Multiple Scattering Effects of Ag Particles in Random Ag--SiN film

A layer of 40nm-thick Ag--SiN film with Ag nano-particles embedded and distributed randomly in the SiN thin film were deposited by the method of radiant-frequency magnetron sputtering. Specimens orderly comprising a random Ag--SiN film and an optical phase change recording layer were exposed to a focused laser beam with wavelength of 690nm. It is shown that, with a random Ag--SiN layer deposited above the recording layer. Calculation by the finite difference time domain method of a 40nm-thick SiN film under a Gaussian beam irradiation has been carried out to simulate the near-field distribution in the film, which showed a huge local near-field intensity enhancement of about 200 times if small Ag particles with diameter of 6nm were modelled in the SiN film in the central region of the incident laser spot.