Effect of Photo-active Compound Structure on Photosensitivity of Positive Photosensitive Polyimide

Abstract

The photo-active compound (PAC) in positive tone photosensitive polyimide (posi PSPI) was investigated in order to obtain good photo lithographic performance (small development loss and good photosensitivity). When the PAC structure was changed posi PSPI showed different levels of photosensitivity and development loss. The development loss and photosensitivity showed a good correlation. The lower development loss posi PSPI showed lower photosensitivity. From the molecular orbital calculation, the PAC in the lower development loss posi PSPI had a lower dipole moment than that in the larger development loss posi PSPI. In addition, dissolution rate measurement (DRM) results suggest that posi PSPI may have two layers from the point of dissolution. The dissolution rate of the surface layer in posi PSPI was shown to be lower than that of a bottom layer. This suggests that PAC using the lower development loss posi PSPI may exist mainly on its surface. These results are quite important for the design of good posi PSPI.

Recent Progress of Photosensitive Polyimides

“…It was noted that not only the polymer architecture but the structure of DNQ derivatives played important roles for better lithographic performance including sensitivity and pattern profile. 24 The photosensitive semi-alicyclic PHI with a low dielectric constant was reported by Jin and Ishii. 25 It was prepared from hydrogenated pyromellitic dianhydride and bis(o-amino phenol) (Table I, No.…”

“…They also blended an end-capped PAA to the poly(amic ethoxymethylester) described above to improve the mechanical properties of the PSPI film. 49 The PAA was incorporated with a siloxane moiety to improve the adhesion to Si wafers (Table I,No. 24).…”

A Computational Probe into the Dissolution Inhibitation Effect of Diazonaphthoquinone Photoactive Compounds on Positive Tone Photosensitive Polyimides

“…On the other hand, the protectable "skin layer" mechanism (Figure 1) was proposed according to some experimental studies on p-PSPI films using DNQ PACs with bisphenol or trisphenol backbones (Figure 2). 8,19 Two different dissolution rates between the surface and the bottom layers of these p-PSPI films were observed. This could be due to the fact that a high concentration of PAC is distributed on the film surface after prebake (PB).…”

“…In an effort to design PAA–DNQ type p -PSPIs with high contrast imaging, many approaches have been investigated. − These approaches can be divided into two aspects: modification of the PAA structures − and designing new PACs. − No matter which aspect was considered, it is inevitable to understand the interactions between PAA and PACs, and their dissolution inhibitation mechanisms for the design of good p -PSPIs. On the basis of the literature, two possible inhibitation mechanisms have been proposed for p -PSPIs, the novolac-type hydrogen-bonding mechanism and the so-called “skin layer” mechanism. − …”

The Photopolymer Science and Technology Award

“…In order to obtain high sensitive and precise pattering positive-tone-photo-definable polyimide, he examined the polarity of poly phenol compound of photo-reactive diazonaphthoquinone compounds [3]. He found that the diazonaphthoquinone compound composed of low polar polyphenol was tended to gather in the surface region.…”