pants on the word "phosphorus
compound"). Any idea on solving this?
Regards,
Ferenc
On 14/08/2021 14:13, David Lanzendörfer wrote:
Hi
Yes. That's what I'm planning to do as well.
The idea just was to design a bit more compact stepper, which can also be
scaled up and sold for professional industrial environments, considering that
the furnace costs 3200 USD and I've got to get the cash back in :-)
Cheers,
lev
On Saturday, August 14, 2021 9:44:11 AM WEST Luke Kenneth Casson Leighton
wrote:
Libresilicon-developers mailing list
Libresilicon-developers@list.libresilicon.com
https://list.libresilicon.com/mailman/listinfo/libresilicon-developers
Libresilicon-developers mailing list Libresilicon-developers@list.libresilicon.com https://list.libresilicon.com/mailman/listinfo/libresilicon-developers
-- (__/) (='.'=) This is Ninja Bunny. (")_(") Copy and paste Bunny into your signature to help him gain world domination
Hi All, David,
I see that you selected a greyscale PR for photolithography, it uses TMAH based developers I do not know the range of other developers it can make use of. Can we list them? This series of PR are foreign to me. I used Shipley, AZ etc. You must not buy and use TMAH based developers at home labs due to safety reasons it is extremely toxic! Second chemical I will beware of is HF in the same way in a home environment.
Second, What is the reason for going for a grayscale PR and not a regular one?
Third, The UV range depends on the PR we will be using, the smaller the wavelength, more precise will be the features if we can use the right optical system of course (De Broglies eqn.). Because I am new to the project please let me know why we decide don this set of PRs.
As per UV range of the DLP once again this depends on the PRs to be used and because DLP works by reflection, you may loose power due to reflectance, absorption and other optical phenomena therefore I think we need to be as precise as possible with our selections.
Let me point out: The rail system precision+ DLP resolution (not the pixel size) as an end result of multiple selections such as good focus etc+ PR thickness+ Development time + Light source wavelength + overlay reproducibility = approximately OUR RESOLUTION.
With current selections are we sure we will be able to reproduce 50 um features and have a good overlay if we need a second layer alignment on top?
Thank you,
Sent with ProtonMail Secure Email.
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
David Lanzendörfer leviathan@libresilicon.com 11 Ağustos 2021 Çarşamba saat 12:51 tarihinde yazdı:
Hi Dilek, hi list
Sorry again about the downtime of the infrastructure during the day yesterday.
The infrastructure of the data center I've got my rack server in was down.
Now to the topic:
I've started writing down the BOM and I'm not sure whether 420 nm UV already
has too much energy, although the data sheet of the DMD chip says it's ok to
be operated until 400nm.
Here's the BOM:
https://redmine.libresilicon.com/projects/maskless-lithography/wiki
It would be cool to get feedback on that from Texas Instruments.
Cheers
David
(__/)
(='.'=) This is Ninja Bunny.
(")_(")
Copy and paste Bunny into your
signature to help him gain world domination
Hi Dilek
About the choice of the PR: I just went for one which has a sufficient energy absorption within the visible UV range still tolerated by the inexpensive DMD chip chosen. Now that you pointed out the issue with TMAH I realize that my choice of PR wasn't the best. Can you suggest alternatives which do not require super toxic and dangerous developers but still work within the specified UV range of 420nm - 450nm? I'm aware how dangerous TMAH is, it even etches silicon, which I observed myself while doing some tests for the ultra low tech process flow variant, where I used it to etch the trench isolation. The absorption wave length was basically the only criteria which led me to suggest this specific resists, but as I've said, if we could collect a list of alternative resists delivering sufficient results in the above mentioned range, we HAVE TO put it onto our wiki page as well.
