Invited Paper PS-MoM8
Challenges in Etching of Multicomponent Oxides and Other Difficult-To-Etch Materials

Monday, October 28, 2013, 10:40 am, Room 104 C

Despite its successful implementation in industry, etching was mainly evolved empirically. Very often recipes are developed by users for specific materials. However the absence of actual scientific investigation considerably limits technology transfer. Therefore, except for a few classical materials like Si et SiO₂, only a limited amount of publications is available for unconventional materials used for example in microelectronics, photonics and telecommunications. Among these more or less exotic materials let us mention ferroelectric materials (PLZT, BST, SBT), electro-optic materials (SrTiO₃, LiNbO₃, CaBaNb₂O₆), metal-insulator transition materials (VO₂), and unconventional conductors (Pt, IrO₂, ITO, LaNiO₃).Optimizing etching processes for such materials is difficult as most of them present a low reactivity with usual etching gases such as fluorinated and chlorinated gases. Their etching is mainly governed by ion sputtering and the reactive gases forming the plasma sometimes interact with materials surface to form compounds that inhibit etching.

In this presentation, we will review the work performed by our group over the last decade on the etching of multicomponent oxides, with a particular focus on the etching of SrTiO₃ andCaBaNb₂O₆. We will also show how simulation can provide information on the redeposition of sputtered species on patterned surfaces, taking as an example the case of an unconventional conductor.