Polycrystalline silicon thin film transistors are produced by melting and recrystallizing amorphous silicon using excimer laser annealing. However, conventional annealing methods using a single excimer laser beam may produce non-uniformities due to short pulse durations that limit crystal growth. This technology uses a four excimer laser system for sequential laser firing that enables lateral silicon crystal growth, creating uniform thin film transistors with high electron mobility. As a result, this technology provides a robust method to process thin film transistors that are used in a multitude of flat panel display devices, ranging from televisions to mobile devices.
This technology improves uniformity and reduces energy consumption of silicon crystal annealing during the production of thin film transistors. Sequential excimer laser annealing creates specific heat profiles, using one laser pulse to induce melting and subsequent pulses to expand the heated region. Thus, the range of laser pulse duration is increased with low energy loss. The larger pulse duration increases crystal uniformity, and thus electron mobility, while the low energy loss improves the energy efficiency of processing larger panels. As a result, this technology improves the efficiency of producing large and highly uniform thin film transistors used in high performance display devices.
Patent Pending
Tech Ventures Reference: IR CU14158