| 摘要 |
The present invention relates to an analytical method whereby a beam of ionised clusters is used to bombard a sample 70 under vacuum either as a secondary ion mass spectrometry (SIMS) analysis beam, or as a sputter or dosing beam during, or in rapid alternation with, bombardment by another beam that is acting as a SIMS analysis beam. The ionized clusters are formed from a gaseous mixture of a gas known to form clusters readily, e.g. helium, argon, neon, xenon, CO2 or nitrogen, and one or more hydrogen-rich hydrocarbons, such as methane, ethane, propane or butane. The gas mixture is expanded through a nozzle 10 and ionized by an electron bombardment source 20. This hydrocarbon-containing cluster ion source demonstrates higher yields of molecular secondary ions in comparison with established ion beams, thereby enhancing the chemical information obtained from the sample. |
