Pre-thermal treatment cleaning process of wafers
AssigneeMEMC Electronic Materials, Inc.
InventorsSaeed Pirooz, Larry W. Shive
Life of this patent
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Abstract
Process for heat-treating a silicon wafer which includes the steps of contacting the surface of the silicon wafer with an aqueous solution containing hydrofluoric acid to remove metals from the wafer surface, contacting the hydrofluoric acid treated wafers with ozonated water to grow a hydrophilic oxide layer on the surface of the silicon wafer, and heating the ozonated water treated wafers to a temperature of at least about 300.degree. C. for a duration of at least about 1 second. The concentration of each of iron, chromium, calcium, titanium, cobalt, manganese, zinc and vanadium, on the surface of the silicon wafer at the initiation of the heating being less than 1.times.10.sup.9 atoms/cm.sup.2.
Claims1
A process for heat-treating a silicon wafer comprising:
- contacting the surface of the silicon wafer with an aqueous solution containing hydrofluoric acid to remove metals from the wafer surface,
- contacting the hydrofluoric acid treated wafer with ozonated water to grow a hydrophilic oxide layer on the surface of the silicon wafer, and
- heating the ozonated water treated wafer to a temperature of at least about 300.degree. C. for a duration of at least about 1 second, the concentration of each of iron, chromium, calcium, titanium, cobalt, manganese, zinc and vanadium, on the surface of the silicon wafer at the initiation of the heating being less than 1.times.10.sup.9 atoms/cm.sup.2.
Dependencies are inferred from the claim text.