Inkjet patterned ALD aluminium oxide for rear PERC metal contacts

A method of patterning atomic layer deposition (ALD) deposited aluminium oxide dielectrics (Al₂O₃) using an inkjet printer is outlined. This method has applications in creating PERC cell type rear contacts. It is simpler, and uses fewer chemicals than immersive etching techniques such as those involved in photolithography, and the patterning does not cause damage to the silicon evident in laser ablation techniques. Holes with varying diameter between 61-159 μm were etched onto a 50 nm thick ALD Al₂O₃ passivating dielectric at numerous print settings. The relationship between the printing parameters and the feature size of the holes is discussed.