Characterization of Mano Scale PMMA Films Prepared by FDC Technique for FET Applications

摘要

Poly methyl methacrylate (PMMA) thin films were prepared by fast dip coating technique (FDCT). Benzene was used as a solvent to prepare PMMA films for various time periods ranging from 60 sec. to 1 hour. The thickness of the coated films were measured by using an electronic thickness measuring instrument (Tesatronic-TTD-20), gravimetric method and cross checked by optical spectrophotometer. FTIR spectrum was used to identify the above said coated films. XRD spectra of as grown and films annealed at various temperatures indicated the amorphous nature. Surface morphology of the coated films was studied by scanning electron microscope (SEM). No pits and pin holes were found in the surface. Both as grown and annealed films showed smooth and amorphous structure. C-V behavior of the MISM structures with Aluminum/PMMA/p-Si/Aluminum has been studied. C-V behavior for various bias voltage range of - 20 V to +20 V was provided. As grown films showed a flat band voltage (Vfb) shift towards the positive voltage where as annealed films showed a decrease in V_(FB )shift and it moved towards the zero flat band voltage (Vfb ~ 0) value. The observed surface morphology, C-V behavior and thermal stability indicated that these films could be used as effective dielectric layer in FET applications.