This inventor holds 6 USPTO granted patents. Top assignees: International Business Machines Corporation, Globalfoundries Inc.. Active years: 2001-2019.
Company Filing History:
4 out of 166,159 
2 out of 5,671 
Years Active: 2001-2019
Title: Richard E Wistrom: Innovator in Photomask Technology
Introduction
Richard E Wistrom is a notable inventor based in Essex Junction, VT (US). He has made significant contributions to the field of photomask technology, holding a total of 6 patents. His work has been instrumental in advancing methods used in chip fabrication.
Latest Patents
Wistrom's latest patents include innovations such as a photomask blank that incorporates a thin chromium hardmask. This invention outlines methods for manufacturing photomasks, photomask blanks, and photomasks utilized in chip fabrication. The process involves forming a phase-shift layer on a mask blank, followed by a hardmask layer, and a layer stack that is crucial for creating a photomask blank. The layer stack consists of a first layer made of a specific material and a second layer that can be selectively etched. The design ensures that the first layer is thicker than both the second layer and the hardmask layer. This photomask blank is essential for patterning features in chip areas during manufacture. Another significant patent relates to a lithographic mask substrate structure, which includes a sub-resolution assist feature (SRAF) on a quartz substrate, enhancing the manufacturing process of lithographic masks.
Career Highlights
Throughout his career, Richard E Wistrom has worked with prominent companies such as IBM and Globalfoundries Inc. His experience in these organizations has allowed him to refine his expertise in photomask technology and contribute to various innovative projects.
Collaborations
Wistrom has collaborated with notable individuals in the field, including Daniel Shaw Brooks and Phillip Francis Chapman. These collaborations have further enriched his work and contributed to advancements in photomask technology.
Conclusion
Richard E Wistrom's contributions to the field of photomask technology are significant and impactful. His innovative patents and collaborations highlight his role as a leading inventor in this specialized area.