Moore’s law predicts that the areal density of transistors in semiconductor devices doubles every two years. The self-assembly of copolymers have emerged as a promising alternative to yield sub-10 features on Silicon substrates. In this work, we presented a solid-state hydrolysis strategy, where a hydrophobic-hydrophobic copolymer was hydrolyzed into a hydrophilic-hydrophobic copolymer in spin-coated thin films. The solid-state hydrolysis bypassed the poor solubility of high-chi copolymers. We introduced photoacid generators into the spin-coated copolymer films so that the solid-state hydrolysis can be achieved through exposure to UV light, aligning the self-assembly closer to currently used photolithography approaches in industry. To assist characterization of film thickness and X-ray scattering analysis, we developed an open-source Python package allowing X-ray scattering and specular reflectivity to be measured at the same areal detector. The orientation of the self-assembled patterns in thin films needs to be carefully controlled because only vertical orientation is suitable for pattern transfer into substrate through sequential etching. We developed a depth-sensitive characterization method using grazing-incidence small-angle neutron scattering. We identified that the horizontal patterns persist through the entire film while the vertical patterns only exist near the polymer-air and polymer-substrate interfaces and get randomized in depths away from the interfaces. Promoting vertical orientation of the self-assembled patterns is essential for pattern transfer. We developed block copolymers with low-surface-area junctions that assemble into vertical lamellae in spin-coated thin films. The self-assembly occurred on unmodified Silicon substrates without any surface modification or external field. Moving on from linear copolymers to bottlebrush copolymers, we first summarized recent progress on the architectural effect on polymer self-assembly in a review article. It is commonly believed that bottlebrush copolymers self-assemble more rapidly than their linear analogs due to the absence of entanglements. However, we found that high-chi bottlebrush copolymers are trapped in meta-stable poorly ordered status unlike their linear analogs, which evolve into better lateral order after thermal annealing. For low-chi bottlebrush copolymers, we highlighted the conformation of the molecular backbone in the self-assembled lamellar morphologies. Bottlebrush copolymers at lower grafting densities have the backbone looping back and forth between the two sidechain domains.