High-performance poly-Si thin film transistors with highly biaxially oriented poly-Si thin films using double line beam continuous-wave laser lateral crystallization

Abstract

Highly biaxially oriented poly-Si thin films were formed by double-line beam continuous-wave laser lateral crystallization (DLB-CLC). The crystallinities of the DLB-CLC poly-Si thin films were (110), (111), and (211) for the laser scan, transverse, and surface directions, respectively, and an energetically stable Σ3 grain boundary was observed to be dominant. All silicon grains were elongated in the laser scan direction and one-dimensionally very large silicon grains with lengths of more than 100 µm were fabricated. Using these biaxially oriented polycrystalline silicon (poly-Si) films, low-temperature poly-Si TFTs (LTPS-TFTs) were fabricated at low temperatures (≦550 °C) by a metal gate self-aligned process. As a result, a TFT with a high electron field effect mobility of μFE = 450 cm2 V−1 s−1 in a linear region was realized.

High Performance of Normally‐On and Normally‐Off Devices with Highly Boron‐Doped Source and Drain on H‐Terminated Polycrystalline Diamond

“…Furthermore, the uneven distribution of the impurities, defects, and grain boundaries within the channel area causes a slightly different drain current density for the same gate length. [43,44] The negative shift of the threshold voltage makes the device exhibit normally-off operation, which is mainly influenced by the nitrogen incorporation. The current technology fully utilizes the advantages of both H-termination and boron doping to achieve high-performance diamond devices, which provides a possible path for the production of multifunction and multipurpose diamond electronic devices.…”

Remarkable Improvement in Foldability of Poly‐Si Thin‐Film Transistor on Polyimide Substrate Using Blue Laser Crystallization of Amorphous Si and Comparison with Conventional Poly‐Si Thin‐Film Transistor Used for Foldable Displays

“…[24][25][26][27][28][29] In contrast, low-temperature poly-Si (LTPS) TFT backplanes on polyimide (PI) substrate have high mobility and excellent stability so that current foldable and flexible AMOLED displays are using excimer laser annealing (ELA) poly-Si TFT backplanes on PI substrates. [30][31][32][33][34][35][36][37][38][39][40][41] The crystallization of amorphous silicon (a-Si) on glass substrate can be possible by using solid phase crystallization (SPC), [42][43][44] metal-induced crystallization (MIC), [45][46][47] ELA, [48][49][50][51] and continuous wave (CW) [52][53][54][55][56][57][58][59][60][61][62][63] laser annealing. Because of no intradefects in the grains, the ELA poly-Si is widely used for the manufacturing of AMOLED and active-matrix liquid crystal display (AMLCD).…”

“…The crystallization of amorphous silicon (a‐Si) on glass substrate can be possible by using solid phase crystallization (SPC), metal‐induced crystallization (MIC), ELA, and continuous wave (CW) laser annealing. Because of no intradefects in the grains, the ELA poly‐Si is widely used for the manufacturing of AMOLED and active‐matrix liquid crystal display (AMLCD) .…”

P-7: High Performance LTPS Thin-film Transistors using Low Cost Polycrystalline Silicon by Blue Laser Annealing

“…However, in addition to its high complexity and being very expensive to establish and maintain, the ELA process is sensitive to the thickness of the a-Si film, as a consequence of the short absorption depth in the a-Si film [5]- [7]. Therefore, many crystallization methods have been suggested and researched to overcome this limitation of the ELA process, such as solid phase crystallization (SPC) [8], metal induced crystallization (MIC) [9], [10], continuous-wave (CW) green laser crystallization [11]- [13].…”