Jingyu Wu

Try a concentration of hydrofluoric acid to clean the glass. Concentrated acid will dissolve the glass, and diluted acid can help clean.

Jingyu Wu

It depends what the particles are made of, how they got onto your substrate, and their size.

• I assume that you're working in Class 100 conditions. If not then you have little hope, IMHO...
• If your stuck particles are inorganic then the traditional cleaning routes apply - in the LCD industry, which is my experience, then 500 C 5% Decon 90 in 0.02 um (with sonication in our case) filtered DI water for 15 minutes followed by rinsing in filtered 18 megohm DI water (20 minutes), drain in air, was highly successful.
• For fingerprints, then IPA can be successful but the source of the fingerprints needs to be permanently removed from the laboratory perhaps after an FBI investigation
• Organic material can often be successfully removed with an oxygen plasma etch
• Tiny particles, van der Waals' bonded to the surface can only be removed by CMP (chemical mechanical polishing)

Dear jingyu,

You have to see your engraved patterns in Glass wafer under microscope to see how the particulate are attached to the grooves. I think that they are strongly boded to glass surface. The only remedy Yuri proposed is to clean these particulates by chemical etching or chemomecahnical polishing where one used chemical etch solutions with very fine abrasives fro alumina.

This is also a possible proposal.

Best wishes

Thank you all for your kind response and help! It seems like using HF to clean might be a good option. A small concern is, is it possible that the chemical etching would make glass surface non-uniform, which could affect the later anodic bonding? @Yuri Mirgorod

Jingyu Wu

It is necessary to select the optimal concentration experimentally.