Weilun Chao

Title: Innovations of Weilun Chao in Silicon Micromachining

Introduction

Weilun Chao is a notable inventor based in El Cerrito, California, recognized for his contributions to silicon micromachining techniques. With a total of two patents to his name, Chao has developed innovative methods that enhance the precision and quality of etching processes in semiconductor manufacturing.

Latest Patents

Chao's latest patents include a method for etching radical controlled gas chopped deep reactive ion etching. This method focuses on high aspect ratio reactive ion etching with gas chopping, which produces scallop-free, smooth sidewall surfaces. By utilizing precisely controlled, alternated gas flows of etching and deposition gas precursors, Chao's technique allows for a controllable sidewall passivation that achieves high anisotropy. The dynamic control of sidewall passivation is accomplished by managing fluorine radical presence with moderator gases, such as CH, and adjusting the passivation rate and stoichiometry using a CF source. This innovative approach significantly reduces sidewall ripples, achieving silicon features with an aspect ratio of 20:1 for 10 nm features, making it applicable to nano-applications in the sub-50 nm regime.

Another significant patent involves nanometer-scale ablation using focused, coherent extreme ultraviolet/soft x-ray light. This technique enables the ablation of holes as small as 82 nm with clean walls on a poly(methyl methacrylate) substrate. By focusing pulses from a Ne-like Ar capillary-discharge laser, Chao demonstrates the potential for direct nanoscale patterning of materials, showcasing the effectiveness of focused coherent EUV/SXR light.

Career Highlights

Chao has worked with prestigious institutions, including the University of California and the Colorado State University Research Foundation. His work has significantly advanced the field of silicon micromachining, contributing to the development of more efficient and precise manufacturing techniques.

Collaborations

Chao has collaborated with notable colleagues, including Deirdre Olynick and Ivo Rangelow, further enhancing the impact of his research and innovations in the field.

Conclusion

Weilun Chao's contributions to silicon micromachining and nanotechnology exemplify the importance of innovation in advancing semiconductor manufacturing techniques. His patents reflect a commitment to improving precision and efficiency in the industry.