Contrast enhancement material, or CEM, is a photo-bleachable material applied to the photoresist surface then removed with DI water pre-wet. There are many benefits to using contrast enhancement material. For one, the contrast enhancement materials, if matched correctly with the exposure parameters, will absorb light from light scattering in the dark areas before they reach the resist surface. As a result, vertical sidewalls will be much straighter and rounded or pointed edges at the tops of features will be eliminated. Contrast enhancement material increases the contrast of the illumination that can reach the photoresist. It has a simple, or low defect process and can increase the depth of focus 20-40%. Contrast enhancement material extends the resolution limit and even extends the life of the exposure tool. It reduces rework and increases yields.
Everything about semiconductor integrated circuits is susceptible to damage by dust and any particulate matter in the air. Pellicles were developed in response to the need for everything in the cleanroom to be dust free. Pellicles are 1mm thick polymer membranes. During photolithographic reproduction of integrated circuits, they act to prevent dust particles on the surface of the photomask from imaging into the photoresist coated quartz wafer. Various pellicle grades exist: some are designed for KRF, some for dry ARF and others for immersion ARF excimer laser lithography. Pellicles can increase usage life of various electronic materials, and pellicles guarantee increased life for photomasks and reticles.
As LCD panels are used in more and more devices, the demand for larger sizes and finer images in the LCD panel also increases. But the bigger the screen, the more elements are needed. Also, the closer together these elements must be: 10 micron meters or less from each other. This demand for size, high resolution and clarity all in one single material presents a challenge to engineers. The quartz wafer crystals must be manufactured with great precision and is the best answer to this demand for larger, finer LCD panel displays. The material of choice is synthetic quartz wafers. Synthetic quartz wafers offer excellent thermal resistance and light transmission properties. It is a high grade synthetic product, and therefore is free from bubble and foreign matter. Synthetic quartz has a lower thermal expansion than ordinary glass, but a high permeability over the whole wavelength range from the ultraviolet to the infrared region.