Thanks Nichols, this sounds very interesting. I think we'll try this. Just so I make sure I understand: you use these millimolar solutions and mix them in equal proportions? Also, how detrimental is this solution to a standard positive photoresist such as AZ1505 (for example)? Thanks again! m On Wed, Jun 8, 2011 at 4:07 PM, Kevin Nicholswrote: > 50:25:37.5 mmol/L HF/NH4F/HNO3 at 25C gives a smooth ~13 nm / minute > in the borosilicate I use. >