About the certainty of being able to reproduce 25 um (featuresize 50um -> lambda 25um): In order to be sure, we've got to build a prototype and test it :-)
Cheers, David
On Friday, August 13, 2021 8:03:33 AM WEST Dilek Isik Akcakaya wrote:
Hi All, David,
I see that you selected a greyscale PR for photolithography, it uses TMAH based developers I do not know the range of other developers it can make use of. Can we list them? This series of PR are foreign to me. I used Shipley, AZ etc. You must not buy and use TMAH based developers at home labs due to safety reasons it is extremely toxic! Second chemical I will beware of is HF in the same way in a home environment.
Second, What is the reason for going for a grayscale PR and not a regular one?
Third, The UV range depends on the PR we will be using, the smaller the wavelength, more precise will be the features if we can use the right optical system of course (De Broglies eqn.). Because I am new to the project please let me know why we decide don this set of PRs.
As per UV range of the DLP once again this depends on the PRs to be used and because DLP works by reflection, you may loose power due to reflectance, absorption and other optical phenomena therefore I think we need to be as precise as possible with our selections.
Let me point out: The rail system precision+ DLP resolution (not the pixel size) as an end result of multiple selections such as good focus etc+ PR thickness+ Development time + Light source wavelength + overlay reproducibility = approximately OUR RESOLUTION.
With current selections are we sure we will be able to reproduce 50 um features and have a good overlay if we need a second layer alignment on top?
Thank you,
Sent with ProtonMail Secure Email.
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
David Lanzendörfer leviathan@libresilicon.com 11 Ağustos 2021 Çarşamba
saat 12:51 tarihinde yazdı:
Hi Dilek, hi list
Sorry again about the downtime of the infrastructure during the day yesterday.
The infrastructure of the data center I've got my rack server in was down.
Now to the topic:
I've started writing down the BOM and I'm not sure whether 420 nm UV already
has too much energy, although the data sheet of the DMD chip says it's ok to
be operated until 400nm.
Here's the BOM:
https://redmine.libresilicon.com/projects/maskless-lithography/wiki
It would be cool to get feedback on that from Texas Instruments.
Cheers
David
(__/)
(='.'=) This is Ninja Bunny.
(")_(")
Copy and paste Bunny into your
signature to help him gain world domination
Good morning,
Greyscale PR is not a good option overall. It is meant for a different process. We will go with regular resists AZ series probably due to their process being cheaper. We can look for others too. High contrast resists are better at giving vertical sidewall.
AZ1512 1.2um thick positive 310-440 nm abs AZ9260 5-20 um thick positive 365-435 nm.
But we do not need to state these at the moment do we? We can basically say that any PR absorbing in this range would be sufficient to work with. We are not adbertising products after all :)
Semiconductor manufacturing chemicals are usually highly toxic to person and aquatic life. I see youtubers being very brave about their use without any fume hoods etc. I believe we will need to prepare a safety notice for people who are interested in the fieldnand have no idea what they are doing. You can not pour thess chems into the drain they need to be collected and sent to facilities for neutralization. Some cause cancer... Some can kill you with a drop.
Thank you,
Dilek
Sent from ProtonMail mobile
-------- Original Message -------- On Aug 13, 2021, 6:15 AM, David Lanzendörfer wrote:
Hi Dilek
About the choice of the PR: I just went for one which has a sufficient energy absorption within the visible UV range still tolerated by the inexpensive DMD chip chosen. Now that you pointed out the issue with TMAH I realize that my choice of PR wasn't the best. Can you suggest alternatives which do not require super toxic and dangerous developers but still work within the specified UV range of 420nm - 450nm? I'm aware how dangerous TMAH is, it even etches silicon, which I observed myself while doing some tests for the ultra low tech process flow variant, where I used it to etch the trench isolation. The absorption wave length was basically the only criteria which led me to suggest this specific resists, but as I've said, if we could collect a list of alternative resists delivering sufficient results in the above mentioned range, we HAVE TO put it onto our wiki page as well.
