Stone wall model

Hanabata et al. have also shown that a narrow molecular weight distribution, particularly in the absence of low-molecular-weight fragments, is beneficial for good image resolution in DNQ/novolac resists. In addition, they proposed the so-called stone wall model of resist dissolution, where low-molecular-weight fragments (the small stones in the wall) can be dissolved out from the bulk of... 

M. Hanabata, Y. Uetani, and A. Furuta, Novolak design for high resolution positive photoresists. II. Stone wall model for positive photoresist development, Proc. SPIE 920, 43 (1988). 

Examples of models that have been proposed in an attempt to link the above steps into a coherent mechanism include the membrane model, the secondary structure model, the critical deprotonation model, the percolation model, the critical ionization model, and the stone wall model, to mention but a few. In the following sections, we briefly review the aspects of these models. 

Hanabata, Y. Uetani, and A. Furuta, Novolak design for high resolution positive photoresists. II. stone wall model for positive photoresist development, Proc. SPIE 920, 349 482 (1990). C.G. Willson, R. Miller, D. McKean, N. Clecak, T. Tompkins, D. Hofer, J. Michl, and J. Downing, Design of a positive resist for projection lithography in the mid UV, Polym. Sci. Eng. 23, 1004 (1983) M.K. Templeton, C.R. Szamanda, and A. Zampini, Dissolution kinetics of positive photo resists the secondary structure model, Proc. SPIE 771, 136 (1987). 

Figure 11.41 Stone wall model of DNQ/novolac resist development/...

Proposed by Hanabata et al. " in 1988, this model states that during development, the low-molecular-weight novolacs and sensitizer (referred to as the mortar of the wall) in the exposed part of DNQ/novolac resist dissolve quickly this has the effect of increasing the surface areas of the high-molecular-weight novolac (referred to as the stones of the wall) that is in contact with the developer, and will eventually lead to a breakup of the stone wall and result in dissolution (see Fig. 11.41). 

Modeling of Clamps and Dowels In ancient monuments, iron clamps and dowels exist between the beams of architraves and the stones of walls. In columns, iron dowels were rarely put at the joints, connecting adjacent drams. In such cases, these connectors must be included in the numerical models because they... 

For shear failure mechanisms of brick masonry walls, when mortar bed and head stone failure is involved, they proposed to adopt a Mohr-Coulomb friction model for the wall, namely ... 

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