> Instead of a standard HF etch, a buffered oxide etch of NH4F (Ammonium Fluoride) in HF can be used to control the etch rate and photoresist lifting. I use app

> Instead of a standard HF etch, a buffered oxide etch of NH4F (Ammonium Fluoride) in HF can be used to control the etch rate and photoresist lifting. I use approximately 20-30g of 100% NH4F per 50mL of HF (stock whink rust remover) and etch time for 6000Å SiO2 is 20min at 20C. A couple drops of Triton X-100 nonionic surfactant may be added to the BOE to improve etch uniformity, wetting, and ensure consistency through a thicker resist. A good BOE recipe can be found here but assumes industrial-strength HF. http://sam.zeloof.xyz/sio2-patterning/ http://sam.zeloof.xyz/sio2-patterning/ See my other threads. HF is Serious Business, but approachable for the hobbyist if you know about chemical hygiene. You can buy Whink at the hardware store.