Characterization of ion implanted silicon and diamond by variable wavelength photoacoustic microscopy and scanning acoustic microscopy.

An ion implanter of a 3 megaelectron-volt energy modifies a subsurface layer of crystalline silicon and diamond-like film. The thickness of layer is up to a few microns. A scanning acoustic microscope and a variable wavelength photoacoustic microscope reveal a change of elastic and thermal property of the layer. The crystalline silicon implanted with silicon ions at a 3 x 10¹⁷cm^-2dose shows a maximum 35% decrease of elasticity and a reduction of thermal conductivity by 3 orders of magnitude. The photoacoustic image of the diamond-like film implanted with nitrogen ions at a 7 x 10¹⁶cm^-2dose shows a variation of film quality.