Our experience has shown that most as-received inter-layer dielectric and copper CMP pads suffer from gross local and global thickness uniformity problems. This non-uniformity, which may be as high as ± 50 microns for a 2,000 micron thick pad, can significantly affect within-wafer removal rate uniformity, wafer-level defects, polisher vibration and pad life.
Additionally, most individually formed pads have an intrinsic skin layer on their outer surface which occurs during the molding or pressing process. This skin layer, due to its intrinsically different mechanical and textural properties, has been shown to significantly lengthen pad seasoning and break-in procedures, thus reducing throughput, decreasing diamond disc life and increasing the overall cost of ownership.
Araca Incorporated is the exclusive agent of Toho Engineering in North America and Europe. Using Toho Engineering’s patented pad surface preparation technology, we can efficiently remove the skin layer from the surface of your pad at a control accuracy of 5 microns and a processing precision of 15 microns. The amount of material that can be skinned may be as low as 50 microns or as high as 75 percent of the initial thickness of the pad. The skinning process may be performed on both top and bottom surfaces of the pad.
The same patented technology also allows us to precisely and efficiently groove the surface of most CMP pads (regardless of their bulk mechanical properties although there may be some limitations). Grooves of virtually any design can be machined with a control accuracy of 5 microns and a processing precision of 15 microns, in all three dimensions (i.e. depth, width and pitch). Please refer to our Pad Surface Preparation and Grooving Brochure for details.
We also work with our clients to design, develop and test customized groove patterns for attaining specific thermal, mechanical, tribological, kinetic, wafer-level defects and fluid dynamics goals during the CMP process. In the case of spiral and concentric patterns, the grooves can also be slanted by as much as 40 degrees (a series of recent patents awarded to Toho Engineering) to attain certain specific polish objectives.
Our surface preparation and grooving processes are conducted at Toho Engineering’s world-class clean room facility in Mie, Japan. Within the same facility, we also provide dimensional QC services with 100% sampling including surface roughness, groove width, depth and pitch. Please refer to our Pad QC Brochure for details.
Please contact us with any questions.