Developments in Ceramic Materials Research

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Li Chen
Figure 3. Vertical sidewall formed in SiO 2 cavity after anisotropy dry etching.
Figure 4. Clean back cathode contact revealed inside the SiO 2 cavity.
The ceramic samples were re-loaded back into the electron beam evaporation system.
When a base pressure and a specific elevated temperature of the system were reached, an
aluminium parting layer was deposited on the gate molybdenum layer. This was achieved by
rotating the sample holders at a slant angle with respect to the evaporation aluminium source,
while the aluminium evaporation process was taking place. The reasons for tilting the sample
holders and keep them rotating during the process are for the following purposes. First, it
prevents the aluminium evaporant from depositing onto the back contact electrode layer
through the cavity openings previously formed; second, it will produce smaller aluminium
apertures than the gate holes underneath, which is useful for the following metal lift-off