D2S offers curvilinear solutions in the pixel domain to create curvy mask features and open the door to curvy designs. Curvilinear mask features have been shown not only to print more accurately, but also to print more reliably, which is good for both mask and wafer quality.
Curvy = Pixels
The advent of the multi-beam mask writer was a key to enabling practical application of curvy mask shapes. Multi-beam mask writers are pixel-based and therefore shape-agnostic when it comes to runtime – all masks with any shapes print within the same time. This opened the door for curvilinear mask shapes to become more pervasive without the runtime penalties that had been a major obstacle in the past.
With mask writing lined up for full-chip curvy solutions, the questions about the viability of curvy solutions have turned to the rest of the manufacturing process.
Manufactured shapes on the mask have always been curvy, and manufacturing has always lived in the pixel domain, so while a wholesale change to curvilinear features may require some tweaking, all the tools and processes – including metrology, inspection, and repair – are able to handle curvy shapes.
However, edge-based computer-aided design (CAD) processing will be slower in the world of curvy masks. D2S pixel-domain solutions address this issue.
Pixel Domain = GPU-Based Computing
The shift to the pixel domain for masks naturally leads to the use of GPU-accelerated computing, which excels in pixel-domain computation. The D2S Computational Design Platform (CDP), with its GPU-accelerated approach, was a major enabler for the D2S TrueMask® ILT breakthrough for full-chip curvilinear ILT masks.
The D2S GPU-accelerated pixel-level dose correction (PLDC) technology in the NuFlare Technology multi-beam writers performs mask process correction at the same time as the machine writes the mask. The result is zero impact on turnaround time for all mask shapes, including curvilinear masks. In addition, GPU-based computing is a foundation for most deep learning (DL) computations, which have become an important tool for complex, computation-heavy applications.
Opening the Door for Curvy Design
With the entire manufacturing chain ready for curvy, the door is open for curvy designs. The benefits of a curvy chip – smaller, faster chips that use less power – are a powerful enticement to look at curvy solutions on the design side as well.
In the meantime, D2S curvilinear solutions in the pixel domain are helping to drive next-generation manufacturing and paving the road for design to take the same path.