2.1.2 Magnesium Oxide and Aluminum Oxide Surfaces

Different MgO based surfaces were tested to be used as the stop surface:

200nm MgO on graphite on Si substrate (`t4-200')
150nm Al $_{2}$ O $_{3}$ on 150nm MgO on graphite substrate (rough surface)
150nm MgO on 150nm Al $_{2}$ O $_{3}$ on graphite substrate (rough surface)
150nm Al $_{2}$ O $_{3}$ on graphite substrate (rough surface)
different MgO on graphite samples exposed to air for a prolonged time.

All these samples had a usable surface area of 1 to 2 cm $^{2}$ . The following surface was tested for use as a conversion surface:

MgO single crystal, (100) orientation, one side polished to the maximum extent possible (roughness < 5nm $_{rms}$ , 1nm typical)

This conversion surface had a size of 10mm x 10mm. The remaining surface roughness was typically of the order of 1nm $_{rms}$ as specified by the supplier [7].

March 2001 - Martin Wieser, Physikalisches Institut, University of Berne, Switzerland