About the certainty of being able to reproduce 25 um (featuresize 50um -> lambda 25um): In order to be sure, we've got to build a prototype and test it :-)
Cheers, David
On Friday, August 13, 2021 8:03:33 AM WEST Dilek Isik Akcakaya wrote:
Hi All, David,
I see that you selected a greyscale PR for photolithography, it uses TMAH based developers I do not know the range of other developers it can make use of. Can we list them? This series of PR are foreign to me. I used Shipley, AZ etc. You must not buy and use TMAH based developers at home labs due to safety reasons it is extremely toxic! Second chemical I will beware of is HF in the same way in a home environment.
Second, What is the reason for going for a grayscale PR and not a regular one?
Third, The UV range depends on the PR we will be using, the smaller the wavelength, more precise will be the features if we can use the right optical system of course (De Broglies eqn.). Because I am new to the project please let me know why we decide don this set of PRs.
As per UV range of the DLP once again this depends on the PRs to be used and because DLP works by reflection, you may loose power due to reflectance, absorption and other optical phenomena therefore I think we need to be as precise as possible with our selections.
Let me point out: The rail system precision+ DLP resolution (not the pixel size) as an end result of multiple selections such as good focus etc+ PR thickness+ Development time + Light source wavelength + overlay reproducibility = approximately OUR RESOLUTION.
With current selections are we sure we will be able to reproduce 50 um features and have a good overlay if we need a second layer alignment on top?
Thank you,
Sent with ProtonMail Secure Email.
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
David Lanzendörfer leviathan@libresilicon.com 11 Ağustos 2021 Çarşamba
saat 12:51 tarihinde yazdı:
Hi Dilek, hi list
Sorry again about the downtime of the infrastructure during the day yesterday.
The infrastructure of the data center I've got my rack server in was down.
Now to the topic:
I've started writing down the BOM and I'm not sure whether 420 nm UV already
has too much energy, although the data sheet of the DMD chip says it's ok to
be operated until 400nm.
Here's the BOM:
https://redmine.libresilicon.com/projects/maskless-lithography/wiki
It would be cool to get feedback on that from Texas Instruments.
Cheers
David
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Good morning Dilek ^^
Fantastic! Thanks so much! I will put those resists onto the wiki page as examples for resists to use, and will mention that we'd be glad about reports of results using alternative resists within that wave length range.
And yes. I already had a discussion about the toxic chemical waste a while ago, where I made the usual joke that I'd follow "all the laws and regulations of the PRC", when I was told that I'd be in Portugal now and they'd have laws making it illegal to flush it down the toilet xD
I already checked, where the collection centers are here in Portugal and what chemicals are actually legal to buy as a private citizen.
Cheers, David
On Friday, August 13, 2021 2:49:45 PM WEST Dilek Isik Akcakaya wrote:
Good morning,
Greyscale PR is not a good option overall. It is meant for a different process. We will go with regular resists AZ series probably due to their process being cheaper. We can look for others too. High contrast resists are better at giving vertical sidewall.
AZ1512 1.2um thick positive 310-440 nm abs AZ9260 5-20 um thick positive 365-435 nm.
But we do not need to state these at the moment do we? We can basically say that any PR absorbing in this range would be sufficient to work with. We are not adbertising products after all :)
Semiconductor manufacturing chemicals are usually highly toxic to person and aquatic life. I see youtubers being very brave about their use without any fume hoods etc. I believe we will need to prepare a safety notice for people who are interested in the fieldnand have no idea what they are doing. You can not pour thess chems into the drain they need to be collected and sent to facilities for neutralization. Some cause cancer... Some can kill you with a drop.
Thank you,
Dilek
Sent from ProtonMail mobile
-------- Original Message --------
On Aug 13, 2021, 6:15 AM, David Lanzendörfer wrote:
Hi Dilek
About the choice of the PR: I just went for one which has a sufficient energy absorption within the visible UV range still tolerated by the inexpensive DMD chip chosen. Now that you pointed out the issue with TMAH I realize that my choice of PR wasn't the best. Can you suggest alternatives which do not require super toxic and dangerous developers but still work within the specified UV range of 420nm - 450nm? I'm aware how dangerous TMAH is, it even etches silicon, which I observed myself while doing some tests for the ultra low tech process flow variant, where I used it to etch the trench isolation. The absorption wave length was basically the only criteria which led me to suggest this specific resists, but as I've said, if we could collect a list of alternative resists delivering sufficient results in the above mentioned range, we HAVE TO put it onto our wiki page as well.
