Brushing – scrubbing – and general cleaning – Implements – Fabric
Reexamination Certificate
1998-11-16
2001-02-06
Gulakowski, Randy (Department: 1746)
Brushing, scrubbing, and general cleaning
Implements
Fabric
C015S230000, C015S244400, C134S022100, C134S022170, C428S131000
Reexamination Certificate
active
06182323
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to the manufacture of objects. More particularly, the present invention provides a technique including a system for manufacturing an ultraclean “scrubbing” brush or surface treatment device for the manufacture of integrated circuits, for example. Merely by way of example, the present invention is applied to a scrubbing device for the manufacture of integrated circuits. But it will be recognized that the invention has a wider range of applicability; it can also be applied to the manufacture of semiconductor substrates, hard disks, flat panel displays, and the like.
In the manufacture of electronic devices such as integrated circuits, the presence of particulate contamination, trace metals, and mobile ions on a wafer is a serious problem. Particulate contamination can cause a wide variety of problems such as electrical “opens” or “shorts” in the integrated circuit. These opens and shorts often lead to reliability and functional problems in the integrated circuit that has the opens or shorts. Mobile ion and trace metal contaminants can also lead to reliability and functional problems in the integrated circuit. The combination of these factors is the main source of lower device yields on a wafer, thereby increasing the cost of an average functional device on the wafer. In the manufacture of highly integrated devices, planarizing techniques have been used.
Chemical-mechanical polishing (“CMP”) is a commonly used technique for planarizing a film on the wafer prior to subsequent processing of the wafer. CMP often requires an introduction of a polishing slurry onto a surface of a film on the semiconductor wafer as the wafer is being mechanically polished against a rotating polishing pad. The slurries typically are water based and can contain fine abrasive particles such as silica, alumina, and other abrasive materials. After polishing is complete, the processed wafers must be cleaned to completely remove residual slurry and other residue from the polishing process in order that the surface is ready for other processing steps such as etching, photolithography, and others.
To clean residual slurry material from the surface of the polished surface, cleaning brushes have been used. These cleaning brushes are often a member that is cylindrical in shape, which generally rotates along a center axis of the cylindrical shaped member. The cleaning brushes are also often made of a foam or porous polymeric material such as polyvinyl alcohol (“PVA”). A combination of rotational movement of the brush and force or pressure placed on the brush against the wafer causes residual slurry materials to be removed from the surface of the wafer. Unfortunately, it has been found that the brushes themselves often contain residual materials from the brush manufacturing process. These residual materials include, among others, residual particles and impurities such as ions and particulate contamination. Given that brushes are often “dirty” from a manufacturer, it is often difficult to maintain cleanliness of an integrated circuit manufacturing process by using such dirty brushes.
From the above, it is seen that an improved technique for cleaning a surface treatment device is highly desired.
SUMMARY OF THE INVENTION
According to the present invention, a technique including a treatment device for cleaning surfaces is provided. In an exemplary embodiment, the present invention provides an ultraclean or microclean surface treatment device which includes a scrubbing brush for the manufacture of substrates for the electronics industry.
In a specific embodiment, the present invention provides a novel porous polymeric device, e.g., an ultraclean brush. The device includes an elongated porous polymeric member, which has an outer surface for removing residual particles from a surface of a substrate. Among other features, the member includes a polyvinyl alcohol bearing compound, where the elongated member has a calcium ion impurity concentration of less than about 1 part per million. Accordingly, the present device is much cleaner than conventional devices.
In an alternative embodiment, the present invention provides a surface treatment device. The device is a porous polymeric member including an outer surface for removing residual particles from a surface of a substrate such as a wafer or hard disk. The porous polymeric member is made of at least a polyvinyl alcohol bearing compound, which may be known as PVA, but is not limited. The porous polymeric member also has a calcium ion impurity concentration of less than about 1 part per million, and a sodium ion concentration of less than about 0.1 part per million. The porous polymeric member is substantially free from loose portions (e.g., un-cross-linked) of the porous polymeric member greater than about 1 micron in size, or greater than about 0.5 micron in size, or greater than about 0.1 micron in size.
Numerous advantages are achieved using the present invention over conventional techniques. For example, the present invention provides an ultraclean or microclean brush product in some embodiments. The present brush product is cleaner and tends to introduce fewer particles or impurities onto a substrate to be processed. Additionally, the present brush product is cleaner “out of the box.” That is, the present brush product is much cleaner on delivery than conventional products, which are now on the market at the filing date of this present application. Accordingly, the present brush product is easier to use and provides for a more efficient manufacturing process, which is important in the manufacture of integrated circuits, for example. The present invention can also be applied to other porous polymeric products. These and other advantages or benefits are described throughout the present specification and are described more particularly below.
These and other embodiments of the present invention, as well as its advantages and features are described in more detail in conjunction with the text below and attached Figs.
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Ahmed Shamim
Gulakowski Randy
Rippey Corporation
Townsend and Townsend / and Crew LLP
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