Photoresist developers are used to remove the exposed parts of a photoresist. Photoresist ancillaries are chemicals which are used for dissolving unnecessary parts on a substrate. These techniques are both used in photolithography and photoengraving to create patterns on integrated circuits and other micro devices. The process relies on polymer modification chemistry, which alters the chemical make up of the photoresist so that it can be etched away. This allows for new circuit patterns to be built and formed.
Photoresist developers are responsible for the start of this process. As the chemical composition of the photoresist changes, a developer can be used to remove the unnecessary parts of it so that the desired pattern can be formed. There are two types of photoresist developers: positive, which makes the exposed region more soluble, and negative, when the irradiated region is less soluble. This way, the developer will either remove the photoresist along the pattern or remove the rest of the photoresist to create the pattern out of what is left behind.
Light wavelength must be determined and utilized before the developing or introduction of chemicals can begin. The most important lights are UV, DUV and H and I lines, which can be achieved from mercury-vapor lamps. What type of light used is proportional to the thickness of the photoresist. A thinner photoresist equals a shorter wavelength. The light used in this process weakens the photoresist so that the developer can be used on certain pieces of the resist.
There are several different polymer systems within photoresist systems. Some of these techniques include bisazide crosslinking, polyvinyl cinnamate, and novalaks. These are all forms of submitting chemicals that will naturally bond to each other to create a natural photoresist. Novolak photoresists particularly are high performing due to their ability to speed up production when in the presence of an additive, and are commonly used in the semiconductor industry for use as photoresist developers.
Photoresists and their chemicals meet the standards for several different industrial applications. Creating patterns for printed circuit boards are of course a great application for photoresists, and photoresist ancillaries like Ferric chloride can be to dissolve the unneeded substrate. Microelectronics are another huge industry for photoresists, as it focuses mostly in silicon wafers and integrated circuits. Photoresists are able to apply patterns to circuits and wafers needed to make them function correctly with the circuitry. Photoresists can also be used in sand carving, which uses photolithography, and glass etching, including specialty materials and MEMS. Photoresist technology is capable of meeting the needs of a number of applications from circuitry to art.
Photoresist developers and ancillaries aid greatly in the photoresist process and allow for the technology to take place. Once weakened by light, developers erode the photoresist so that the pattern can be laid down through the weakened part of the photoresist. Ancillaries chemically etch the substrate so that it creates a pattern for either circuitry or for a design like in a piece of art. This technology allows for circuit boards and integrated circuits to function through the laying of patterns, and by using energy from light, is more efficient then other possible techniques.