摘要(英) |
Gallium oxide (Ga2O3) is a new material of oxide semiconductor . For
the wide Band-gap material property , Gallium oxide has the potential to
develop as efficient electro components. Compare with growing from the gas
phase, β-Ga2O3 crystals could be grown from liquid phase and also have
higher growth rate as well as better quality. The temperature field of the cavity
and the melt flow affect the crystal-melt interface shape and energy balance .
And also the crystal-melt interface shape will affect the stability of crystal
formation during crystal growth . Therefore the control of the crystal growth
temperature field and melt convection is very important .
This study analyzes the crystal-melt interface shape and position when
the Ga2O3 crystal grows in Czochralski method through numerical
simulation . In the simulation , we change coils spacing and position of
induction heating coil and also the input power to see the difference in the
result . Last, according to the heat flux difference , on the crystal-melt
interface , to adjust the interface geometric position till convergence .
The results show that the temperature field and flow field in the crystal
growth furnace will affect the energy balance on the crystal-melt interface .
Under the condition of fixed crystal pulling speed , the spacing and position
of heating coils will cause different degrees of unevenness of the interface .
Based on reference reviews , the interface convex to the melt is easier to grow
complete crystals . Known from the simulation result , the flow field pattern
in the melt is dominated by buoyant force, and the isotherm line is deformed
by convection. In order to reach the energy balance on the crystal-melt
interface, when the input power increases, the shape of the interface will
change towards the crystal direction.
IV
In addition, when the power is too high, the interface shape will change
from convex to concave . The second result is that the higher the coil position,
the higher the convexity of the interface in the melt . Furthermore, increasing
the position of the coil will increase the axial variation of the crystal-melt
interface. Third result is the expansion of coil spacing , which will lower the
temperature of the melt and cause the interface to increase the convexity in
the melt . When the coil spacing is too large, the melt temperature will be
lower than the melting point temperature. |
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