Process and device for coating the outer edge of a substrate during microelectronics manufacture
New baffles and methods of using these baffles are provided. The baffles comprise a body having an edge wall configured to direct the flow of a composition against a substrate (e.g., silicon wafer) edge. The edge wall comprises a vertical surface, a curved sidewall coupled to the vertical surface, and a lip coupled to the curved sidewall. A preferred baffle is annular in shape and formed from a synthetic resinous composition. Even more preferably, the baffle is not formed of a metal. The inventive methods comprise positioning the baffle adjacent a substrate during a spin coating process so that the edge wall causes the composition to cover the edges of the substrate and preferably a portion of the back side of the substrate.
1. A method of applying a composition to a substrate, said method comprising the steps of:
providing:
a baffle comprising a body having an edge wall, said edge wall having a curved sidewall; and
a substrate having a surface, a back surface, and an edge;
positioning said baffle and substrate so that the substrate is spaced from said edge wall;
applying a composition to said substrate surface;
rotating said substrate, such that upon rotation, said composition accumulates in said curved sidewall so as to direct the composition around and in contact with the substrate edge and to the back surface of the substrate.
2. The method of claim 1 , said edge wall comprising:
a vertical surface, said curved sidewall being coupled with said vertical surface; and
a lip coupled with said curved sidewall, said positioning step comprising positioning said substrate and baffle so that said substrate is adjacent said curved sidewall.
3. The method of claim 1 , wherein said positioning step results in said substrate being adjacent said edge wall but not in contact with said baffle.
4. The method of claim 1 , wherein said body and said edge wall are annular in shape.
5. The method of claim 1 , said edge wall defining an opening, and said substrate being positioned within said opening during said positioning step.
6. The method of claim 1 , said baffle comprising a synthetic resin composition.
7. The method of claim 1 , said substrate being a microelectronic substrate.
8. The method of claim 7 , said substrate being selected from the group consisting of silicon, silicon dioxide, silicon nitride, aluminum gallium arsenide, aluminum indium gallium phosphide, gallium nitride, gallium arsenide, indium gallium phosphide, indium gallium nitride, indium gallium arsenide, aluminum oxide, glass, quartz, polycarbonates, polyesters, acrylics, polyurethanes, papers, ceramics, and metal substrates.