Photomasks Explained (Contact and Projection): how to etch Thin Chromium Layers 

This Channel is pure Gold. Thank you very much for sharing those rare insights

big fan of all your videos, thank you for putting out such well explained and detailed content!

Thanks for putting this together. Very educational.

very smart way to remove Chromium, thank you for sharing.

It is very unusual to see somebody handles a mask without gloves ☺️

I bought a quartz photomask from a 1998 TSMC batch. I bought on Ebay. Its my favorite trinket.

I had got some masks to try and remove the chromium from. Found a Q-switched 355nm laser worked nice, ablated the chrome while leaving the quartz untouched, though this slow to the point to being useless. I ended up using the mask as a work surface in my furnace.

I have this question Huygens optics, how on earth this they made those billions of transistor patters in that photo mask. Thank you for the video.

That's a very cool hack for a fume cupboard ! Really interesting about how the Pellicle de-focusses dust particles; reading about pellicles in semi-conductor / chip manufacturing I get a lot of oddly conflicting information (will eventually did deeper). In my 20's I did a lot of odd chemical mixing under heat that looking back I shake my head at. Is it possible to lap the Chromium layer off a quartz plate ? I know some fiducials on plates can be (skillfully) removed with a scalpel. And not to ask too many questions how do you / one know if one has a glass plate or a quartz plate ? Is there a quick test for that / tell tale signs before one has to measure refractive indices or analyze spectra etc. ? Thanks again for making these amazing videos.

how on earth did you manage to get those masks

I have a question: Is there any significant lens between the photomask and silicon wafer during the lithography or patterns of photomasks are real size? I think we can't design life-size patterns on the surface of photomasks because as you said, the scale that we're talking about is in order of nanometers!

i have designed my devices, how to make mask for my devices. Is it possible to make mask using laser writing? i want to make mask for mask aligner. kindly suggest?

Where would one get his hands on some liquid photoresist suitible for this kind of thing?

Ammonia is a weak base, but very powerful when concentrated ;-)

As i was listening to this I was wondering whether I've ended up at at the right channel, apparently not

Thanks for this video)

Very interesting! What wavelength do you think was used for the original mask, EUV? Your video as always was great.

Why do you have such thick missive granite table?

Why did you not use a Standart Cr-etch as it is sold at microchemical for exampel?

But how is the first one made? I mean so lets say they designed a new chip. How would they take that CAD version of it and write it to the wafer? I dont understands.

Why are you removing chromium from a sheet of quartz glass? Wht not buy a sheet of clear glass?

Please wearing poly globe~