Do-hyun Kwon

9.2: LTPS 5 Mask for 3.5″ WVGA Top Emission AMOLED Displays

The world first LTPS 5 mask top emission active matrix organic light emitting diode AMOLED panel was fabricated by forming the data and the pixel in one step. Employing the coplanar structure of the pixel and the data line, we fabricated the 5 mask 3.5″ WVGA AMOLED successfully.

P‐35: 5‐Mask PMOS TFT Process Architecture for Large Size AMOLEDs

A 5-mask TFT process architecture has been developed for AMOLED backplanes. The new process has 3 less photo mask steps compared to a normal 8-mask LTPS process architecture. When compared to a TV display based on the conventional process, the 5-mask process resulted in a 14-inch AMOLED display with picture quality of nearly identical performance. for reduction of the photo mask count, an IOS capacitor structure was designed as a storage capacitor, for which no additional photo mask is needed. C-V behavior of the IOS capacitor was similar to that of an MIM C-V plot over the range of 1kHz to 1MHz. Both the integrated scan circuit and 6T-1C Vth compensation circuits have been verified to work well. A low-resistance metal bus line was also developed in order to be able to drive a 55-inch FHD AMOLED at 240Hz. It is expected that these developments will enable cost-competitive large sized AMOLED TV in the future