Residue formation in the removal of ion implanted photoresist

The phenomenon of residue formation after the stripping process of ion impl anted photoresist and the dependence of the residue formation on ion source and dose level have been investigated. To analyze residues, several surfac e analysis tools have been used. Implant of Ar+, BF2+, and P+ and several k inds of dose levels have been used for ion implantation on photoresist mask ed samples. It was found that the formation of residues strongly depends on ion source and dose level. Residues have been detected only in the case of phosphorus ion at the dose of 6E15 ions/cm(2) and above, where phosphorus ion can be reacted with oxygen and easily form phosphorus oxide. AES analys is of residues show that the surface of residue is covered with PxOy/hydroc arbon composition layer. The results indicate that if implanted ion source produce inorganic compounds through the reaction with oxygen radical, it is difficult to remove the residues completely with normal PR stripping proce ss.