Oxidation-resistant, easily etched Mo-Ti-Al films

In a collaborative effort with the University of Leoben, new Mo-Ti-Al films have been developed that are both oxidation-resistant and easily etched.

Jörg Winkler von der Business Unit Coating war am Forschungsprojekt beteiligt.

Molybdenum is a key component of the film system in thin-film transistors for LCD and OLED displays. In these contexts, it serves as a conductive layer or as a diffusion barrier and helps to determine the color in which a pixel lights up. Depending on the manufacturing techniques used, the molybdenum films are subject to high temperatures during the production process. However, pure molybdenum starts to oxidize at temperatures above 300 °C, and so the properties of the film suffer as a result. Titanium is therefore used to increase resistance to oxidation. But this has a disadvantage in that it becomes harder to structure the film using wet chemical etching methods.

Together with the University of Leoben, Plansee set themselves the task of developing a molybdenum film that is both oxidation-resistant and easily etched. During the course of the research project, the experts therefore replaced some of the titanium with aluminium. Mo-Al-Ti films with varying aluminium content were produced and analyzed. The best results were achieved by molybdenum films with a titanium content of 8 % and an aluminium content of at least 16 %. This makes the molybdenum film oxidation-resistant while still allowing it to be etched easily. Read the full paper here.