Prioritizing efforts to improve semiconductor production yield

A method of identifying causes which reduce the yield of a manufacturing process, said process producing wafers containing semiconductor circuitry and involving multiple processing steps including a first specific process step which potentially introduces particulate deposits on wafers, comprising the steps of:

• detecting a number and location of particulate deposits on a wafer prior to and subsequent to said first specific process step, and determining therefrom a number and locations of particulate deposits introduced during said first specific process step;
• electrically testing semiconductor circuitry in a plurality of locations of said wafer subsequent to said first specific process step, and identifying locations of said wafer which contain faulty circuitry;
• correlating the locations of particulate deposits introduced during said first specific process step to the locations of said wafer containing faulty circuitry subsequent to said first specific process step, said correlating comprising computing a first yield rate for locations containing a detected particle, by computing a ratio of a number of tested locations that contained a particle and were not faulty, to a number of tested locations that contained a particle, and computing a second yield rate for locations not containing a detected particle, by computing a ratio of a number of tested locations that did not contain a particle and were not faulty, to a number of tested locations that did not contain a particle;
• and
• determining, from said correlating, a first measure of the extent to which particulate deposits introduced during said first specific process step contribute to reductions in yield of said manufacturing process.