Soft Pad "H1000"

Last time, we explained how the groove processing on the surface of polishing pads affects the diffusion of slurry. Here, we will introduce examples that visually verify the diffusion effect of slurry due to grooves. We prepared six different types of groove processing as samples on the polishing pad "IC1000," which has become the de facto standard for semiconductor use. - Circular Groove - Perforated Groove - Radial Groove - Spiral Groove - XY Groove - Arc Groove When a blue-colored liquid is dripped under the same conditions, it becomes clear that the diffusion of the liquid varies depending on the groove processing. It can be confirmed that the circular grooves and spiral grooves have high slurry retention, while the radial grooves and arc grooves excel in slurry discharge. Thus, even with the same polishing pad, the diffusion of slurry differs due to groove processing, which affects the action of slurry intervening with the workpieces such as wafers. Therefore, the selection of groove processing is very important. Our company can assist you in selecting groove processing while considering your process conditions and targets, so please feel free to consult with us.

Here are the steps and key points for attaching the CMP pad to the platen of the polishing device. ■ Work Procedure 1) Use a solvent such as ethanol and wipes to thoroughly clean the surface of the platen. Dirt on the platen can cause air bubbles. 2) Peel off the liner and gently place the pad on the platen. 3) Supply a small amount of pure water to the pad. 4) Use a circular roller to apply pressure to the center of the pad to adhere it. 5) While rotating the platen at 5 rpm, slowly move the roller towards the outer edge. 6) Once pressure has been applied to about half the radius, stop the platen. 7) Visually check the area where pressure has been applied to ensure there are no air bubbles. 8) After checking for air bubbles, supply pure water to maintain the wet condition of the pad. 9) Rotate the platen at 5 rpm again to continue the adhesion process. 10) After the pressure application is complete, check again for air bubbles. Then, use a brush and HPMJ for conditioning. *This is a recommended procedure, and other methods can also be used.

In selecting CMP pads, I will explain about one of the components, the groove processing. Generally, the surface of CMP pads is often grooved by the manufacturer before shipment. By applying groove processing to the surface of CMP pads, the following effects can be expected: 1. Improved retention and flowability of polishing slurry 2. Enhanced uniformity within the wafer surface and increased polishing rate 3. Prevention of wafer adhesion to the polishing pad surface 4. Discharge of processing debris and reaction byproducts The main specifications for groove processing typically include XY linear grooves, perforation grooves (through holes), and concentric grooves, and in some products, combinations of these may be possible. Various specifications for XY linear grooves, such as groove width and pitch, are available. We will select the optimal groove specifications tailored to your conditions, such as polishing equipment and processes, so please feel free to consult with us.

Silicon wafers are an important material that serves as the supporting substrate for semiconductor integrated circuits such as ICs and LSIs. There is a polishing process in the manufacturing process. In this process, scratches and impurities formed on the wafer surface up to the previous step are removed, and the wafer is processed into a high-flatness wafer without distortion. Once finished in this process, the wafer achieves a completely distortion-free mirror-like surface. For more details, please refer to our corporate website via the URL link below. ■ Silicon Wafer Polishing Case Study Before CMP, the wafer is in the state where the rough polishing as "As Lapped" has been completed, with a surface roughness of Ra=1.57nm. Through multi-step CMP processing, the surface roughness is reduced to Ra=0.22nm. - Achieving nano-level surface roughness and mirror finish - Reduction of surface defects such as scratches and particles - Improved yield