Treatment of semiconductor wafers
AssigneeS.O.I.Tec Silicon on Insulator Technologies
InventorsStephane Coletti, Veronique Duquennoy-Pont
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Abstract
A method is described for treating a wafer having at least a surface layer of semiconductor material, with the surface of this surface layer having undergone a chemical-mechanical polishing step followed by an RCA cleaning step. After the polishing step and prior to the RCA cleaning step, the method includes an intermediate step of cleaning the surface of the surface layer of semiconductor material using an SC1 solution under concentration and temperature conditions that allow the emergence of defects in the surface layer (curve B) to be reduced compared with a similar surface layer which has not undergone such an intermediate cleaning step (curve A).
Claims18
A method of treating a wafer having at least a surface layer of a semiconductor material, which comprises subjecting the surface of the surface layer to a chemical-mechanical polishing step, conducting an intermediate step of cleaning the surface of the surface layer of semiconductor material using an SC1 solution under concentration and temperature conditions that allow the emergence of defects in the surface layer to be reduced compared with a similar surface layer which has not undergone the intermediate cleaning step, and thereafter subjecting the surface layer to an RCA cleaning step, wherein a reduced amount of HF defects are obtained compared to the same treatment of a similar surface layer but without the intermediate cleaning step.
In the surface treatment processing of a wafer having a surface layer of a semiconductor material, the improvement which comprises conducting an intermediate cleaning step utilizing an SC1 solution that contains ammonium hydroxide (NH4OH), hydrogen peroxide (H2O2) and deionized water (H2O) but that has a reduced etching ability compared to a conventional SC1 solution in order to reduce the emergence of defects in the surface layer compared to those obtained in a similar surface layer wafer that is treated with a conventional SC1 solution.
A wafer having at least a surface layer of a semiconductor material, with the surface layer having a thickness of less than 1000 Å, a roughness of less than 2.5 Å rms for a scan area of 2 μm×2 μm, and a HF defect density of less than 0.5/cm2.
Dependencies are inferred from the claim text.