About the certainty of being able to reproduce 25 um (featuresize 50um -> lambda 25um): In order to be sure, we've got to build a prototype and test it :-)
Cheers, David
On Friday, August 13, 2021 8:03:33 AM WEST Dilek Isik Akcakaya wrote:
Hi All, David,
I see that you selected a greyscale PR for photolithography, it uses TMAH based developers I do not know the range of other developers it can make use of. Can we list them? This series of PR are foreign to me. I used Shipley, AZ etc. You must not buy and use TMAH based developers at home labs due to safety reasons it is extremely toxic! Second chemical I will beware of is HF in the same way in a home environment.
Second, What is the reason for going for a grayscale PR and not a regular one?
Third, The UV range depends on the PR we will be using, the smaller the wavelength, more precise will be the features if we can use the right optical system of course (De Broglies eqn.). Because I am new to the project please let me know why we decide don this set of PRs.
As per UV range of the DLP once again this depends on the PRs to be used and because DLP works by reflection, you may loose power due to reflectance, absorption and other optical phenomena therefore I think we need to be as precise as possible with our selections.
Let me point out: The rail system precision+ DLP resolution (not the pixel size) as an end result of multiple selections such as good focus etc+ PR thickness+ Development time + Light source wavelength + overlay reproducibility = approximately OUR RESOLUTION.
With current selections are we sure we will be able to reproduce 50 um features and have a good overlay if we need a second layer alignment on top?
Thank you,
Sent with ProtonMail Secure Email.
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
David Lanzendörfer leviathan@libresilicon.com 11 Ağustos 2021 Çarşamba
saat 12:51 tarihinde yazdı:
Hi Dilek, hi list
Sorry again about the downtime of the infrastructure during the day yesterday.
The infrastructure of the data center I've got my rack server in was down.
Now to the topic:
I've started writing down the BOM and I'm not sure whether 420 nm UV already
has too much energy, although the data sheet of the DMD chip says it's ok to
be operated until 400nm.
Here's the BOM:
https://redmine.libresilicon.com/projects/maskless-lithography/wiki
It would be cool to get feedback on that from Texas Instruments.
Cheers
David
(__/)
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(")_(")
Copy and paste Bunny into your
signature to help him gain world domination
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Hello Everyone,
HPR504 [1] (used back in HKUST) is usable for this purpose, as well as any other resists for g-line (436nm) exposure. As for developing HPR504, the HKUST recipes mention FHD-5 [2], which is essentially TMAH.
[1] https://people.rit.edu/deeemc/reference_13/photoresists/HPR-504 Data Sheet.pdf
[2] http://mfz140.ust.hk/msds/FHD-5 MSDS.pdf
Regards,
Ferenc
On 13/08/2021 16:04, David Lanzendörfer wrote:
Good morning Dilek ^^
Fantastic! Thanks so much! I will put those resists onto the wiki page as examples for resists to use, and will mention that we'd be glad about reports of results using alternative resists within that wave length range.
And yes. I already had a discussion about the toxic chemical waste a while ago, where I made the usual joke that I'd follow "all the laws and regulations of the PRC", when I was told that I'd be in Portugal now and they'd have laws making it illegal to flush it down the toilet xD
I already checked, where the collection centers are here in Portugal and what chemicals are actually legal to buy as a private citizen.
Cheers, David
On Friday, August 13, 2021 2:49:45 PM WEST Dilek Isik Akcakaya wrote:
Good morning,
Greyscale PR is not a good option overall. It is meant for a different process. We will go with regular resists AZ series probably due to their process being cheaper. We can look for others too. High contrast resists are better at giving vertical sidewall.
