Fiber-laser crystallization of Si films for advanced displays via the spot-beam annealing method

48‐3: Invited Paper: Fiber‐Laser Processing of Si and IGZO Films for Advanced AMOLED Displays on Gen 8 Substrates

“…The fact that essentially identical-to-the-ELA-processed material (which was painstakingly developed, refined, and optimized over the past 30 years) can be so promptly produced via SBA using completely different technical components and processing details can be understood as a consequence of the flexibility of the SBA method being leveraged in the present set-up to mimic and induce the thermal environment (which leads to grain-boundarydominated partial-melting-and-solidification transformation cycles) encountered during ELA [7,13]. In other words, according to our current physical understanding and model of the ELA method [16][17][18], as long as we create equivalent local heating and melting-and-solidification cycles while also using a sufficiently coherent beam (so as to induce the LIPSS effect [1], particularly near the late stage of the process), it should be possible to produce the "ELA-Si" films even using a set of substantially different technical elements and schemes.…”

“…Building on the basic tenets of the SBA method [4][5][6][7], a researchgrade SBA system (Fig. 1) was constructed, configured, and used in order to create the overall thermal environment encountered during the ELA method [7,13]. This system is noteworthy because it employs advanced polygon-based spot-beam-scanning optics in order to generate geometrically consistent and precisely controlled ultra-rapid scanning of the spot beam [15].…”

“…In this paper, we first focus on examining and evaluating the microstructure of the SBA-crystallized Si films obtained using the newly constructed SBA research system (Fig. 1) [13], and comparing the findings to the microstructural characteristics of the polycrystalline Si films generated using the ELA method. We then discuss the technological implications of the findings, and also suggest certain future SBA R&D activities, which include the usage of the approach to (1) execute optimal heat treatment of thin films, in general, and (2) induce topological and compositional short-range ordering [14] of amorphous indium gallium zinc oxide (a-IGZO) films, in particular.…”

67‐4: Uniform Polycrystalline Si Films Obtained via the Fiber‐laser‐based Spot‐Beam‐Annealing Method

“…In this paper, we focus on (1) characterizing and analyzing the microstructure of the SBA-crystallized Si films that were obtained using the newly constructed SBA research system (Figure 1) [13], and (2) comparing the microstructural characteristics of the SBAgenerated films to those generated using the ELA method. We discuss the technological implications of the findings and suggest possible future directions and R&D activities for the SBA technology.…”

P‐41: Experimental Study of Intrinsic Melting Mechanism and Behavior During Laser Annealing of Si Films

“…On the other hand, our result implies that the ordered-grain microstructure, which is usually believed to be unique to ELA, could be reproduced by other means, as long as a coherent irradiation source is used while also providing a similar thermal environment. Indeed, fiber-laser-induced crystallization using raster scanning of a spot beam, known as spot-beam annealing (SBA), has recently been shown to be capable of generating such a microstructure [8]. With its increased averaging effect and unprecedented flexibility for tuning the spatial and temporal energy deposition profiles, the SBA method may enable generating cheaper, yet similar-orbetter quality backplane materials for manufacturing LTPSand LTPO-based displays, particularly via SBA-based sequential lateral solidification (SLS) of the films.…”