Metal oxide semiconductors for a higher performance

A new technology for processing metal oxide films

Upcoming display technologies require new semiconductor materials with a higher performance than amorphous silicon (a-Si) and better suitability for large-area processes than low temperature polysilicon (LTPS). Metal oxide semiconductors are believed to fulfill this task.

In recent years, a huge effort has been made to evaluate whether sputtered metal oxides are suitable as a semiconducting layer in the TFT device. Numerous mixed-metal oxide compositions have been proven to possess unique abilities for this application. In spite of the encouraging results, several challenges for the mass production still need to be mastered, such as the contamination through the particle formation during the sputtering process, its inhomogeneity on the large areas, the change of a mixed oxide composition over the target’s lifetime and the high process and investment costs.

Evonik has found an outstanding alternative for the processing of mixed-metal oxide films. It involves an integration of unique chemistry and modern coating techniques. In the current phase, we are focusing on materials and processes for the areal coating techniques, which can be substituted by coating techniques with the option for direct patterning (“printing”) not far in the future.