Erbium aluminum perovskite ceramics with superior plasma etching resistance

Abstract

In semiconductor industry, the ongoing miniaturization of the integrated functions on silicon wafers requires the application of harsher plasma compositions during dry etching. At the same time the requirements for cleanliness and wafer-to-wafer reproducibility increase. As a consequence, the erosion of inner wall materials releasing impurity particles into the plasma etching chamber poses a major challenge in semiconductor manufacturing. To mitigate maintenance costs and avoid wafer contamination, conventional materials such as quartz glass (SiO₂) and alumina (Al₂O₃) are gradually exchanged for materials with superior etch resistance. Recently, yttrium aluminum garnet (YAG, Y₃Al₅O₁₂) and alternative materials with garnet structure have emerged as promising candidates for this application. In the present study, erbium aluminum perovskite (ErAlO₃) was identified as a novel candidate for inner wall materials surpassing the etch resistance of erbium aluminum garnet (ErAG, Er₃Al₅O₁₂) and YAG, which were tested as reference materials in the same etch run. Reactive spark plasma sintering (RSPS) was employed for the synthesis of all specimen, which were then exposed to fluorine-based etching plasma. The erosion was characterized using scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and laser scanning microcopy.