Figure 1-14.Vacuum evaporation oven.
The wafers, with appropriate masks (figure 1-15), are placed above and at some distance from the
material being evaporated. When the process is completed, the vacuum is released and the masks are
removed from the wafers. This process leaves a thin, uniform film of the deposition material on all parts
of the wafers exposed by the open portions of the mask. This process is also used to deposit
interconnections (leads) between components of an IC.
Figure 1-15.Evaporation mask.