[Abstract]

Semiconductors have been extensively studied for over a century, and some of them are already used in commercial electronics. The rapid development in the electronics industry has been successful due to the significant efforts in various research fields: electronic devices, circuits, semiconductor physics, etc. These fields have various goals with different motivating factors but are closely related to each other. South Korea has entered a critical period in which the industrial paradigm should shift to the development of fundamental technologies. There is now a demand for young scientists to make new discoveries, making it critical for scientists to have a comprehensive understanding and perspective of a wide range of scientific fields. In this lecture, recent flat-panel display (FPD) technologies will be introduced as an example that shows how a new material, amorphous oxide semiconductor, has largely changed the direction of FPD industries. This lecture will be helpful for the students who are involved in the fields of electrical engineering and materials science. It is suggested to briefly review the below publications before attending this lecture.

Since the publication of the seminal paper by Nomura, et al. in 2004, the amorphous oxide-based semiconductor materials have emerged as a strong candidate to be the backplane technology for next-generation LCD and OLED panels because they are cost-effective, scalable, and flexible. In particular, amorphous InGaZnO (IGZO) has been widely used as a channel material in thin film transistors (TFTs). Recently, due to their low leakage current, Low-Temperature Polycrystalline Oxid, or LTPO, is an OLED display backplane technology developed by Apple. LTPO combines both LTPS TFTs and Oxide TFTs. LTPO is applicable for both OLED and LCD displays, actually, but this backplane technology is likely to be used exclusively in high-end OLED displays. In LTPO, the switching circuits are using LTPS while the driving TFTs will use IGZO materials. This could lead to a power saving of around 5-15% compared to the currently-used LTPS backplanes. This talk will discuss the characteristics of these oxides in detail.