Increased doping depth of Al in wet-chemical laser doping of 4H-SiC by expanding laser pulse

Rapid photo-assisted activation and enhancement of solution-processed InZnO thin-film transistors

“…For ELA, utilizing an optical pulse stretcher (OPS) is also an important factor since performing ELA without OPS yielded µ improvement but the resulting µ was insufficient (<1 cm 2 V −1 s −1 ). The OPS extends the excimer laser pulse duration by stretching the temporal profile to prevent ablation and generate longer and more efficient laser-induced heating [24]. Employing a single ELA shot is also vital to not only reduce process complexity and process time but also to minimize laser-induced damage and easily control the total laser energy imparted to the film.…”

Formation of low resistance contacts to p-type 4H-SiC using laser doping with an Al thin-film dopant source

“…As a low-temperature doping technique, a method of applying laser irradiation to the SiC substrate in dopantcontaining gas or solution has been studied. [9][10][11][12][13][14] Recently, we have shown that it is able to form a highly doped layer by laser irradiation to an Al thin-film deposited on the 4H-SiC surface as a diffusion source. 15) In this paper, we show that very low resistance contacts can be formed by using this doping method which does not require high-temperature annealing.…”

“…The original laser pulse was expanded by using an optical pulse stretcher (OPS) to suppress the laser ablation of the surface and to increase the heat retention time by laser irradiation. 10) Ar gas blowing to the sample surface was employed to keep the surface unreacted during irradiation. After laser doping, the Al thin-film and the surface compounds were etched with phosphoric acid, CF 4 plasma, and O 2 plasma, respectively.…”

“…It is worth noting that no clear difference was found between the C-face and Siface in doping profiles produced by the laser doping. 10) Figure 3(a) shows a SEM image showing the surface of the long-pulse laser-irradiated sample after completion of the cleaning processes using plasma and BHF. The laser scanned area shows a brighter contrast than the other areas.…”