Laser processing of transition metal oxide thin-film transistors for large-area flexible OLED displays

传统的大面积电子制造方法依赖于直接单片集成。虽然这些工艺针对硅或玻璃等坚硬的高熔点基板进行了优化，但它们可能不是制造柔性电子产品的最佳方法。在许多情况下，从热提取、机械性能、热机械行为、光学透明度、导电性或化学兼容性的角度来看，特定薄膜异质结构的理想生长衬底可能并不是理想的衬底。在这些情况下，去除生长底物可能更有利，尽管如果只涉及机械或化学方法并不总是可行的。利用透明衬底上的吸收薄膜进行激光加工已被证明是加工用于超高输出发光二极管的宽禁带器件的有效方法。脉冲激光处理提供了加热由照射区域和固体的热扩散长度定义的受控体积的材料的空间能力。这种空间控制允许薄膜结构的选择性分解，而不会影响加热区以外的周围材料。结合晶片键合工艺的选择性升空工艺将使透明衬底上的薄膜晶体管能够从原始生长衬底上移除，并集成到优化的平台上，以增强性能和功能。 拟议的研究将使金属氧化物薄膜晶体管异质集成的新方法商业化，以在塑料或布基上制造高性能柔性电子产品。这种方法将允许在一个平台上处理优化的设备，然后将其传输和集成到单独的平台上，从而增强设备功能和大面积柔性显示器的性能。

Conventional approaches to large-area electronics fabrication relies on direct monolithic integration. While optimized for rigid high-melting point substrates, such as silicon or glass, these processes may not be the best approach for fabricating flexible electronics. In many cases, the ideal growth substrate for a specific thin-film heterostructure may not be the ideal substrate from the standpoint of heat extraction, mechanical properties, thermomechanical behavior, optical transparency, electrical conductivity or chemical compatibility. In these situations, it may be more advantageous to remove the growth substrate, although it is not always practical if the approach involves only mechanical or chemical means. Laser processing using absorbing thin films on transparent substrates has been shown to be effective in processing wide-bandgap devices for ultra-high output light-emitting diodes. Pulsed-laser processing provides the spatial capability of heating a controlled volume of material defined by the irradiation area and the thermal diffusion length of the solid. This spatial control allows for selective decomposition of thin-film structures that does not affect the surrounding material outside the heating zone. A selective liftoff process combined with wafer bonding processes will enable thin-film transistors on transparent substrates to be removed from the original growth substrate and integrated onto optimized platforms to enhance performance and functionality. The research proposed will enable commercialization of novel approaches for heterogeneous integration of metal oxide thin-film transistors to manufacture high-performance flexible electronics on plastic or cloth substrates. This approach would enable optimized devices processed on one platform followed by transfer and integration onto a separate platform, enhancing device functionality and performance of large-area flexible displays.