IMPACT OF ORGANIC CONTAMINATION ON THIN GATE OXIDE QUALITY

The impact of organic contamination on the quality of 5-nm-thick gate oxide structures, both before and after gate oxidation, is studied. So urces of organic contamination are chemical surface modification (i.e, hexamethyldisilazane priming), wafer box storage and extended vacuum exposure. Gate oxide integrity is evaluated electrically. The origin a nd/or nature of the organic contamination is seen to have different ef fects on the electrical breakdown. Care should be taken when exposing silicon wafers to organic contamination prior to processing. Especiall y when contamination occurs at the SiO2/polysilicon interface, i.e. pr ior to a non-oxidizing process step; organics can be extremely deleter ious.