Laser and electrical current induced phase transformation of In2Se3 semiconductor thin film on Si(111)

Phase transformation of thin film (∼30 nm) In2Se3/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, In2Se3 is of interest for non-volatile phasechange memory. Amorphous InxSey was deposited at room temperature on Si(111) after pre-deposition of a crystalline In2Se3 buffer layer (0.64 nm). Upon resistive annealing to 380°C, the film was transformed into a γ -In2Se3 single crystal with its {0001} planes parallel to the Si(111) substrate and (112̄0) parallel to Si(11̄0), as evidenced by scanning tunneling microscopy, low energy electron diffraction, and X-ray diffraction. Laser annealing with 20-ns pulses (0.1 millijoules/pulse, fluence ≤ 50 mJ/cm2) re-amorphized C.-Y. Lu Intel Corporation, 5200 NE Elam Young Parkway, Hillsboro, OR 97124, USA P.J. Shamberger · F.S. Ohuchi Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195-2120, USA E.N. Yitamben · M.A. Olmstead Department of Physics, University of Washington, Seattle, WA 98195-1560, USA K.M. Beck ( ) W.R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, PO Box 999 K8-88, Richland, WA 99352, USA e-mail: [email protected] A.G. Joly Fundamental and Computational Sciences, Pacific Northwest National Laboratory, PO Box 999 K8-88, Richland, WA 99352, USA 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 InxSey film. PACS 61.72.Ff · 61.80.Ba · 61.82.Fk · 64.70.Kg · 68.35.Rh · 68.55.Ag