Amorphization dynamics of Ge{sub 2}Sb{sub 2}Te{sub 5} films upon nano- and femtosecond laser pulse irradiation

Journal Article · Tue Jan 15 04:00:00 EST 2008 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2836788· OSTI ID:21064515

Siegel, J; Gawelda, W; Puerto, D; Dorronsoro, C; Solis, J; Afonso, C N ^[1]; Bez, R; Pirovano, A ^[2]; Wiemer, C ^[3]

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1. Instituto de Optica, CSIC, Serrano 121, E-28006 Madrid (Spain)
2. STMicroelectronics, via C. Olivetti 1, Agrate Brianza I-20041 (Italy)
3. MDM Laboratory, CNR-INFM, via C. Olivetti 2, Agrate Brianza I-20041 (Italy)

Phase transformations of crystalline Ge{sub 2}Sb{sub 2}Te{sub 5} films upon pulsed laser irradiation have been studied using in situ reflectivity measurements with temporal resolution. Two different configurations allowed point probing with nanosecond temporal resolution and imaging with subpicosecond temporal and micrometer spatial resolution. The role of the pulse duration and laser fluence on the dynamics of the phase change and the degree of amorphization is discussed. Several advantageous features of femtosecond compared to nanosecond laser-induced amorphization are identified. Moreover, a high-resolution study of the amorphization dynamics reveals the onset of amorphization at moderate fluences to occur within {approx}100 ps after arrival of the laser pulse. At high fluences, amorphization occurs after {approx}430 ps and the molten phase is characterized by an anomalously low reflectivity value, indicative of a state of extreme supercooling.

• OSTI ID: 21064515
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 2 Vol. 103; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AMORPHOUS STATE
ANTIMONY TELLURIDES
GERMANIUM TELLURIDES
GLASS
LASER RADIATION
LASERS
PHASE TRANSFORMATIONS
PULSED IRRADIATION
PULSES
REFLECTIVITY
SEMICONDUCTOR MATERIALS
SPATIAL RESOLUTION
THIN FILMS