Gas-cluster ion-beam smoothing of chemo-mechanical-polish processed GaSb(10.0) substrates

• Published in: Journal of electronic materials 2003-08, Vol.32 (8), p.842-848
• Main Authors: ALLEN, L. P, TETREAULT, T. G, SUNG, C, SANTEUFEMIO, C, LI, X, GOODHUE, W. D, BLISS, D, TABAT, M, JONES, K. S, DALLAS, G, BAKKEN, D
• Format: Article
• Language: English
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Electronics; Exact sciences and technology; Materials science; Microelectronic fabrication (materials and surfaces technology); Microelectronics: LSI, VLSI, ULSI; integrated circuit fabrication technology; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Surface cleaning, etching, patterning; Surface treatments
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-003-0198-8

Authors report the gas-cluster ion-beam (GCIB) etching and smoothing of chemical-mechanical polished GaSb(100) wafers. Using a dual-energy, dual gas-cluster source process, approximately 100 nm of material was removed from a GaSb(100) surface. AFM imaging and power spectral-density analysis shows decrease in the post-GCIB root-mean-square roughness and peak-to valley measurements for the material systems. X-ray rocking-curve analysis has shown a 24-arcsec reduction in the FWHM of the (111) XRD peak of GaSb. HRTEM shows the crystallinity of the subsurface of the pre- and post-GCIB surfaces to be consistent, following the 1 x 1016 ions /cm2 total-fluence processes, with dislocation density for both pre- and post-GCIB cases below the HRTEM resolution limit. XPS indicates a strong Ga 3p electron binding-energy intensity for gallium oxide formation on the GaSb surface with the use of an O GCIB process. Analysis of the Ga 3p electron binding-energy peaks in the XPS data in conjunction with HRTEM indicates a higher Ga or GaSb content in the near surface layer (less stoichiometric-oxide presence) with use of a CF4/O2 GCIB process. The same peak analysis indicates that the surface gallium-oxide state is nearly unchanged, except in thickness, with the use of an O2-GCIB second step. The material results suggest that GCIB provides a viable method of chemo-mechanical polish damage removal on group III-V material for further device processing. 17 refs.