Cleaning Systems—Bevel ETCH

Yield loss at the wafer edge has been a historic challenge for 3D NAND, DRAM, MEMS and advanced logic processes, with wafer edge peeling, particles and residue resulting in wafer edge yield loss during the manufacturing process. These advanced devices require precise removal of any particulates and other potentially damaging material residue during bevel etch and clean. Our Bevel Etch tool was developed to overcome these issues to optimize overall process yield. We leveraged our strong wet processing expertise to develop a system that delivers better performance than dry approaches, while minimizing chemical consumption.

Our Bevel Etch tool uses a wet etch method to remove various types of dielectric, metal and organic material films, as well as particulate contaminants on the wafer edge. Using wet etch also avoids the arcing and silicon damage risk from the dry process. The bevel etch process is performed in the front end before copper metallization and in the back end after copper metallization. ACM attains superior results with our single-wafer Bevel Etch system, which combines bevel and backside cleaning.

The system centers and aligns the wafer automatically on the vacuum chuck prior to cleaning –a significant competitive advantage. Once centered, our system performs bevel clean on the wafer. As the wafer spins, ACM performs non-contact cleaning. This approach minimizes the impact of edge contamination for subsequent process steps and improves chip manufacturing yield. After the bevel clean there is an inspection system to check the undercut before the wafer is flipped to clean the backside

Major Benefits

• Supports a range of device types and process steps for 3D NAND etch, DRAM, advanced logic processes and MEMS structures
• Highly accurate and efficient wafer center alignment to achieve precise bevel etch
• Low chemical consumption for a lower total cost of ownership.

Features and Specifications

• Variable wafer bevel etch/cut accuracy of 1-7mm
• Good uniformity of +/-0.1mm
• Controllable etch selectivity
• Bevel SC1 and DHF etch
• Customizable with other chemistries