Surface treatment to remove impurities in microrecesses
AssigneePurusar Corporation
InventorThomas J. Grebinski
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Abstract
A surface of an object, e.g., a semiconductor wafer, is treated to remove impurities, including those in microrecesses having minimum dimensions of ten microns or less. The object is positioned in a sealed chamber which has a limited number of potential spaceborne nucleation centers and is at a treating temperature, T. A condensable solvent is introduced into the chamber until its pressure is close to but below its vapor pressure at the temperature, T. This condition is maintained until a plurality of molecular layers of the solvent is adsorbed in the microrecesses. Then, the pressure of the solvent is increased to at least unity whereat it condenses in the microrecesses. Impurities can be removed from the microrecesses in this manner thus improving product quality.
Claims10
A method of treating a surface of an object to remove impurities in microrecesses having minimum dimensions of 10 microns or less with a condensible solvent which has a vapor pressure, P*, at a treating temperature, T, comprising:
- (1) positioning the object, with the surface exposed, within a sealed treating chamber having therein a limited number of potential spaceborne nucleation centers at said temperature, T;
- (2) introducing said solvent into said chamber until the pressure, P, of the solvent in the chamber is sufficient so that a plurality of molecular layers of the solvent is adsorbed in the microrecesses while maintaining a ratio of P/P* in the chamber below unity and below that at which substantial spaceborne nucleation of the solvent occurs;
- and
- (3) thereafter increasing the ratio, P/P*, until the solvent condenses and wets the microrecesses.
Dependencies are inferred from the claim text.