Removal Technology of Poly-Vinyl Phenol Using Laser Irradiation

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Laser induced resist stripping technique in water is interesting for both fast and environment-friendly resist removal. However, small pieces of the deposited resist still remain or reattach on the silicon (Si) wafer after laser irradiation. In order to eliminate the remaining resist on the Si wafer surface in environment-friendly way, the effects of ozone water and ozone microbubble water treatments were investigated. The laser induced resist stripping area was effectively expanded by 1.27 times in 600 sec by the immersion treatment in ozone water. Furthermore, combination of ozone microbubbles and flowing water treatment enhanced the resist removal rate by about 20% each. These results demonstrated that the synergy of the laser induced effect, the ozone microbubble and flowing water treatment has a great potential for fast and environment-friendly resist removal technique.

“…First, the laser induced damage threshold of the Si wafer is higher in water than in normal atmosphere conditions, and the risk of the laser induced damage on the Si surface is lower [6].…”

Section: Introductionmentioning

confidence: 99%

Resist Removal Using Laser Irradiation Combined with Ozone Water Treatment

Yasukuni,

Koizumi,

Mizutani

et al. 2023

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“…And, irradiation with multiple laser beams with a small beam diameter was confirmed as one of the methods for improvement of a resist stripping rate with high efficiency [17]. Poly(4-vinylphenol) (PVP) used as a base polymer of the KrF resist was also removed by laser irradiation in the water [18].…”

Section: Introductionmentioning

confidence: 99%

Time-resolved Analysis of Resist Stripping Phenomenon Using Laser Irradiation

Kamimura

Umeda

Kuramae

et al. 2018

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Resist stripping phenomenon with laser irradiation was observed by using a time-resolved analysis. The time change of the resist stripping phenomenon by a probe laser irradiation was observed from the viewpoint of the intensity change of the probe laser. As for the laser irradiation in the water, the probe laser intensity arrived at the maximum after around 40 μs. During the pump laser irradiation of 8 ns, a large compressive stress of -10 MPa was confirmed inside the resist from the FE analysis results. The generation of this compression stress is important for starting the resist stripping process, and is thought to improve the resist removal efficiency.

“…And, irradiation with multiple laser beams by small beam diameter was confirmed as one of the methods for improvement of a resist stripping rate with high efficiency [17]. Poly-Vinyl Phenol (PVP) used as a base polymer of the KrF resist was also removed by laser irradiation in the water [18].…”

Section: Introductionmentioning

confidence: 99%

Analysis of Resist Removal Phenomenon Using Laser Irradiation

Kamimura

Kuramae

Yamashiro

et al. 2017

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Resist removal phenomenon with laser irradiation was analyzed by using a finite element (FE) method. Laser irradiation in the water can improve the resist removal effect as compared with that of normal atmosphere irradiation. A two-dimensional (2-D) micro-FE model was constructed based on the boundary surface between the Si wafer, resist and water during laser radiation. In the normal atmosphere, any effective stress did not occur along the x-axis direction in the resist. In contrast, for the laser irradiation in the water, large compressive stress was confirmed along the x-axis direction in the resist. This compressive stress in the resist is thought to improve the resist removal efficiency.