Films minces à base de Si nanostructuré pour des cellules ...

Figure 2.2: Illustration of sample fabrication methods.
tel-00916300, version 1 - 10 Dec 2013
Silicon Rich Silicon Oxide (SRSO)
Three dierent methods to introduce Si excess were employed for the fabrication of
SRSO.
Reactive magnetron sputtering: the SRSO layers were grown by sputtering
a pure SiO 2 target in a mixture of hydrogen and Ar plasma. The hydrogen-rich
plasma favors Si excess in the SiO 2 sublayer by the reduction reactions with oxygen
species [Gourbilleau 01]. The hydrogen gas rate, r H (%) was varied between 4.6-
57% in order to analyze the balance between deposition and etching. The RF power
density on the SiO 2 cathode was maintained at 7.4 W/cm 2 .
Magnetron co-sputtering: the SRSO layers were grown by simultaneously
sputtering the SiO 2 and Si targets in a pure Ar plasma. The RF power density on
SiO 2 cathode was xed at 7.4 W/cm 2 while that on Si cathode was varied between
1.62-2.96 W/cm 2 to analyze the eect of excess Si incorporation.
Reactive magnetron co-sputtering: this method is a combination of the
above mentioned methods. Both the targets, SiO 2 and Si were sputtered simultaneously
in hydrogen-rich plasma in order to witness an increase in the excess Si
incorporation obtained from the earlier used methods. The power of SiO 2 was xed
as before, and r H was xed at 26%, while the power density on the Si cathode was
varied between 1.62-2.96 W/cm 2 .
Silicon-rich silicon nitride (SiN x )
Two dierent approaches were used for the synthesis of silicon nitride as illustrated
in gure 2.2.
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