Time-of-flight mass spectrometry depth profiling of sodium-implanted polyethylene terephthalate

Depth profiling analysis of sodium (Na)-implanted polyethylene terephthalate was performed by using time-of-flight secondary ion mass spectrometry in the cesium-attachment regime. A radical redistribution of the main element due to diffusion and escape of some elements, such as oxygen and hydrogen, and carbonization of a top 550nm layer were observed. The depth distribution of the implanted sodium was found to be radically different from the theoretical distribution calculated by using the Monte Carlo simulation method (TRIM code). We conclude that it is possible to perform an effective depth profiling analysis of an implanted polymer in the standard secondary ion mass spectrometry regime without using a big cluster primary ion beam.