Figure 5

SEM images of fabricated sub-micron channels in silicon. (a) Top overview of a part of the main trench and the small growth channels. For illustration purposes we only show the small channels, but obtained similar results for the bigger growth channels. Here one clearly observes the control of the etching process as shown by the sharp boundaries of the structures. (b) Side view of a part of the main trench and the small growth channels. It is evident from this image that the etching resulted in the appropriate structures. (c,d) Zooming in on one of the small channels to illustrate its dimensions. The scalloping effect seen in (b) and (c) has to do with the repeating passivation and etching cycles of the Bosch process.