Matrix effects on dopant positive secondary ion yields for the InGaAs/InP material system measured in various secondary ion mass spectrometers.

Matrix effects on the positive secondary ion yields of a number of common dopants from InGaAs relative to InP under O sub 2 sup + primary ion bombardment have been measured in three different types of secondary ion mass spectrometer. Two of these were ion microprobe systems with quadrupole mass spectrometers, one employing a very low secondary ion collection field (~1 Vcm sup (-1)) and the other a more substantial field (30-80 Vcm sup (-1)). Both of these instruments generally employed the primary ion beam at normal incidence to the sample, although this was varied in one instrument. The third instrument was an ion microscope with an off-normal incident beam and strong secondary ion extraction field (10 sup 4 Vcm sup (-1)). Secondary ion yields from InGaAs were up to an order of magnitude greater than from InP in both quadrupole systems, with the magnitude of the matrix effect increasing with the first ionization potential.