Fa. Stevie et al., Nanoscale elemental imaging of semiconductor materials using focused ion beam secondary ion mass spectrometry, J VAC SCI B, 17(6), 1999, pp. 2476-2482
The semiconductor industry demands elemental information from ever smaller
regions. The sensitivity of secondary ion mass spectrometry, coupled with t
he lateral resolution of a focused ion beam, can provide nanoscale elementa
l data that are competitive with that from other analytical techniques. Ion
images of the sidewalls in repetitive semiconductor features tilted to pre
sent a large surface area have shown boron contamination after an etch proc
ess. The boron is removed by a specific cleaning step. Spat defect analysis
was enhanced by the use of mass spectra that provide information on a rang
e of elements before the, defect is removed by sputtering. Ion implanted sa
mples were analyzed in cross section and the implant shape defected. Summat
ion of the secondary ion counts in the implant cross section over a few mic
rometers resulted in detection limits below 0.1 at. %. Implantation profile
s have been detected for Al, Cr, Na, Li, and K without the aid of secondary
ion enhancing species, such as oxygen or cesium. (C) 1999 American Vacuum
Society. [S0734-211X(99)04106-2].