Sub-10 Nm 2D Patterning Based On Self-assembly Of Hybrid Giant Molecules

The conventional photolithography nowadays has reached its physical limits—22 nm.Patterning method based on self-assembly of molecules has great promise in next-generation sub-10 nm patterning.In the early stage,most of the relative researches focused on block copolymers.However,due to their structural characteristics,block copolymers have insurmountable drawbacks in self-assembly and etching.Hybrid giant molecules are a kind of novel materials developed in recent years.They possess many advantages,such as extremely small feature size of assembled structures,rich phases and phase behavior,fast self-assembly dynamics,low line edge roughness,high etch selectivity,due to their unique and novel structures.Therefore,hybrid giant molecules have greater promise in next-generation nanopatterning than block copolymer.Herein,this subject utilized ATRP,click chemistry such as Cu AAC and TECC to synthesize hybrid giant molecules,such as DPOSS-PS consisting of?dihydroxy alkyl?-functionalized polyhedral oligomeric silsesquioxane DPOSS and polystyrene PS,FPOSS-PS consisting of?fluorinated alkyl?-functionalized polyhedral oligomeric silsesquioxane FPOSS and polystyrene PS and FPOSS-PMMA consisting of?fluorinated alkyl?-functionalized polyhedral oligomeric silsesquioxane FPOSS and poly?methyl methacrylate?PMMA,and studied their self-assembly results in thin films under solvent annealing and thermal annealing.The main research contents and conclusions are as follows.Firstly,when tetrahydrofuran was used as solvent for sample preparation,perpendicularly-oriented microdomains could be obtained for DPOSS-PS thin films.Through thermal annealing,thin films of DPOSS-PS could also form perpendicularly-oriented microdomains,but the structure was poorly ordered.By comparing the effect of toluene,tetrahydrofuran,chloroform and acetone in solvent annealing,it was found that they all could induce perpendicular microdomains,but the degree of ordering obtained in different solvents was acetone?chloroform>tetrahydrofuran>toluene.Through solvent annealing plus thermal annealing for about 3 min,highly ordered structures with very-low-density defects might be attained.By comparing,it was found that the self-assembly results of thin films of DPOSS-PS had no apparent relationship with annealing time and film thickness.CF₄:O₂=8:2 RIE could effectively etch DPOSS-PS thin films.Secondly,Thin films of FPOSS-PS_4.1k could not form perpendicularly-oriented structures through thermal annealing and solvent annealing in chloroform,while solvent annealing in ethyl acetate could induce perpendicular microdomains in some regions of the thin films.The area of the regions became larger with annealing time extended to some extent,but became smaller with annealing time further extended.Also,further thermal annealing for short time could induce similar effect.Thin films of FPOSS-PMMA_5.4k could not form perpendicularly-oriented microdomains by solvent annealing in toluene,tetrahydrofuran,chloroform and ethyl acetate.This work has proved that thin films of hybrid giant molecules might form perpendicularly-oriented structures with some degree of ordering by solvent annealing for about30 min and form highly ordered structures by further thermal annealing for less than 5 min.It does exhibit the great potential of hybrid giant molecules in patterning.