Chemical and Mechanical Analysis of HDIS Residues Using Auger Electron Spectroscopy and Nanoindentation

Abstract

Photoresist stripping after ion implantation at high dosages (>1E15 atoms/cm2) is the most challenging dry strip process for advanced logic devices. Such high-dose implant stripping (HDIS) frequently leaves residues on the wafers after dry strip, unless fluorine chemistries are employed in the stripping plasma. Silicon loss requirements at sub-45nm nodes generally preclude such aggressive stripping chemistries. Instead, a wet clean is used to remove residues. However, the nature of the residues is not well understood, and are believed to usually contain some of the cross-linked, carbonized organic polymer formed in the implant [1]. In this paper we present chemical and mechanical data on HDIS residues produced from oxidizing and reducing chemistry strip processes.