17th International Conference on Ion Beam Modification of Materials

Font Size:  Small  Medium  Large

Self-organized nanodots on GaAs by 60 keV Ar+-ion beam sputtering

Vinay Venugopal, Sandeep Garg*, Tanmoy Basu, Dinakar Kanjilal, and Tapobrata Som

poster presentation: Monday 2010-08-23 05:00 PM - 07:00 PM in section Ion-driven self-organization, nanopatterning
Last modified: 2010-06-02

Abstract


Evolution of surface morphology on compound semiconductor surfaces by ion erosion has become an important area of research. However, knowledge on the effects of experimental parameters such as ion flux/current density, ion fluence, angle of incidence of the ion, and surface crystallographic orientation of the sample becomes crucial to optimize the process of formation self-organized nanostructures. We have chosen GaAs for its applications in opto-electronic devices based on arrays of nanostructures such as quantum dots. Nanodot formation has been reported on GaAs surfaces using 50-60 keV Ar+-ion sputtering but along with hole/pit [1] and ripple formation [2]. Nanodots with pits were observed in n-GaAs(100) for normal incidence [1], while dots on ripples were formed in case of semi-insulating (SI)-GaAs(100) for 60° off-normal incidence [2]. In this work, we implanted 60 keV Ar+-ions in p- GaAs(100) by using a current density of ~10-12 μA/cm2 for incident angles between 0°-60° and fluences (2×1017-3×1018 ions cm-2). Atomic force microscopic (AFM) studies indicate formation of nanodots (26-40 nm) without any short range ordering for 60° off-normal incidence. The largest dots are smaller by a factor of 3, as compared to the smallest dots reported in [2] on SI-GaAs(100). There is no ripple formation even at the highest fluence (3×1018 ions cm-2).

 

References

[1] S. K. Mohanta, R. K. Soni, N. Gosvami, S. Tripathy, D. Kanjilal, Appl. Surf. Sci., 253 (2007) 4531.

[2] D. Datta, S. R. Bhattacharyya, T. K. Chini, M. K. Sanyal, Nucl. Inst. and Meth. in Phys. Res. B, 193  (2002) 596.


Author(s) affiliation:
Vinay Venugopal, Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005, India, India
Sandeep Garg*, Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005, India, India
Tanmoy Basu, Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005, India, India
Dinakar Kanjilal, Inter-Univeristy Accelerator Center, Aruna Asaf Ali Marg, Delhi, India, India
Tapobrata Som, Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005, India, India

*presenting author
Conference registration is required in order to view papers.