In:
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena, American Vacuum Society, Vol. 27, No. 3 ( 2009-05-01), p. 1635-1640
Abstract:
The authors report properties of a-plane ZnO films on r-plane sapphire substrates by plasma-assisted molecular beam epitaxy in which two-step growth is employed. They show that the two-step growth is effective in improving structural and optical properties of a-plane ZnO films. Here, the two-step growth is preceded by growing the first layer under Zn-rich (O-rich) conditions and growing the second layer under O-rich (Zn-rich) conditions. All the grown samples show striated anisotropic morphology. The samples with the first, thin, O-rich layer plus the second, thick, Zn-rich layer show smaller root-mean-square (rms) roughness than those with the first, thin, Zn-rich layer plus the second, thick, O-rich layer. The sample with the 20-nm-thick first layer grown under O-rich condition shows the smallest rms roughness of 1.06nm, which is a smaller rms value than that of the sample grown under the single-step, stoichiometric condition. This sample shows the highest intensity of DX0 emission at 3.392eV and small full width at half maxima of (112¯0) and (101¯1) x-ray rocking curves, which indicate the good crystal quality.
Type of Medium:
Online Resource
ISSN:
1071-1023
,
1520-8567
Language:
English
Publisher:
American Vacuum Society
Publication Date:
2009
detail.hit.zdb_id:
3117331-7
detail.hit.zdb_id:
3117333-0
detail.hit.zdb_id:
1475429-0
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