The evaporation process begins by placing material (usually pellets, wires, or granules) into a crucible. The heating element increases the temperature of the crucible, causing the material to sublime or evaporate. The evaporated material then travels along a line-of-sight path toward the substrate, where it condenses and forms a thin film. The substrate is carefully positioned to receive the evaporated material and can be rotated or tilted to ensure even deposition across its surface.
Thermal evaporation sources are widely used in various industries, including semiconductor manufacturing, optics, display technology and coatings. They offer simplicity, versatility, and the ability to deposit a wide range of materials, including metals, alloys, oxides, and organic compounds. The process can be easily controlled to achieve precise deposition rates, film thicknesses and compositions.
To increase the performance and efficiency of the thermal evaporation source, other functions can be combined. These may include shutter mechanisms to control the deposition process, ejection chambers to evaporate materials at lower temperatures, or thermal shields to minimize heat loss and improve temperature uniformity.
In summary, thermal evaporation sources are an important component of the physical vapor deposition process used to deposit thin films of materials onto substrates. They consist of a crucible or boat, a heating element and a temperature control system. Thermal evaporation is a common technology used in a variety of industries, allowing precise control of deposition rate, film thickness, and composition.
