RCA cleaning is to use the RCA method to clean.RCA is a typical and commonly used wet chemical cleaning method:
(4) HPM (SC-2):HCl/H2O2/H2 O from 65 to 85 DEG C is used to remove metal, iron, magnesium and other metal contamination on the surface of silicon wafer. Fe and Zn can be removed by HPM at room temperature.The first is the general idea of cleaning to remove organic contamination on silicon wafer surface, because the organic matter will cover part of the silicon surface, so that the oxide film and related contamination is difficult to remove; then the dissolution of oxide film, the oxide layer is because of "contamination trap", will also introduce epitaxial defects; finally, the removal of particulate and metal contamination, at the same time silicon surface passivation
() APM (SC-1): NH4OH/H2O2 /H2O 30 ~ 80 DEG C due to the action of H2O2, the surface of the silicon wafer has a natural oxide film (SiO2), which is hydrophilic, and the surface of the silicon wafer can be soaked with the cleaning liquid. Because the natural oxide layer on the surface of silicon wafer and the Si on the surface of silicon wafer are corroded by NH 4OH, the particles attached to the surface of the silicon wafer will fall into the cleaning liquid, so as to achieve the purpose of removing particles. At the same time, the H2O 2 forms a new oxide film on the surface of the oxidized silicon wafer when the NH4OH is etched on the surface of the silicon wafer.
(2) HF (DHF):HF (DHF) from 20 to 25 DEG C DHF can remove the natural oxide film on the surface of silicon wafer, therefore, the metal attached to the natural oxide film will be dissolved into the cleaning solution, and DHF can inhibit the formation of oxide film. Therefore, it is easy to remove Al, Fe, Zn, Ni and other metals on the surface of silicon wafer, and DHF can also remove the metal hydroxide attached to the natural oxide film. When cleaning with DHF, the silicon on the surface of the silicon wafer is not corroded when the natural oxide film is corroded.
() SPM:H2SO4 /H2O2 120 to 150 DEG C SPM has a high oxidation capacity, can be dissolved in the metal oxidation solution, and the oxidation of organic matter to generate CO 2 and H2O. The use of SPM to clean silicon wafers can remove heavy organic contaminants and some metals on the surface of silicon wafer, but it is difficult to remove organic matter when organic matter is particularly serious.
