Reduction in dislocation density and strain in GaN thin films grown via maskless pendeo-epitaxy

• Autorzy: Roskowski A. M. , Preble E. A. , Einfeldt S. , Miraglia P. M. , Schuck J. , Grober R. , Davis R. F.
• Języki publikacji: EN

Abstrakty

EN

Maskless pendeo-epitaxy (PE) involves the lateral and, commonly, the vertical growth of cantilevered “wings” of material from the side-walls of unmasked etched forms. Cross-sectional SEM micrographs revealed that films grown at 1020 C exhibited similar vertical [0001] and lateral [1120] growth rates. Increasing the temperature increased the latter due to the higher thermal stability of the GaN(1120). The (1120) surface was atomically smooth under all growth conditions with an RMS = 0.17 nm. High resolution X-ray diffraction (HRXRD) and atomic force microscopy of the PE films confirmed transmission electron microscopy results regarding the reduction in dislocation density in the wings. Measurement of strain indicated that the wing material is crystallographically relaxed as evidenced by the increase in the c-axis lattice parameter and the upward shift of the E2 Raman line frequency. However, tilting of the wings of ≤ 0.15 occurred due to the tensile stresses in the stripes induced by the mismatch in the coefficients of thermal expansion between the GaN and the underlying substrate.

Słowa kluczowe

EN

pendeo-epitaxy; gallium nitride; metalorganic vapour phase; lateral growth rate; vertical grovth rate; dislocations; strain; relaxation; wing tilting; atomic force microscopy (AFM); X-ray diffraction; photoluminescence; Raman

• Wydawca: Stowarzyszenie Elektryków Polskich ; Polska Akademia Nauk ; Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
• Czasopismo: Opto-Electronics Review
• Rocznik: 2002
• Tom: Vol. 10, No. 4
• Strony: 262--270
• Opis fizyczny: Bibliogr.45 poz.

Twórcy

autor

Roskowski A. M.

• Department of Chemical Engineering, Box 7919, North Carolina State University, Raleigh, NC 27695, USA

autor

Preble E. A.

• Department of Materials Science and Engineering, Box 7907, North Carolina State University, Raleigh, NC 27695, USA

autor

Einfeldt S.

• Department of Materials Science and Engineering, Box 7907, North Carolina State University, Raleigh, NC 27695, USA
• Institute of Solid State Physics, P.O. Box 330440, University of Bremen, 28334 Bremen, Germany

autor

Miraglia P. M.

• Department of Materials Science and Engineering, Box 7907, North Carolina State University, Raleigh, NC 27695, USA

autor

Schuck J.

• Department of Applied Physics, Yale University, New Haven, CT 06520, USA

autor

Grober R.

• Department of Applied Physics, Yale University, New Haven, CT 06520, USA

autor

Davis R. F.

• Department of Materials Science and Engineering, Box 7907, North Carolina State University, Raleigh, NC 27695, USA

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