本研究在探討非對稱型團鏈高分子P(S-b-MMA)薄膜分別利用旋轉塗佈旋鍍在SiOx/Si、PMMA-SiOx/Si、以及PS-SiOx/Si基材上，除潤現象對微米尺度結構、原子尺度的粗糙度、以及分子尺度的奈米結構排整的影響。在極性基材上由於初始旋鍍膜厚不符合相稱厚度，在回火程序中膜厚產生擾動而形成非潤溼結構，用以滿足膜厚相稱性。在低掠角小角度X光(GISAXS)二維散射圖譜中，發現與垂直方向夾角約6o的位置有源自浮凸結構的散射條紋。這些浮凸結構是由於不受基材錨定的P(S-b-MMA)與下方潤溼層彼此間因自我除潤效應而產生除潤，接觸角約4-6.5o且擁有似結晶的琢面。非潤溼結構是除了經由成核與成長機制而形成，且會影響奈米微結構的排整和排向行為。此外、初期除潤過程中，當包埋在膜內的有序奈米結構形成後，增加了結構的形變能量，使得微米潤溼浮凸結構邊緣似結晶琢面。然而這些浮凸結構仍不是處在平衡的狀態，所以當回火溫度提高時，微米尺寸結構會轉變為液滴形貌，且在圓弧表面伴隨著奈米結構由柱狀相轉為圓球狀奈米結構。相較之下，對於滿足對稱型潤溼邊界的PS-SiOx/Si基材，因初始厚度接近於相稱厚度，回火程序中便會以鏈段拉伸取代膜厚擾動，導致薄膜自由表面粗糙且晶粒較小。 The present work focuses on the effects of film instability on micro-scale structure, surface roughness and ordering of cylindrical nanodomain in P(S-b-MMA) ultrathin block copolymer film on bare silicon substrates (SiOx/Si) and substrates coated with end-grafting PMMA (PMMA-SiOx/Si) and PS (PS-SiOx/Si) homopolymers. If the initial film thickness of thin films was incommensurated with an intracylindrical spacing, thermal annealing lead to relief structures with smooth free surface so as to achieve the commensurability of film thickness with the intracylindrical spacing. The diffuse scattering streaks were observed at angles with respect to film normal direaction in GISAXS patterns, and the diffuse streaks were found to correlated with the formation of relief structures. The relief structures have a facet-like wedge at the edge, resulting from partial wetting of the non-anchored P(S-b-MMA) top layer at contact angle in the range 4-6.5o on a autophobic P(S-b-MMA) wetting layer anchored onto the polar substrate. As a result, the dewetted morphologies via a mechanism of nucleation and growth strongly influences the spatial and ordering behavior of the nanodomains. At early stages of film instability, the formation of parallel-oriented PMMA cylindrical nanodomains increases the deformation energy and it further persists to force the shape of relief structures between irregular holes to have a facet-wedge shape. However, those relief structures are expected to be not at equilibrium. At high temperatures, the relief structures between irregular holes progressively developed to form drops accompanied by a transformation of cylindrical into noncylindrical nanodomains at curved surfaces. In contrast, for symmetric wetting boundaries on PS-SiOx/Si, thin film that resisted dewetting on a PS brush have a rough free surface due to the film commensurability. In the absence of undulations in thickness, a perturbation, as result of chain stretching, in the inter-domain spacing yielded small in-plane randomly oriented monograins on PS-SiOx/Si. Consequently, the free surface roughening was allowable to occur due to preferential segregation of excluded polymer chains from monograin boundaries onto the free surface.
