We measured the depth profile of hydrogen atoms in graphite by laser microprobing combined with resonant laser ablation. Deuterium-implanted graphite was employed for the measurements. The sample was ablated by a tunable laser with a wavelength corresponding to the resonant wavelength of 1<i>S</i>–2<i>S</i> of deuterium with two-photon excitation. The ablated deuterium was ionized by a 2 + 1 resonant ionization process. The ions were analyzed by a time-of-flight mass spectrometer. The deuterium ions were detected clearly with the resonant ablation. The detection limit was estimated to be less than 10<sup>16</sup> atoms/cm<sup>3</sup> in our experiments. We determined the depth profile by considering the etching profile and the etching rate. The depth profile agreed well with Monte Carlo simulations to within a precision of 23 μm for the center position and 4-μm precision for distributions for three different implantation depths.
© 2001 Optical Society of America
Masafumi Yorozu, Tatsuya Yanagida, Terunobu Nakajyo, Yasuhiro Okada, and Akira Endo, "Laser microprobe and resonant laser ablation for depth profile measurements of hydrogen isotope atoms contained in graphite," Appl. Opt. 40, 2043-2046 (2001)