Field-induced surface passivation of p-type silicon by using AlON films

In the present work, we report on the evidence for a high negative charge density in aluminum oxinitride (AlON) coating on silicon. A comparative study was carried out on the composition and electrical properties of AlON and aluminum nitride (AlN). AlON films were deposited on p-type Si (1 0 0) substrate by RF magnetron sputtering using a mixture of argon and oxygen gases at substrate temperature of 300 degrees C. The electrical properties of the AlON, AlN films were studied through capacitance-voltage (C-P) characteristics of metal-insulator semiconductor (MIS) using the films as insulating layers. The flatband voltage shift V-FB observed for AlON is around 4.5 V, which is high as compared to the AlN thin film. Heat treatment caused the V-FB reduction to 3 V, but still the negative charge density was observed to be very high. In the AlN film, no fixed negative charge was observed at all. The XRD spectrum of AlON shows the major peaks of AlON (2 2 0) and AlN (0 0 2), located at 20 value of 32.96 degrees and 37.8 degrees, respectively. The atomic percentage of Al, N in AlN film was found to be 42.5% and 57.5%, respectively. Atomic percentages of Al, N and O in EDS of AlON film are 20.21%, 27.31% and 52.48%, respectively. (c) 2007 Elsevier Ltd. All rights reserved

Fabrication of needle-like nanostructures using block copolymer for non-volatile memory

In this work, the fabrication of nanostructures applicable to nano floating gate memory is investigated by using a block co-polymer system composed of Polystyrene (PS) and Polymethylmethacrylate (PMMA). A thin film of self-assembled block copolymer has been used during all experiments for nanostructures with critical dimensions below photolithographic resolution limits. Under suitable conditions, the PS and PMMA self assembled into a honey comb lattice of PMMA in the matrix of PS. Nanoporous thin film from PS-b-PMMA diblock co-polymer thin film with selective removal of PMMA domains was used to fabricate needle-like nanostructures. The reactive ion etching (RIE) was then carried out at room temperature in a single wafer RIE system with the substrate having nano-cylindrical structures. The plasma was excited by radio frequency. Diverse surface nanostructures of sub-100 nm patterning were fabricated by plasma etching using block co-polymer. Finally, we have demonstrated that by combining these self assembled block co-polyrners with regular semiconductor processing, a non-volatile memory device with increased charge storage capacity over planar structures can be realized. (C) 2006 Elsevier B.V. All rights reserved.X118sciescopu

Fabrication of nanostructure and formation of nanocrystal for non-volatile memory

In this work, we have demonstrated that the nanocrystal created by combining the self-assembled block copolymer thin film with regular semiconductor processing can be applicable to non-volatile memory device with increased charge storage capacity over planar structures. Self-assembled block copolymer thin film for nanostructures with critical dimensions below photolithographic resolution limits has been used during all experiments. Nanoporous thin film from PS-b-PMMA diblock copolymer thin film with selective removal of PMMA domains was used to fabricate nanostructure and nanocrystal. We have also reported about surface morphologies and electrical properties of the nano-needle structure formed by RIE technique. The details of nanoscale pattern of the very uniform arrays using RIE are presented. We fabricated different surface structure of nanoscale using block copolymer. We also deposited Si-rich SiNx layer using ICP-CVD on the silicon surface of nanostructure. The deposited films were studied after annealing. PL studies demonstrated nanocrystal in Si-rich SiNx film on nanostructure of silicon.X113sciescopu