| 摘要: | 本研究使用對稱型嵌段共聚物—聚苯乙烯-b-聚（甲基丙烯酸甲酯）混
摻與其分子量相當的聚苯乙烯均聚物（PS21k-b-PMMA21k/PS17k），在可形成穿
孔層結構之混摻比例下，以混摻溶液濃度與旋轉塗佈轉速控制薄膜初始厚
度，旋鍍薄膜沉積後將其在230 及270 ℃下進行1 小時及48 小時退火。並
透過光學顯微鏡（OM）、掃描式電子顯微鏡（SEM）、低掠角小角度X 光散
射儀（GISAXS）、X 光反射率（XRR）與中子反射（NR）對混摻薄膜進行
深入結構分析。
藉由臨場（in-situ）GISAXS 量測，在230 ℃退火1 小時內可觀察到緩
慢的動力學結構變化，且溫度降至室溫後仍未達平衡結構，而270 ℃退火
10 分鐘後結構不再變化而形成穩定結構。透過將GISAXS 影像中的截斷棒
進行定量分析結果，可以得知穿層間距約為37-40 nm，因此認為穿層間距
對於230 ℃與270 ℃的退火溫度並不敏感。若將GISAXS 進行q⊥方向的分
析可得出穿孔層結構主要以ABC 堆疊結構為主，透過angle-dependent
GISAXS 的分析可觀察到270 ℃退火的厚膜較230 ℃有序。XRR 與NR 則
可提供沿基材髮線方向的結構資訊。在薄膜中，XRR 曲線僅顯示高頻條紋
而無法看到與穿孔層相關的低頻條紋，這是由於在X 光下PS 與PMMA 之
間的SLD 對比度較低，而厚膜與此趨勢正好相反。對於PS-b-PMMA/dPS 的
混摻膜，NR 則顯示出兩種條紋，高頻條紋對應薄膜厚度，低頻條紋則與穿
孔層有關，低頻條紋的存在是由於dPS 與PS 相比具有高SLD 對比度。透
過XRR的定量分析與NR的模型擬合顯示出穿孔層的層間距約為27-32 nm。;We have demonstrated the phase behavior in blend films, which were prepared by blending a symmetric weakly-segregated, polystyrene-block-poly (methyl methacrylate), (PS-b-PMMA), block copolymer with a homopolystyrene of comparable molecular weight (hPS) at the volume ratio which can form perforated layer structure. Film thickness was controlled by the polymer concentrations and spin rates. After film deposition by spin coating, the films were annealed at 230 or 270 °C. The thin-film structures were investigated in depth by using optical microscopy (OM), scanning electron microscope (SEM), grazing-incidence small-angle X-ray scattering (GISAXS), grazing incidence X-ray reflectivity (XRR), and Neutron Reflectivity (NR).
It can be observed a slow kinetic structure changes within 1 hour of annealing at 230 °C by in-situ GISAXS measurement, and the equilibrium structure is not reached after the temperature drops to room temperature, while the structure no longer changes after annealing at 270 °C for 10 minutes. For GISAXS data, the quantitative analysis of truncation rods demonstrates that the inter-perforation distance was approximately 37~40 nm. The inter-perforation distance is insensitive to the annealing temperatures, 230 and 270 °C. The analysis of GISAXS in the q⊥ direction shows that the perforated layer structure is mainly an ABC stack structure. From the analysis of angle-dependent GISAXS, it can be observed that the thick film annealed at 270 °C is more ordered than that at 230 °C, while the thin film has a mixed structure of vertical and horizontal perforated layers. XRR and NR offer structural details along the normal direction of the substrate. For thin films, XRR curves only display high-frequency fringes, which correspond to film thickness. low-frequency fringes associated with inter-layer spacing are absent from the XRR curves. The absence of low-frequency fringes is due to low contrast in SLD between PS and PMMA under X-rays. For thick films, the trend is the opposite. The reason is that detecting the high-frequency fringes of thick films is beyond the instrument resolution. For PS-b-PMMA/dPS blend films, NR curves display two series of fringes. High-frequency fringes correspond to the film thickness and low-frequency fringes are associated with the perforated layers. The presence of the low-frequency fringes is because dPS has a high SLD contrast to the hydrogenated chains. Quantitative analysis of XRR spectra and model fitting of NR spectra demonstrate that the inter-layer spacing of perforated layers was approximately 27~32 nm. |
