A thin film substrate is a layer of material applied with thin film technology. Many industrial and technological devices require coating with a thin layer of a particular chemical or substance. Thin film, a technology created in the late 20th century, allows the creation of layers of microscopic thickness, sometimes as thin as the width of a single atom. This is useful for materials that are too expensive to use in large quantities, such as some semiconductors. In most cases, a thin film substrate is just one part of a much more complex design.
A substrate is simply a surface for attaching a layer of material of varying thickness. A common example is paint primer, which coats an object, such as an auto body part, so that further layers of paint will adhere more readily. Substrates appear in a multitude of manufactured and natural objects. Thin film substrate extends this concept to a level that is only possible using a high degree of technology. Such substrates can be applied with a variety of chemical or technological processes.
Thin film substrate has many uses in modern technology. For example, semiconducting materials such as gallium arsenide can control the flow of electricity in a way that makes them invaluable for miniaturized circuit boards. This material is expensive to produce; fortunately, it can work even if a small quantity is present. Thin-film technology allows a minimum of the substance to be spread evenly over a surface with no gaps, maximizing its efficiency. This substrate can then be attached to more inexpensive materials to create a functioning semiconductor.
There are various methods to create a thin film substrate. Some are chemical processes, such as the method used to create thin film solar cells. The substance is reduced to a liquid and then sprayed on a positively charged plate so that it adheres in a thin, evenly distributed layer. Other methods use physical manufacturing processes, such as creating stacks of thin film substrate between wafers of other material. The other material is then dissolved or removed, leaving a layer of thin film that can be applied elsewhere.
There are many uses for this material. Thin film can be used in solar cells, computer hardware, and batteries to make the most efficient use of expensive materials. Thin film coating on an optical lens can protect the lens or alter the way it processes light. Thin film drug delivery uses the technology to distribute tiny quantities of therapeutic chemicals to patients. A coating of thin film ceramic can protect an expensive tool from corrosion due to use in harsh environments.