April Fools to you too,

ZnS with Ag was the common scintillator used with Ra.
This compound has a broad greenish emission wavelength from
450 - 650nm. This wavelength will not expose DNQ activated
(diazonapthoquinone) photoresist.

Our yellow room windows cut off at 450nm.
If you use ZnS with Cu you will get some more blue output
but the peak is still around 450nm. Exposure will be limited.

I think the alpha and gamma emission of the Ra itself
will crosslink the negative resist. Effect on positive resist uncertain.

Thank you for radio-'activating' the community.

Bill Flounders
Berkeley Microlab


Edward Sebesta wrote:
> Today was April 1st.
>
> ZnS or ZnSe with Radium is the pigment for glow in the dark paint. So a
> glowing wafer would expose its own resist.
>
> A little humor builds a sense of community. Or at least I hope.
>
> Ed