Fluorescent lighting in chip factories creates tiny, possibly troublesome welts on the silicon used to make microcircuits, new experiments suggest.
Scientists who have seen such nanoscale bumps form in their lab say that light might be causing defects in the commercial chips most densely packed with transistors. Chips with such defects are probably among those discarded during production.
As future chips become denser still, it will become more critical to avoid roughened silicon surfaces, says Hitohi Morinaga of Tohoku University in Sendai, Japan. The bumps can cause current to leak or flow poorly.
Morinaga and his Tohoku colleagues Kenji Shimaoka and Tadhiro Ohmi report on light-induced silicon roughness, including surface pits, in the July Journal of the Electrochemical Society.