makes it more difficult to determine if there were any changes. Similar results were

found for Samples 5 and 6. Sample 6 was the unetched sample and had an average star

height of 12.45nm. Sample 5 was etched in chlorine/argon plasma and had an average

star height of 12.25nm.

 The edge profile of the stars was also examined to determine if there was any

change after etching. Again, comparison of the unetched sample to the etched samples

showed no definitive difference in edge profiles between the samples. Figure 60 shows a

plot of the etched Samples 2 and 3 line scans superimposed over the unetched Sample 1

line scan. There is an area where it appears that there has been a build up or deposition at

the base of the star, possibly of gold chloride. There is also a loss of surface material on

the gallium arsenide substrate as noted by the negative area of the curve. This is an

indication that the gallium arsenide is being etched.


 Samples 1, 2, & 3
 c)
 18 > 2mTnrr
 16
 14
 12-
 10 Sample
 nm 8
 nm Sample
 4 Sample 3
 2 ;____________-----
 0
 -2
 -21 Y 2 3 4 5
 -4
 microns


Figure 60. This is a plot of the etched samples 2 and 3 line scans superimposed over the
unetched sample 1 line scan. There is an area where it appears that there has been a build
up or deposition at the base of the star, possibly of gold chloride. There is also a loss of
surface material on the gallium arsenide substrate as noted by the negative area of the
curve.