Wet Process Defect Research

The wet cleaning is very important in the IC manufacturing process.This paper will introduce the concept and principle of wet cleaning,and focus on three kinds of defects,the photo resist residue,the abnormal oxide film thickness and the Scrubber V-type defect.For the photo resist residue defect,through analyzing the defect map and type,and combing with the recipe and the process of silicon infiltration theory to find out the defect sources is come for the HF tank,finally through adding the SC1 cleaning to solve the defect.It improves the yield about 1%.For the gate oxide thickness abnormal,combining with the wafer abnormal thickness position and the machine arm moving function,and then through doing experiment to find out the wafer be polluted by sulfur crystal which dropped from the moving arm.Finally,solve the problem by optimizing the arm operation mode and increasing the SPM processing time to 180 S.For the scrubber V type defect,combining with the characteristics of machine structure and cleaning function,and do a series of experiments to find out the reason is that the big size of oil particle be scattered by high pressure jet.Finally,solve the problem through making new cleaning SOP and changing the recipe from jet to spray in key stage.