An example apparatus for depositing a predetermined amount of a material onto a substrate includes a container having a cavity configured to contain the material. The container and the cavity are elongated along a first axis of the container. The apparatus further includes one or more heaters that are (i) elongated along the first axis and (ii) configured to heat and evaporate the material by heating the container. The apparatus further includes a conveyor for moving the substrate in a direction substantially perpendicular to the first axis of the container and one or more openings in the container distributed along the first axis. The one or more openings provide fluid communication between a region external to the container and the cavity. A process for depositing the predetermined amount of the material onto the substrate is also disclosed herein.