Removal of Novolac Photoresist with Various Concentrations of Photo-active Compound Using H&lt;sub&gt;2&lt;/sub&gt;/O&lt;sub&gt;2&lt;/sub&gt; Mixtures Activated on a Tungsten Hot-wire Catalyst

Akita, Koki; Sogo, Shota; Sogame, Ryusei; Yamamoto, Masashi; Nagaoka, Shiro; Umemoto, Hironobu; Horibe, Hideo

doi:10.2494/photopolymer.34.499

Cited by 1 publication

(6 citation statements)

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“…4(a), exhibiting the case of only the polymer, the removal rate for either polymer was almost constant even if the added oxygen amount was increased. This tendency resembles that in the case in which only novolac resin was used [4]. When the PAC content was 9.4 wt%, a difference in removal rates between polymers was found for the added oxygen amount of 0.5 sccm.…”

Section: Resultssupporting

confidence: 69%

“…The apparatus and the procedure used for experimentation were similar to those described elsewhere [1][2][3][4]. The H2 gas (≥99.99%; Takamatsu Teisan) flow rate was fixed at 100 sccm using a mass flow controller.…”

Section: Removal Rate Examinationmentioning

confidence: 99%

“…Changes in film thickness were evaluated using thin film interference of the photoresist [1][2][3][4]. By thin film interference, the peaks and valleys of the reflected light intensity were observed alternately during changes in film thickness.…”

Section: Removal Rate Examinationmentioning

confidence: 99%

“…The environmental burdens and costs caused by harmful chemicals used for photoresist removal processes during conventional semiconductor manufacturing are regarded as important shortcomings. To overcome these difficulties, we have studied an "environmentally friendly" photoresist removal method using radicals generated by activating H2/O2 mixed gas on a hot filament surface [1][2][3][4]. This method allows oxidizing O radicals and OH radicals to coexist in a reducing H radical atmosphere [5][6][7].…”

Section: Introductionmentioning

confidence: 99%

“…In our recent study, we used activated H2/O2 mixed gas to examine the removal rate of pseudophotoresists, which comprise novolac resin with various contents of photoactive compound (PAC) [4]. Results show that the decrease in the removal rate which occurred for a given excess added oxygen amount varied with the PAC content.…”

Section: Introductionmentioning

confidence: 99%

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Photoactive Compounds Effects on Removal Rate for Polystyrene-type Polymers by H2/O2 Mixture Activated by Hot Tungsten Wire

Yamamoto,

Akita,

Maniwa

et al. 2023

J. Photopol. Sci. Technol.

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We earlier reported that the removal rate of positive-tone novolac photoresist was enhanced compared to that of a pure hydrogen system when a H2/O2 gas mixture is activated by a hot tungsten filament. However, when the added oxygen amount was increased to more than 1.0%, the removal rate decreased considerably. We specifically examined cross-linking between novolac resin and photoactive compound (PAC), which are the main photoresist components, as one cause of this decrease in the removal rate. For examination in this study, the "PAC-mediated cross-linking model" was proposed to identify the cross-linking site on novolac resin. To investigate functional group interaction with PAC, we examined the removability of polystyrene-based polymers with various PAC contents. For poly(vinyl phenol), which has an OH group at the terminal end on side chain, a markedly decreased removal rate was confirmed with increased added oxygen when the PAC content was 18.7 wt%. This decrease was never observed in others. For the commercial positive-tone novolac photoresist, the decreased removal rate under excessive oxygen addition might be ascribed to cross-linking, which can be formed by mediating PACs near OH groups on the main chain of novolac resin.

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Section: Resultssupporting

confidence: 69%