J. Phys. IV France 05 (1995) C5-663-C5-670
On the Use of H2 Plasma for the Cleaning and Passivation of InP SubstratesG. Bruno, M. Losurdo and P. Capezzuto
Centro di Studio per la Chimica dei Plasmi-CNR, Dipartimento di Chimica-Università di Bari, via Orabona 4, 70126 Bari, Italy
The effectiveness of hydrogen plasma for the reduction process of surface native oxide on InP substrates is investigated by X-ray photoelectron spectroscopy (XPS) and by phase modulated spectroscopic ellipsometry (PMSE). H2 plasmas, generated in a quartz tube by applying a r.f. field (13.56 MHz) to external electrodes, produce a very high H-atom flux (5-1020 atoms/cm2.sec) in the downstream region. The ex-situ XPS and in-situ PMSE measurements indicate that the native oxide layer (25 Å) is completely removed. The end point of the cleaning process is well detected by kinetic ellipsometry. The plasma treated surface shows a higher stability to reoxidation than that observed for wet etches samples.
© EDP Sciences 1995