Formation of ultrathin amorphized Si layer by femtosecond laser irradiation is reported in this letter. Below the fluence of ablation threshold, femtosecond laser irradiation induced an amorphization of crystalline Si. The authors confirmed the thickness of amorphous Si layer by transmission electron microscope. The thickness of the amorphized layer was found to be quite uniform and did not depend on the number of irradiated laser pulses and fluence, which was related to the effective light penetration depth.
The ablation and amorphization of crystalline Si by femtosecond and picosecond laser irradiations are reported in this paper. Laser pulse width was varied in the range of 100 fs–200 ps. We obtained the dependences of ablation rate and fluence for amorphization on laser pulse width. At a lower fluence than a single-shot ablation threshold, femtosecond laser irradiation induced the amorphization of crystalline Si. We confirmed the thickness of an amorphous Si layer by transmission electron microscopy. The thickness of an amorphized layer, which was about 50 nm and almost uniform, did not depend on the number of irradiated laser pulses and fluence. The fluence range for amorphization decreased with increasing laser pulse width.
Articles you may be interested inPerformance of thermal cavitation technique for fuel loading in spherical cryogenic foam target for laser fusion J. Vac. Sci. Technol. A 9, 2140 (1991); 10.1116/1.577240 A novel technique to make foam shells with high sphericity and wall uniformity for cryogenic laser fusion targets J. Vac. Sci. Technol. A 9, 820 (1991); 10.1116/1.577322 Development of foam shells for cryogenic laser fusion target
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.