Direct patterned etching of silicon dioxide and silicon nitride dielectric layers by inkjet printing

An inkjet method for the direct patterned etching of silicon dioxide and silicon nitride dielectric is described. The method involves fewer steps, lower chemical usage and generates less hazardous chemical waste than existing resist-based patterning methods (e.g., photolithography), which employ immersion etching. Holes of diameter 40–50 μm and grooves 50–60 μm wide were etched in 300 nm silicon dioxide layers. Grooves were also etched in 75 nm silicon nitride layers formed on textured silicon surfaces. The resulting patterned dielectric layers were used to facilitate masked etching, local diffusions and metal contacting of underlying silicon for solar cell applications.