Dear all members,

According to me.

•To deposit coatings in the vacuum evaporation, the deposit should follow a specified thickness distribution over the substrate surface, i.e. it may need to be uniform on plane or curved surfaces.

•To obtain the specified film distribution one has to consider • The shape of the receiving surface and the arrangement of the vapour source or sources relative to the surface.

• Mode of evaporation from the source in

1) uniformly in all directions

2) Preferred directions

The supporting theory in general assumed that the evaporation takes place according to Knudsen's cosine law.

Any more suggestions