Sputtering yield for metal halide perovskite devices patterning

Metal halide perovskites (MHPs) are emerging semiconductors with unique optoelectronic properties promising for highly rewardable applications. Water and polar solvents instability hinders the introduction of MHPs into CMOS technology infrastructure and is the main challenge for patterning and integration into electronic systems. Recently, dry etching in combination with standard lithography was demonstrated as a viable technology to address the problem. In this work, we investigate the dry etching of MHPs using argon (Ar) ion milling. Simulated etch rates using Ziegler's model are validated with experimental measurements. Assuming a linear sum of elemental sputtering yields results in total sputtering yield values for complex MHPs (CsPbIBr₂, CsPbBr₂Cl) that agree well with experimental data. Interestingly, ignoring the organic part of the hybrid halide perovskite MAPbI₂Br gives a valid estimation of the sputtering yield. At a typical processing ion energy of 700 eV, Ar milling achieves rates of approximately 1-2 nm/s across various perovskite compositions. Photodetectors (PDs) fabricated under optimized etching conditions retain typical photoresponse, demonstrating the device functionality can be preserved after etching.