Photoresist properties during high current implantation: an I-line vs. DUV resist comparison

As of recently, certain critical processes have required the migration from I-line to DUV photoresist to address scaling device trends. DUV resist advantages are essential to critical dry etch and photolithography processes by providing improved resolution and CD control, as well as, precise layer to layer photo alignment. Although the ion implantation process itself does not require a DUV resist mask layer, it is typically incorporated to accommodate a subsequent critical etch process. Therefore, it is necessary to evaluate all factors and risks which may compromise DUV resist properties during implantation, or adversely affect the implantation process itself. A comprehensive comparison of DUV vs. I-line resist was performed using a typical production high current/high dose implant application approach. The resist properties under evaluation included the effects of photostabilization, resist stability, edge profile integrity, resist shrinking effects, resist outgassing, implant dosimetry, and particle generation. Each of the above resist properties were carefully examined, and a side by side analysis was performed. The comparative analysis data will show that DUV resist successfully withstood the implant challenges, and its resist properties were equivalent to I-line resist when exposed to high current/high dose ion implant applications.