Influence Of Particles/Impurity Metals In RCA Cleaning Solutions On Surface Contamination.

We investigated how the particles and the metals in RCA cleaning solutions contaminate wafer surfaces in 64M DRAM development process. The most dominant factor to keep the cleanliness of wafer in present process is the overall cleanliness of the system, rather than the purity of chemicals itself. The residual contamination on wafers can be kept below detection limits by optimizing the cleaning process and its operation parameters. Therefore the requirements of quality levels for the fed chemicals are supposed not so high for the present 64M DRAM development process.