• Ohuchi, Fumio S.
• Olmstead, Marjorie A.
• Yitamben, Esmeralda N.
• Joly, Alan G.
• Shamberger, Patrick J.
• Lu, Chih-Yuan
• Beck, Kenneth M.

Abstract

Phase transformation of thin film (~30 nm) ₂Se₃ /Si(111) (amorphous → crystalline) was performed by resistive annealing and the reverse transformation (crystalline → amorphous) was performed by nanosecond laser annealing. As an intrinsic-vacancy, binary chalcogenide semiconductor, ₂Se₃is of interest for non-volatile phase-change memory. Amorphous In_xSe_y was deposited at room temperature on Si(111) after pre-deposition of a crystalline ₂Se₃buffer layer (6.4 Å). Upon resistive annealing to 380°C, the film was transformed into a y-₂Se₃single crystal with its {0001} planes parallel to the Si (111) substrate and parallel to Si , as evidenced by scanning tunneling microscopy, low energy electron diffraction, and x-ray diffraction. Laser annealing with 20 nanosecond pulses (0.1 milliJoules/pulse) re-amorphized the region exposed to the laser beam, as observed with photoemission electron microscopy (PEEM). The amorphous phase in PEEM appears dark, likely due to abundant defect levels inhibiting electron emission from the amorphous In_xSe_y film.

Topics

• Deposition
• impedance spectroscopy
• single crystal
• amorphous
• phase
• x-ray diffraction
• thin film
• semiconductor
• electron microscopy
• annealing
• vacancy
• low energy electron diffraction
• scanning tunneling microscopy