Dear Chiranjeevi,

Once the wafer is dried out after dicing it is hardly possible to remove the debris. So don't let your wafer dry out after dicing, keep it wet by placing it in a beaker with DI water and then ultrasonically clean it.

A better option is to protect your substrate during dicing with, for example, transparant UV foil. This prevents debris entering your trenches. After dicing, UV-expose the foil and peel it off. Other foil might work as well. 

Cover your wafer with photoresist before dicing. Remove the photoresist after rinsing away debris.

The common method will be covered layers of photoresist before dicing. I always cover the AZ photoresist continously with SU-8. Therefore， you can easily wash them away by acetone afterwards. If you need to keep your inner structure away from water, thermal paste to cover the holes is necessary.

Thank you for suggestions.  We had tried with Mylar sheet and it failed. We are now trying with MA-P 1275 photo resist. Will update you after obtaining results.

dear Lakavath, is your trench crossing the dicing lines? if so, you might need a conformal photoresist coating, i. e. spray coating, to protect during dicing.

regards

Alvise

Dear Bagolini

No, its not crossing the dicing lines. Though we got better results with MA-P 1275 (30 Micron resist height) vis-a-vis without PR coating, still some fine  Silicon debris are found on the device area. 

you can removed the debris after dicing by using a plasma treatment technology that is low temperature and low damage call Odyssey HDRF (high density radical flux)

Thank you for answer. But at present we do not have mentioned tool. To resolve this debris issue, we moved dicing street away from trench area (Design change). Thanks all of you for valuable suggestions.