Periodic Structures at a glance

Who we are:

Periodic Structures Inc. is an early development stage start-up company developing practical Lithography Solutions based on Interference. The Founding Team has a strong background and a proven track record in the Semiconductor Equipment industry and is known for having brought practical Lithography solutions to the Market. We know the Semiconductor Equipment Market very well and have a vast network of Industry Connections. Our team is the core pivot point for the successful development of Interference-based Lithography solutions.

What we do:

Memory and logic layouts have adopted highly regular structures (one-directional lines and spaces in one layer) with design-dependent line end locations and gap spacings starting in the 45nm technology node. Patterns that adhere to such highly regular layouts do not require the generic capabilities of general purpose lithography tools, which have reached astronomical costs - in order to maintain the flexibility of generic capabilities. Limiting the patterning capability of exposure tools to those highly regular structures allows significant simplification of the projection optics, which reduces the costs of producing and using such lithography tools. The apparent optical solution for generating highly regular one-dimensional structures is an interference-generated pattern, and this is our chosen technical approach. Our goal is to produce an affordable high performance lithography tool that provides one or two exposures of a multi-exposure or multi-pattern process and that will be combined with an exposure to define the line ends and cross-line interconnects.

Interference technology is not new but it has not been commercially adopted due to its inherent restrictive imaging characteristics; HOWEVER, the design technology is now on an intersection path with the characteristics of Interference lithography. The time to start the process of making a tool and process available is now. We consider Interference Lithography as the optical lithography of last resort, extendible to the 11nm technology node, currently the projected entry point of EUV in production. The technology also enables vector or cell-projection direct-write applications by making so only the gaps are opened with in a line or connected between lines.

We are looking for technical and business partners. Please contact us and join the future of lithography!

Our Founders

Rudi Hendel has spent his entire career in the Semiconductor industry - processing, equipment design and development as well as Technical and Strategic Marketing. He held positions at Tektronix, AT&T Bell Laboratories, GAIN Electronics, Sony/MRC and Applied Materials. Rudi has worked on establishing the feasibility of Interference-based Lithography at Applied Materials and has founded Periodic Structures Inc. with John Petersen and Dave Markle to make Interference-based Lithography a commercial reality. Rudi is a member of the SPIE and IEEE, has published numerous papers and owns one patent and has a number of patents pending.

Dave Markle has hands-on experience in designing practical Lithography equipment (that is actually used in production) based on his work at Ultratech and earlier at Perkin Elmer. Dave is an acknowledged "legend" in the semiconductor capital equipment industry - see, Legends, Dave Markle: The Development of the Projection Printer. Dave has spent his entire career in the semiconductor equipment industry and retired from Ultratech in January of '08. His awards include a SEMI Award from the Semiconductor Equipment and Materials Institute with Messrs. Buckley, Hemstreet and Offner, 1979, the David Richardson Medal from the Optical Society of America 1994, membership in the National Academy of Engineering since 2004 and a Lifetime Achievement Award, BACUS-SPIE, 2008. In 2013 Dave was awarded the Frits Zernike Award, which is SPIE's highest honor for a lithographer. Dave is a member of the OSA, SPIE and IEEE and holds over 50 US patents.

John Petersen has extensive experience in all aspects of lithography and a strong modeling background. John has been heavily involved in advanced design and manufacturing of photomasks for extremely high resolution optical lithography. He has experience from Texas Instruments, Shipley Company, SEMATECH and Petersen Advanced Lithography, Inc. John is co-developer of the 2006 SEMI Innovation Award winning Maxwell equation solver EMF3. He began his direct involvement with interference lithography working with Steve Brueck at the UNM as a technical advisory board member of the Nanolithography MURI. John is a Fellow of SPIE. He has published sixty-five papers, taught advanced optical lithography for many years and holds six patents. He is known worldwide for describing the chemical-physics of chemically amplified resists (Byers-Petersen Reaction Diffusion Equations) and for his work in advanced optical lithography.


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Papers and Presentations

Interference Assisted Lithography (IAL): A Way to Contain the Lithography Costs for the 32nm and 22nm Half-Pitch Device Generations (pps) Right click and save as

Interference Assisted Lithography for Patterning of 1D Gridded Design (pdf)

Exploration of Linear and Non-Linear Double Exposure Techniques by Simulation (pdf)