948708.fig.008a
(a) Near wafer center
948708.fig.008b
(b) Near wafer edge
948708.fig.008c
(c) Near wafer center
948708.fig.008d
(d) Near wafer edge
Figure 8: SEM images of the emitters after RIE of Si at different etching parameters: (a) and (b) 90 mTorr, 60 s, 90 W, (c) and (d) 50 mTorr, 90 s, 90 W.