Lab news: SEM of ice crystals
We tested a new substrate in the ice crystal project: A silicon wafer with microscale markers ("+", "5"). Ice crystals are a bit picky: They require very clean oxidized wafers to grow, which is a challenge especially in presence of markers. The markers contain metals (Au, Pd), but were produced by electron beam lithography of polymer layers. The hexagonal ice crystal has ca. 55 micron diameter. Growth and imaging conditions: 2.09 mbar water vapour, -14.9ºC substrate temperature, 10 kV electron beam acceleration voltage, environmental SEM, i.e. detection of an ionisation cascade in water vapour.