Investigation on surface contamination caused by human on phase shifter chip

As semiconductor industry strives to keep pace with the rapidly shrinking feature size and ever-smaller chip size, surface sensitivity has increased gradually especially on micro-chips. Stronger emphasis must be placed on chip contamination to achieve higher reliability. Phase shifter chip employed in this paper was contaminated on the surface. By combining scanning electron microscopy and X-Ray spectroscopy, microstructure and micro-area composition of contaminants were thoroughly analyzed. The results revealed that the pollutants were mainly salt and organic compound. In order to further determine the salt source, comparative simulated trial on clean wafer was also conducted. It confirmed that the contamination was caused by human body fluid due to the participation of human in the processing of chips. On the basis of that, the corresponding improvement measures have been proposed to greatly suppress the similar contamination.