Measurement of Three Dimensional Distributions of Hydrogen in Thin Samples Using the 15 N Hydrogen Profiling Method

The use of the 15N+1H→12C+4He+γ-ray resonant nuclear reaction, with 4He particles recorded in plastic track detectors, is described as a method of measuring full three dimensional distributions of H in thin samples. To use this reaction to measure H concentrations, the sample is bombarded with 15N ions at an energy greater than the resonance energy at which the reaction occurs. As these ions penetrate the sample, they lose energy and reach the resonance energy at some depth. The yield of 4He particles from the reaction is proportional to the concentration of hydrogen at that depth. By recording the He particles in plastic track detectors, an autoradiograph of the lateral hydrogen distribution at the resonance depth is obtained. Limitations and potentials of this method are discussed along with some measurements of distributions of H ion implanted into silicon.