Scanning Removal of Ion-implanted Novolak Resist by using a Laser Irradiation

Tomosumi Kamimura, Yuta Kuroki, Takuya Kiriyama, Hiroki Muraoka, Takashi Nishiyama, Toshiyuki Harada, Hiroyuki Kuramae, Hideo Horibe
2014 Journal of Photopolymer Science and Technology (Fotoporima Konwakai shi)  
Laser resist stripping for the ion-implanted novolak resist was successfully performed without occurring laser damage to the Si wafer. In order for the advanced laser resist stripping method to be successful, it is important for the pulsed laser beam to pass though the ion-implanted resist and absorb into the Si wafer surface. The novolak resists which are implanted with B, P, and As ions, respectively, were irradiated with a pulsed 532nm laser. Regardless of the implanted ion species and
more » ... n species and density, more than 74 % of the laser power was found to absorb into the Si wafer surface. For the laser irradiation of 1 pulse, the ion-implanted resist with a density of 5.0×10 13 atoms/cm 2 was completely stripped in the same way as that of a non-implanted resist. The optical absorption of the resist surface increased as the density of the ion-implantation increased. In case of the ion-implanted resist with a density of 5.0×10 15 atoms/cm 2 , the resist was stripped by 20 pulses irradiation without occurring laser-induced surface damage. A scanning removal of the highly ion-implanted resist was also successfully stripped by using an optimized irradiation condition. A highly ion-implanted resist was continuously stripped by the scanning laser irradiation with 20 pulses.
doi:10.2494/photopolymer.27.237 fatcat:pzn7gttk2jakfhwqbjoviwbrtq