IMPROVED CENTER-TO-EDGE UNIFORMITY Each CMP process has inherent challenges in controlling center-to-edge uniformity. Oxide processes are typically center-slow (the wafer's edge is polished faster than the wafer's center.) Metals and prime wafer processes are typically center-fast. Only Strasbaugh's Zone Back Pressure system can enhance the center-to-edge uniformity for all CMP processes. CONTROLLED PRESSURE Strasbaugh’s Zone Back Pressure system controls the pressure applied to the back of each wafer during polishing, improving the wafer’s center-to-edge uniformity, and increasing yield. By selecting pressure zones and applying positive, negative or ambient pressure, center-to-edge uniformity is maximized. FLEXIBILITY Strasbaugh’s Zone Back Pressure can be easily adjusted to accommodate the need for back pressure zones at the wafer’s center or edge. The size of the zones may be modified by selecting one of three O-ring diameters, allowing the user to create appropriate zone sizes depending on the dimensions of the problem area. LONGER CONSUMABLES LIFE As conditioning pads age, wafer polishing becomes more center-slow. Strasbaugh’s Zone Back Pressure can be adjusted to offset such an effect, maintaining better center-to-edge uniformity and extending the life of consumables. MINIMIZED NON-UNIFORMITY Many soft, BPSG-doped oxides are center-slow. Many metal and prime wafer processes are center-fast. Zone Back Pressure can minimize center-to-edge non-uniformity in these processes. CMP PROCESSES Zone Back Pressure is production-proven for a wide range of CMP processes: Oxides Metals Prime Wafers SPECIFICATIONS Zone Back Pressure is only available with Strasbaugh’s ViPRR wafer carriers. To request more information on Strasbaugh's Zone Back Pressure system, click here.