Wet chemical cleaning of plasma oxide grown on heated (001) InP surfaces
Bogdan Lita, O Pluchery, R L. Opila, Y J. Chabal, G. Bunea, J P. Holman, E J. Bekos
Wet chemical cleaning is performed prior to most semiconductor processing steps, including epitaxial growth, metal and dielectric film deposition, and diffusion, with the purpose of removing unwanted chemical species that reside on the wafer surface. In this article, we report the results of our investigations of a specific type of residue that is formed due to the interaction between CF4/Od2 plasmas and heated (001) InP surfaces. Our studies indicate that these residues are homogeneous oxides, about 10 nm thick, and that they impede wafer processing. In addition, these "plasma oxides" do not show significant growth after removing the wafer from the plasma and storing it in ambient. Moreover, we identify several aqueous solutions, such as HF and HNO3 that can be used for the removing the plasma residues at room temperature. For example, HNOd3 and dilute HF solutions are shown to be effective in removing the plasma oxide and likely induce re-growth of oxides similar to those found on "epi-ready"-like surfaces. In general, chemical cleaning in aqueous acidic solutions tends to stabilize the surface, with little further growth of oxide in the hours following the wet chemical cleaning.
, Pluchery, O.
, Opila, R.
, Chabal, Y.
, Bunea, G.
, Holman, J.
and Bekos, E.
Wet chemical cleaning of plasma oxide grown on heated (001) InP surfaces, Journal of Vacuum Science and Technology B
(Accessed May 29, 2023)