Towards the low-cost fabrication of a hard imprinting mold with micro-and nanostructures

a novel photocurable inorganic polymer was modified from perhydropolysilazane (PHPS) by grafting with 2-isocyanatoethyl methacrylate (ICMA) in this paper.The as-modified product was characterized by the methods of FTIR

1H-NMR

13C-NMR and 2D-1H-1H-NMR (COSY).The new peaks at =3.2~3.8 on1H-NMR spectra of the product were assigned to be the NHCH2 group

and =152~158 on 13C-NMR spectra was assigned to be the CONH group.In the FTIR spectra

the absorbing peaks at 2153 and 1363 cm-1(N=C=O)

1117 cm-1(CN C) of PHPS were obviously consumed after chemical modification

and the new peaks at 1690

1530 and 1314 cm-1(CONH)were appeared.Combined with the COSY analysis

it was concluded that the UV sensitive methacrylyate group was successfully grafted to PHPS

and methacrylated perhydropolysilazane (MPHPS) was used to name the as-modified product here.MPHPS was then used to fabricate the micro-and nanostructures via UV imprinting lithography using a fluoropolymer (FP) mold with microstructures

adding a pressure ranged in 0.1~0.4 MPa.The efficiency of the pattern transfer from FP mold was increased by the pressure increasing

and the thoroughly pattern copy was realized at 0.23 MPa.Besides

nanostructures with 90 nm

70 nm feature sizes were obtained at the pressure of 0.4 MPa.Then the as-prepared micro-and nanostructures were converted into SiO inorganic phase by a followed hydrolysis treatment.The converted product was concluded to be a composition of SiO1.5 from XPS depth profile.The final obtained mold was optical transparent

and with a hardness of 4.5103 MPa and a elastic modulus of 115103 MPa.