ABSTRACT
Today, the predominant sources of defects lie within the wafer processing equipment. Defects introduced during individual process steps originate from particles generated by the process tool itself and/or by the process performed within the tool. The degree to which the hardware and the process can be fully integrated largely determines the defects that a specific process will contribute. In surveying levels of defects from the various unit processes throughout the integrated manufacturing process, one quickly realizes that each process can potentially contribute an alarming number of defects to device wafers. Some generic processes typically generate more defects than others; for example, chemical vapor deposition (CVD) processes are known to be significant particle generators because of flaking of large particles from thermally stressed films. Some of the important elements that determine the defect contribution from a process or process tool are: Design of equipment, Design of chemical processes, and Degree of maintenance.
