A deposition member adapted for discharging a deposition material during a deposition
process can acquire a coating during the deposition. Such an initial emissivity
value is selected for the deposition member, before any of the coating became deposited,
that the emissivity of the deposition member remains substantially unchanged during
the deposition process. In a representative embodiment the deposition member is
coated with an appropriate thin layer for achieving the selected emissivity value.