AZ1512 1.2um thick positive 310-440 nm abs AZ9260 5-20 um thick positive 365-435 nm.
But we do not need to state these at the moment do we? We can basically say that any PR absorbing in this range would be sufficient to work with. We are not adbertising products after all :)
Semiconductor manufacturing chemicals are usually highly toxic to person and aquatic life. I see youtubers being very brave about their use without any fume hoods etc. I believe we will need to prepare a safety notice for people who are interested in the fieldnand have no idea what they are doing. You can not pour thess chems into the drain they need to be collected and sent to facilities for neutralization. Some cause cancer... Some can kill you with a drop.
Thank you,
Dilek
Sent from ProtonMail mobile
-------- Original Message --------
On Aug 13, 2021, 6:15 AM, David Lanzendörfer wrote:
Hi Dilek
About the choice of the PR: I just went for one which has a sufficient energy absorption within the visible UV range still tolerated by the inexpensive DMD chip chosen. Now that you pointed out the issue with TMAH I realize that my choice of PR wasn't the best. Can you suggest alternatives which do not require super toxic and dangerous developers but still work within the specified UV range of 420nm - 450nm? I'm aware how dangerous TMAH is, it even etches silicon, which I observed myself while doing some tests for the ultra low tech process flow variant, where I used it to etch the trench isolation. The absorption wave length was basically the only criteria which led me to suggest this specific resists, but as I've said, if we could collect a list of alternative resists delivering sufficient results in the above mentioned range, we HAVE TO put it onto our wiki page as well.
About the certainty of being able to reproduce 25 um (featuresize 50um -> lambda 25um): In order to be sure, we've got to build a prototype and test it :-)
Cheers, David
On Friday, August 13, 2021 8:03:33 AM WEST Dilek Isik Akcakaya wrote:
Hi All, David,
I see that you selected a greyscale PR for photolithography, it uses TMAH based developers I do not know the range of other developers it can make use of. Can we list them? This series of PR are foreign to me. I used Shipley, AZ etc. You must not buy and use TMAH based developers at home labs due to safety reasons it is extremely toxic! Second chemical I will beware of is HF in the same way in a home environment.
Second, What is the reason for going for a grayscale PR and not a regular one?
Third, The UV range depends on the PR we will be using, the smaller the wavelength, more precise will be the features if we can use the right optical system of course (De Broglies eqn.). Because I am new to the project please let me know why we decide don this set of PRs.
As per UV range of the DLP once again this depends on the PRs to be used and because DLP works by reflection, you may loose power due to reflectance, absorption and other optical phenomena therefore I think we need to be as precise as possible with our selections.
Let me point out: The rail system precision+ DLP resolution (not the pixel size) as an end result of multiple selections such as good focus etc+ PR thickness+ Development time + Light source wavelength + overlay reproducibility = approximately OUR RESOLUTION.
With current selections are we sure we will be able to reproduce 50 um features and have a good overlay if we need a second layer alignment on top?
Thank you,
Sent with ProtonMail Secure Email.
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
David Lanzendörfer leviathan@libresilicon.com 11 Ağustos 2021 Çarşamba
saat 12:51 tarihinde yazdı:
Hi Dilek, hi list
Sorry again about the downtime of the infrastructure during the day yesterday.
The infrastructure of the data center I've got my rack server in was down.
Now to the topic:
I've started writing down the BOM and I'm not sure whether 420 nm UV already
has too much energy, although the data sheet of the DMD chip says it's ok to
be operated until 400nm.
Here's the BOM:
https://redmine.libresilicon.com/projects/maskless-lithography/wiki
It would be cool to get feedback on that from Texas Instruments.
Cheers
David
(__/)
(='.'=) This is Ninja Bunny.
(")_(")
Copy and paste Bunny into your
signature to help him gain world domination
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libresilicon-developers@list.libresilicon.com
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David Lanzendörfer -
Dilek Isik Akcakaya -
Ferenc Éger -
lkcl -
Luke Kenneth Casson Leighton