Axel Walter

Title: The Innovative Contributions of Axel Walter

Introduction

Axel Walter is a notable inventor based in Voerde, Germany. He has made significant contributions to the field of integrated circuit technology, particularly in the area of plasma etching processes. His work focuses on enhancing the efficiency and effectiveness of etching carbon-based low-k materials.

Latest Patents

Walter holds a patent for a process titled "High-density plasma etching of carbon-based low-k materials in an integrated circuit." This innovative plasma etching process is designed for etching a carbon-based low-k dielectric layer in a multi-layer inter-level dielectric. The low-k dielectric may be divinyl siloxane-benzocyclobutene (BCB), which contains about 4% silicon, with the remainder being carbon, hydrogen, and a little oxygen. The etching process utilizes a combination of gases, including oxygen, a fluorocarbon, and nitrogen, while avoiding argon. An N2/O2 ratio of between 1:1 and 3:1 is crucial for producing vertical walls in the BCB.

In a dual-damascene structure, the inter-level dielectric comprises two BCB layers, each underlaid by a respective stop layer. The process requires photolithography with an organic photoresist, necessitating a hard mask of silicon oxide or nitride over the upper BCB layer. After the BCB etch has cleared all the photoresist, the bias power applied to the cathode supporting the wafer must be set to a low value, while the separately controlled plasma source power is set reasonably high. This adjustment helps reduce faceting of the exposed hard mask. Chamber pressures of no more than 5 milliTorr enhance the selectivity of BCB over photoresist, while substrate temperatures of less than 0°C increase the BCB etch rate.

Career Highlights

Walter is currently employed at Applied Materials, Inc., where he continues to develop and refine his innovative etching processes. His work has contributed to advancements in the semiconductor industry, particularly in the production of more efficient integrated circuits.

Collaborations

Walter has collaborated with notable colleagues, including Zongyu Li and Karsten Schneider, to further enhance the research and development of plasma etching technologies.

Conclusion

Axel Walter's contributions to the field of integrated circuit technology through his innovative patent