Secondary ion mass spectrometry system and method for focused ion beam with parallel ion detection

A secondary ion mass spectrometry system for rapidly and comprehensively detecting and categorizing the secondary ions produced by a focused ion beam striking a target, comprising:

• a mass separator for spatially separating the secondary ions in accordance with their respective masses,
• a sensor array adapted to simultaneously sense the presence of mass separated secondary ions at intervals corresponding to mass separations no greater than about one atomic mass unit per interval within a predetermined range of ion masses, said sensor array comprising an array of spatially discrete charge collectors, said charge collectors corresponding to respective secondary ion masses at said intervals and positioned to sense the presence of secondary ions of said respective masses, and
• a decoding means responsive to the sensor array for determining the masses of the secondary ions sensed by the array as a function of the location of the mass separated seconary ions, said decoding means comprising a plurality of output lines which are fewer in number than the number of charge collectors, and circuit means coupling each charge collector to a unique set of output lines, whereby a unique set of outputs is produced over said output lines for each different mass of secondary ion sensed by the sensor array,
• the decoding means having a responsivity which is faster than the anticipated time interval between the arrival of successive secondary ions.