Positive photoresist studies

please tell me in detail what u wan to do im a photolithiography xprt

I agree, somewhat, with our 'Guest'. It would require further details. However, all the information you require would be available from the manufacturer of the resist. If their spec.s are for a different lamda, then tell them what frequency you are using. They will help! Ashman

Ok, so I will explain the goal of the experiment.

I need to illuminate a positive photoresist over a stainless steel substrate in order to get some holes (after development) into the photoresist film.

When I talked with photoresists contructor, they all give me 1 parameter : the energy density in mJ/cm². Unfortunately, when I put this value with my Diode laser, the holes aren't well defined. I noticed that the energy density was given for long exposure time (approx. 10ms).

After this step, I looked for litterature on this topic, and I found the Dill's equation and parameter, and I saw that absorption is depending of exposure time (because of the bleaching aspect of a resist).

So the questions, now, are :

--> As absorption changes with the exposure time, is the energy density required for the resist changes with exposure time? (I would naturally answer yes)

--> Could we find some graphs showing the Energy density required vs Exposure time?

--> Is it possible to resolve quickly the Dill's equation?

All these questions have one goal : find a photoresist film suitable with my laser source.

Thanks,

The resist manufacturer can tell you if the frequency(wavelength) of your laser is appropriate for the resist you have. All the resists I have ever worked with have required a set frequncy range for best exposure results. You did not mention the wavelengths you are working at. There are many resist manufacturers. I am sure one of them them has a resist designed for the wavelength you have.

Yes it's right I forgot the wavelength : 375nm.

As I explained before, I would know if there's only one optical parameter : the density energy (by wavelength).

We already did some experiments and there weren't conclusive. But yesterday, we get results of other illuminations and it seems to be OK. Indeed, for my wavelength I nedd apporimately 100mJ/cm² and we did some tests changing Light power & exposure time in order to get different couples of solutions and the results were in accord with the required energy density.

Maybe, the first series was done with bad conditions (photoresist, thickness, development...)

So for me everything is OK.

Thank you for your help,