A photomask is an opaque plate with holes and transparent areas that allow light to go through the plate in a specific pattern. Photomasks are widely used in photolithography for the production of integrated circuits, photonic devices, and micro-electro-mechanical systems. Usually, a photomask consists of fused silica or glass substrate that is coated with an opaque film, into which a replica of the device design pattern is etched. A binary pattern that replicated an original design of the device constitutes the photomask image. This image is used to direct light in a particular pattern in order to ‘print’ the design on the silicon wafer or another substrate.
While the photomasks are becoming smaller and smaller, the threshold for potential photomask flaws and defects is decreasing. The control of pattern defects is the most critical issue of the production of high-end photomasks. The repairs may include carbon patch trimming, sequential defect removal, etc. The leading method of photomask repair has become micromachining as it is an extremely accurate method of subtractive removal of opaque mask defects. Micromachining utilizes the atomic force microscopy technology.
Micromachining has several advantages, some of which include the ability to machine in tight geometries, high image resolution, the ability to develop custom repair processes, etc.
Optromix – a fiber laser vendor – has developed a custom fiber laser for photomask repair applications. The laser that is used in photomask repair is a fiber DUV laser that replaces an argon-ion laser. Fiber DUV laser provides several advantages over other types of lasers. For instance, fiber DUV laser does not require a cooler, whereas an argon-ion laser requires a constant supply of running water to cool down. Another advantage is a higher power output which improves the efficiency of photomask repair. Overall, fiber laser photomask repair has improved significantly through the use of fiber DUV laser provided by Optromix.
The importance of photomasks and their repair is hard to overestimate. Photomasks are essential in the production of most modern electronics. The photomask repair and upkeep is equally as important as it helps to improve the quality of production.
Optromix Inc., headquartered in Cambridge, MA, USA, is a manufacturer of laser technologies, optical fiber sensors, and optical monitoring systems. We manufacture lasers using our own technologies based on the advanced research work and patents of international R&D team. Laser processes are high quality, high precision, easily-automated manufacturing solutions that provide repeatability and flexibility. If you have any questions about fiber DUV lasers please contact us at info@optromix.com
