Liquid-assisted cryogenic cleaning
AssigneeBOC Limited
InventorsSouvik Banerjee, Harlan Forrest Chung
Life of this patent
Estimating the term…
Abstract
The present invention is directed to the use of a high vapor pressure liquid prior to or simultaneous with cryogenic cleaning to remove contaminants from the surface of substrates requiring precision cleaning such as semiconductors, metal films, or dielectric films. A liquid suitable for use in the present invention preferably has a vapor pressure above 5 kPa and a freezing point below −50° C.
Claims21
A process for the removal of contaminants from a substrate surface requiring precision cleaning, comprising the steps of:
- a) applying a high vapor pressure liquid to the substrate surface;
- and b) cryogenically cleaning the surface of the substrate;
- to remove contaminants from the substrate surface.
A process of cleaning the surface of a semiconductor or dielectric film comprising the steps of:
- a) spraying a high vapor pressure liquid onto the surface;
- b) spraying a liquid CO2 stream through a nozzle to form a gaseous CO2 stream having solid CO2 particles, and c) directing said stream at the surface;
- thereby removing contaminants from the surface.
A process for cleaning a surface of a semiconductor or dielectric film to remove contaminants having a particle size of about 0.76 μm or less, comprising the steps of:
- a) spraying a high vapor pressure liquid, having a vapor pressure of 5kPa or greater and a freezing point of about −50° C. or less, in thin layers onto the surface;
- b) leaving the liquid on the surface for at least one minute, prior to the initiation of cryogenic cleaning of the surface.
A process for cleaning a surface of a semiconductor or dielectric film to remove contaminants having a particle size of about 0.76 μm or less, comprising the steps of:
- a) spraying a high vapor pressure liquid, having a vapor pressure of 5 kPa or greater and a freezing point of about −50° C. or less, in thin layers onto the surface;
- simultaneously with cryogenic cleaning of the surface.
Dependencies are inferred from the claim text.