Is I/sub DDQ/ yield loss inevitable?

I/sub DDQ/ testing is a powerful way to improve the quality of low fault coverage tests, and to detect defects that are hard or impossible to detect using traditional voltage testing methods. However, it appears that there is some yield loss associated with I/sub DDQ/ testing, where yield loss means that devices passing burn-in and system tests fail I/sub DDQ/ test. This paper gives reasons why such yield loss is inevitable, and must be considered when making a decision whether or not to use I/sub DDQ/ testing. We also present some evidence backing up this speculation, and a brief economic model to help in making I/sub DDQ/ testing decisions.