Crystal orientation effects on sputtering and depth resolution in GDOES

We investigate crystal orientation effects in the sputtering rate of pure iron in glow discharge optical emission spectrometry (GDOES). Scanning electron microscopy (SEM), optical profilometry and electron backscattered diffraction (EBSD) are used to investigate details of the surface structure and to correlate the depth of burn—and hence sputtering rate—with the crystallography of the sample. The microstructure of the sputtered crater bottom is classified into three types: ‘rough’, ‘concaved’ and ‘smooth’. It was found that there is a correlation between the crystal orientation normal to the surface, the resulting surface texture and the sputtering rate: ‘rough’ texture results from a crystallographic pole of [111] normal to the surface; ‘concaved’ texture is close to [001]; and ‘smooth’ tends to be between [111] and [001]. It was found that the average sputtered depth of the micro‐areas close to [001] pole is deeper than that of those close to [111]. Implications for the depth resolution in GDOES are discussed. Copyright © 2001 John Wiley & Sons, Ltd.