State of the Art Patterning
Materion has made significant investments over the last year to increase our optical coating capability of wafers in order to support the growing trend in wafer level packaging of thermal imaging devices. In addition to a new 3000 square foot, class 1000 clean room space, Materion has also installed several state-of-the-art wafer processing tools that greatly increase our pattern generation capabilities. In addition to wafers for thermal imaging, these new tools offer great possibilities for other customer applications as well.
Custom 3D Patterning Tool
Our new custom 3D patterning tool is a fully automated, recipe-driven machine that uses robotics to spray coat 150mm to 200mm wafers. The machine can process cassettes of twenty five wafers at a time with an operator only required to load the cassette and start the recipe. This level of automation will help to ensure the maximum level of photo-resist coating uniformity across topographies with a depth of hundreds of microns.
Advantages of the New Tool
The tool is specifically designed to provide resist deposition that can be used in Materion’s vacuum chambers at various high temperature coating processes. The patterning tool also has multiple automated heating and cooling plates, automated alignment to notches and flats, and capabilities that decrease patterning time per wafer. These combined factors will increase throughput, reduce human error and decrease cost.
The alignment tool is used to align photo mask to wafers in order to create a pattern. It has the capability to align photo mask on a 200mm wafer using features on the order of 5um with an automated process or manual process. This allows for more accurate deposition within the cavity or on the substrates. Once the photo mask is aligned to the wafer, a collimated beam of UV light exposes the pattern. The wafer is then developed in the 3D patterning tool and sent for coating.
The custom Lift-Off Bench is a cassette-driven process tool. It has automated mechanical agitation which promotes reduced lift-off times. It also has a robotic module which removes all residual lift-off material and reduces overall defects across the wafer through a unique cleaning process.
Filter Arrays and Patterning Capability
We have long been a technology leader for Multispectral Filter Arrays. With our new work cell, the capabilities will be leveraged to meet reduced tolerances and filter sizes. Currently, we can assemble arrays with a pitch tolerance of 5um, over 130 elements, and a pitch width of 32um from center to center. The new tool will enhance our ability to pattern the assembled arrays, thus allowing the customer to order potentially any size or shape for the patterned array product line. This line can be used across the space, defense, and commercial markets.
Materion will also explore such areas as: thin film coatings directly on Si detectors; Pixel level Coatings, which are known primarily for RGB and NIR coatings, on imaging detectors; and precise order sorting filters with reduced feature sizes at higher volumes.
With more than 30 years of photolithography experience in patterning filters, we expect to use this along with the new equipment to provide new coating options. In addition, the Wafer Level Work Cell is expected to be in production by the end of 2013. Our customers will greatly benefit from these investments as new projects require custom solutions from Materion’s Thin Film Coating Division. For more information on patterning capability or filter arrays, please contact Robert Legg, Commercial Business Development Manager, Robert.Legg@Materion.com.