Eliminating Salicide Residues in Wafer Fabrication Front-End Pre-Metal Layer Cleaning Process.

Salicide Residue is a common and well-known defect in CMOS technology of semiconductor wafer fabrication industries. This defect usually resides that is observed after Salicide Pre-Clean step whereby the product wafers after cleaning with standard diluted Hydrofluoric Acid (dHF). This defect can cause induced leakage current, directly impacting the electrical performance of the electronic product. Like many other wafer fabs, initiatives and efforts had been taken but never yield a very significant improvement. As of today, this type of defect is still persisting and remaining as one of the most challenging and unsolved phenomenon in wafer fabrication industry. This paper will explore next step towards eliminating the issues. Series of experiments were conducted to deduce the source to the root cause. Types of machines were screened through to dictate if the different machine hardware in general has significant contribution to the development of residue. Then the process tanks in the machine were tested to narrow the source of caused. The results of the experiments indicate a positive correlation between the DHF tank with the carbon residue after pre-salicidation clean which has lead the research to next step to solve the issue. [ABSTRACT FROM AUTHOR]