The halftone technique renders different levels of "gray" by varying the density of very small geometry on the photomask. The geometry is large enough to resolve on the photomask but too small to resolve in the photoresist. Even though it doesn't print on the photoresist, the density of this geometry attenuates the amount of energy the photoresist receives. This allows you to create very special three-dimensional structures in the photoresist. To design a grayscale mask for optical lithography you'll first need to know how varying the optical density on the mask will affect your specific lithography process. You characterize your process by first running a calibration mask to quantify this relationship. The information gained from the calibration mask is used to develop a model to produce masks that are optimized for your specific lithography process. Contact us if you need assistance with this process. At PhotomaskPORTAL, we help researchers design and build low-cost, high-quality photomasks.
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May will be the final month of our LayoutEditor contest. To enter the contest (and have a chance to win FFFFAB-u-lous prizes), simply create a video tutorial on any aspect of using LayoutEditor software and upload the video on YouTube. The tutorial can be on something basic (like how to select objects) or on something complex (like FastCap and FastHenry) -- you decide. You can use an application like QuickTime Player to screencast your video. If you need a temporary license to LayoutEditor to make the video, just ask us for one on our contest page. Okay, so I am borrowing heavily from one of my favorite movies American Beauty ... where the supporting character Ricky is in awe of wind playing with a plastic bag for a full ten minutes ... but it's true. Beauty is all around us ... if you know where to look.
You can see it clearly in this photo taken be Lee Aspitarte as he delves into the physics of a new class of 2D graphene-like semiconductors called transition metal dichalcogenides for the Minot Research Group at Oregon State University. Shown is an exfoliation grid made from a layer of gold on top of a silicon wafer. Take a minute and enjoy this beautiful picture taken at micro-scale. For reference, the dots are 2-micron contacts and the width of a single human hair would span across four of the dots. At PhotomaskPORTAL, our mission is to provide researchers at universities, labs, and start-ups with an easy path to low-cost, high-quality photomasks. Low-cost and high-quality are obvious but what do we mean by "Easy Path"?
One way we provide researchers an easy path is with a simple, streamlined process based on modern eCommerce systems with up-front pricing. Do you really have time to solicit multiple quotes? Do you really know who the right companies are to talk to? While we can provide you with a quote if you require one, you don't need one to transact with us. Simply go in our store, select your product and the fundamentals needed to build it (tone, mirror, resolution), and check-out. Upload your data and be done in 15 minutes. We also make it easy by giving you access to a broad network of world-class photomask manufacturers, not matter how simple or complex your requirements, you can find what you need through our one website. Need a film mask for the 80-micron channels on your microfluidic device? No problem. Need a grating pattern pattern with 125nm bars for your microscopy experiment? No problem. How about a large-area mask more than one-square-meter needed for the techno-art you have been commissioned to build for the Smithsonian? No problem. Another way we provide an easy path is by providing mask layout software and templates in our store and our library. And if your photomask design objectives are more ambitious, we also provide design support service. Simply give us a Statement of Work describing your project and what you need and we can work-up a custom design to meet your requirements. This can be very basic or very complex. Perhaps you need a test reticle to characterize the steppers in your fab for process development, or maybe you need a grayscale mask for shaping the photoresist on your MEMS device, or perhaps you need optical-proximity correction applied to your features. Or perhaps you simply want masks without tying up your resources in the whole design and fabrication process. Whatever your requirements, at PhotomaskPORTAL, we make it easy to make a mask. Precision Semiconductor Mask Corporation (PSMC) was incorporated in Taiwan in 1997. I called on their maskshop in Hsinchu in the late 90's for DuPont Photomasks. In 2000, US-based Photronics acquired the majority share of PSMC, changed the name to Photronics Semiconductor Mask Corporation, and made the maskshop their foothold for expansion in Taiwan. In 2006 Photronics would build a second maskshop in Taichung focused on large area masks for flat panel displays that has proven to be a big success. As of this week, Japan-based Dai Nippon Printing (DNP) and Photronics have officially merged their PSMC and DPTT (DNP Photomask Technology Taiwan) assets in a joint venture. So PSMC changes names once again, this time to PDMC (Photronics DNP Mask Corporation), and becomes even stronger. Be sure and check out the LIBRARY section inside our Store. In here we keep gds-II layout templates for both glass masks and film masks and well as a simple collection of alphanumeric characters. You can use software like LayoutEditor to draw your topcell in the template of your choice to see how it will look on the mask. Even though the templates are located in our Store, there is no charge. Think of these like free samples at CostCo.
Silver-Halide Emulsion -- the Technology of Film Masks -- Still Going Strong After All These Years!3/21/2014 Film masks offer a very cost-effective path to photolithography. If your features are several tens of microns across, then this is certainly an option for you. If you area doing soft lithography with channels 80-100um across, then film masks are an efficient means to an end.
Although commonly referred to as transparency masks, film masks are not "transparencies", at least not the kind I used to generate with a laser printer shortly before each presentation. Film masks are essentially a large sheet of photographic film that have been exposed with light from a plotter (hence the other common name: photoplots). After exposure, the film is developed, fixed, and dried in a dark room. Whereas a hard mask typically consists of chrome-on-glass, a film masks consist of emulsion-on-polyester. The emulsion is a mixture of silver-halide salts suspended in a colloidal material such as gelatin. The emulsion offers much higher optical density than what you would get from spewing toner out of a laser printer. Still with me? Then you should read the following well-written article describing the history and technology of emulsion in much greater depth.
Film masks are very low-cost photomasks often used to build molds with SU-8 photoresist for building PDMS microfluidic chips with soft lithography. Our film masks never take more than a day to manufacture and often can ship the same day.
Now if we can just get our microfluidic chips loaded in our store .... Absolutely nothing! Well maybe something. But definitely not for modern-day communication of quality parameters associated with the manufacture of high-tech tooling such as a photomask. At PhotomaskPORTAL, we provide product documentation such as the Certificate of Conformance on request in a variety of digital formats by eMail or FTP. We can also permanently embed these results on the photomask itself with the addition of a QR code. Scan this with a smart phone and ... Voila! Your quality documents appear on whatever device you choose to read them on. And you don't have to shred them when you're done. Alternatively, you can use this QR code to attach any document you want to your photomask. This could be the design parameters, the design review, the design data, the SBIR application, ... you get the idea. We do this not only because it is environmentally-responsible, but also because it makes using our product easier. And that is our fundamental goal at PhotomaskPORTAL: to give researchers like you an easy path to low-cost, high-quality photomasks. |