Resist trimming using a CF 4 /O 2 plasma generated by an inductively coupled high-density plasma source is investigated. Results show that the resist trimming process is applicable for the fabrication of a sub-0.1 m polysilicon gate electrode with conventional 248 nm lithography. The trim rate depends strongly on gas composition, temperature, rf source power, bias voltage, reactor pressure and total gas flow. The trim rate increases with increasing temperature, rf source power and reactor pressure but decreases with higher bias voltage. For a typical trimming condition at gas composition of CF 4 and O 2 with a ratio of 3.3:1, the resist trim rates are 1.0 and 1.2 nm/s for dense and isolated lines, respectively. By examining the effect of various process parameters, it is found that the trimming process is dominated by the neutral reactant species. Angle-resolved x-ray photoelectron spectroscopy shows that a fluorinated carbon oxyfluoride polymer is deposited on the sidewall of photoresist. The degree of carbon fluorination of the film is influenced by the process parameters. A more fluorinated film, obtained at lower bias voltage and higher source power, gives more trimming.
A multi-image encryption scheme based on the fractional-order hyperchaotic system is designed in this paper. The chaotic characteristics of this system are analyzed by the phase diagram, Lyapunov exponent and bifurcation diagram. According to the analyses results, an interesting image encryption algorithm is proposed. Multiple grayscale images are fused into a color image using different channels. Then, the color image is scrambled and diffused in order to obtain a more secure cipher image. The pixel confusion operation and diffusion operation are assisted by fractional hyperchaotic system. Experimental simulation and test results indicate that the devised multi-image encryption scheme can effectively encrypt multiple images, which increase the efficiency of image encryption and transmission, and have good security performance.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.