An AMOLED panel using hybrid backplane technology based on p-type low temperature polycrystalline silicon (p-LTPS) and n-type indium-galliumzinc-oxide (n-IGZO) thin-film transistors (TFTs) has been successfully manufactured. New pixel and Gate-on-Array (GOA) circuits were designed and fabricated using this technology. GOA with CMOS inverter is realized by utilizing both IGZO and p-LTPS. The hybrid backplane AMOLED panel can operate between 1 and 120 Hz, which enables both high refresh rate and low standby power display applications. Furthermore, the AMOLED panel lifetime has markedly enhanced by improving IGZO TFT's uniformity and reliability.

IGZO TFT with the same on current as n-LTPS was fabricated. The saturation on current reached 1 mA, and the off-state leakage current was below 1 pA. The Vth shift under PBT / NBT stress test for the IGZO TFT was 0.1 / 0.1 V, respectively, which was better compared to the n-LTPS. Furthermore, the IGZO TFT showed an ideal Id-Vd curve (output characteristics) without any kinks. These results indicate that, a variety of backplanes, from small size smartphones to large area TVs, are possible to be made in a single factory of IGZO.

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We propose a new structure hybrid backplane technology with back contact IGZO‐TFT and LTPS. In this structure, IGZO is directly connected with intermediate metal to reduce the number of layers. The patterning process of IGZO and intermediate metal was optimized to realize superior IGZO/metal contact structure. The uniformity of contact resistance over a large area has been address for hybrid backplane. The characteristics of IGZO‐TFTs with high uniformity and reliability were confirmed. High‐quality AMOLED panels with new structure backplane have been adopted at smartphone with 6.6 in. display after severe reliability tests. We believe that the proposed structure would be useful for the mass‐production of OLED display with high quality and low cost.