Crystallization of a-Si films with smooth surfaces by using Blue Multi-Laser Diode Annealing

2018

ECS Trans.

Laser Crystallizations using Blue Laser-Diodes Annealing (BLDA) is described for mounting the Si TFTs and the thin film functional sensors on panels. To realize high performance poly Si TFTs not only on glass but also on flexible sheets, effective laser annealing for high quality Si film by low temperature deposition is expected. To conduct a low temperature TFT process below 400°C, metal source/drain structure without using ion implantation is proposed as a low-cost fabrication. By inserting thermal buffer layers on flexible sheet, stable and effective crystallization of Si film using BLDA can be performed. High-performance CMOS TFT system with functional sensors is expected on arbitrary flexible sheets.

“…The results of surface roughness after BLDA for Si films, PE CVD films seem to have an advantage in term of smoothness than sputtered films after BLDA [16]. (8W) Fig.…”

Section: Bldamentioning

confidence: 98%

Section: Bldamentioning

confidence: 99%

(Invited) Advanced Crystallization Using Blue Laser-Diode Annealing for Low Temperature Poly Si TFTs

Noguchi

2018

ECS Trans.

“…Blue-laser-diode annealing (BLDA) was recently proposed as a new LTPS [2]. A Si film of uniform micrograins with improved electrical properties, which can hardly be formed through pulsed excimer laser annealing (ELA), can be formed reproducibly while keeping the surface smooth by adopting scanned BLDA [3]. Crystallization of the sputtered Si film even on a flexible plastic substrate using BLDA has been successfully performed [4].…”

Section: Introductionmentioning

confidence: 99%

Low-temperature poly-Si TFTs of metal source and drain using blue-laser-diode annealing (BLDA)

Sugihara¹,

Shimoda

Journal of Information Display

et al. 2017

Self Cite

Blue-laser-diode annealing (BLDA) in the continuous wave mode was performed for sputtered silicon (Si) films. Polycrystalline silicon (poly-Si) thin-film transistors (TFTs) were fabricated on a glass substrate. For the source and drain formation, titanium (Ti) was evaporated to make the metal directly contact the channel Si film without adopting n + doping. The improvement of the drain current was confirmed after hydrogen annealing at 400°C, and the typical poly-Si TFT characteristic with 50 cm 2 /Vs deduced effective carrier mobility was successfully observed. As the low-cost TFT fabrication without ion implantation becomes feasible, the low-temperature fabrication of poly-Si TFTs using BLDA is expected. ARTICLE HISTORY

“…The authors have reported blue-laser diode annealing (BLDA) as a new LTPS TFT fabrication process [10,11]. A Si film consisting of uniform micrograins with improved electrical properties can be formed reproducibly, and the surface can be kept smooth by adopting scanned BLDA for amorphous Si films [11][12][13], which can hardly be formed by the conventional pulsed ELA. For high-quality CVD Si films, anisotropic long grains along the scanning direction of the laser beam can be obtained [11,14].…”

Section: Introductionmentioning

confidence: 99%

Low-temperature poly Si TFTs via BLDA for a Ne-sputtered Si film using sputtered gate SiO₂

Noguchi

Journal of Information Display

2018

Self Cite

Amorphous SiO 2 and amorphous Si films were deposited on glass using radio frequency (RF) sputtering, and were subsequently poly-crystallized using blue-laser diode annealing (BLDA) scanned by a CW beam. Ne, which has a smaller atomic radius than Ar, was used for the sputtering of the Si film. For the gate insulator, a small amount of O 2 gas diluted with Ar was flown during the sputtering to optimize the SiO 2 film with a low leakage current. A simple TFT structure with a metal source and drain (S/D) was adopted to realize a low-temperature process with a low fabrication cost. Furthermore, to confirm the effectiveness of the sputtered gate oxide, a poly-Si TFT adopting a Si film deposited using plasma-enhanced chemical vapor deposition (PE CVD) for the channel was fabricated and was compared with the TFT with a sputtered Si film for the channel. Reasonable V g -I d characteristics were obtained for both poly-Si TFTs. The TFT structure with a metal S/D formed through a low-temperature sputtering-based process is expected to be applied to Si TFTs on an arbitrary flexible panel. ARTICLE HISTORY