Vacuum ultraviolet smoothing of nanometer-scale asperities of Poly(methyl methacrylate) surface

Abstract

Smoothing of the nanometerscale asperities of a poly(methyl methacrylate) (PMMA) film using vacuum ultraviolet (VUV) with the wavelength λ = 123.6 nm was studied. The exposure time and the residual air pressure in a working chamber were varied during the process of VUV treatment. A nanostructured sur� face of PMMA film is used as a sample to be exposed. The nanostructured surface of the PMMA film was obtained by treating the initially smooth spincoated film in oxygen radiofrequency plasma. The degree of VUV exposure is estimated using changes in the morphology and roughness of the nanostructured surface, which were determined by atomicforce microscopy (AFM). Recognition of morphological surface features on the AFMimages and determination of main geometri cal characteristics of these features are performed by using virtual featureoriented scanning method. It is discovered by morphology and Fourier spectra that the nanostructured surface of the PMMA film is partially ordered. The developed VUV smoothing procedure can be used to treat the electronb eam, UV, and Xray sensitive PMMA resists, PMMA elements of micro� electromechanical systems, biomedical PMMA implants, as well as to certify nanotechnological equipment incorporating UV radiation sources. DOI: 10.1134/S1027451010010015