View in browser

Nano3 is committed to continuously improving and providing our users with the most updated tools. We are excited to announce that as part of this effort, Nano3 will be replacing the existing chemical fume hoods in the wet etching room and the photolithography rooms, ensuring a safer and more efficient working environment for our users. The project is expected to start in early May of 2025 and will involve replacing all 4 chemical fume hoods in the wet etching room 1443 and all 3 stainless steel chemical fume hoods in the lithography rooms, 1413 & 1417, with new ones. Although the exact duration of the project is uncertain, we will strive to minimize the impacts to our users, as we understand the importance of these facilities in their research and work. By replacing the old chemical fume hoods, we aim to provide a better working environment and reduce potential hazards, as chemical fume hoods are crucial to the safety of all our users. We'll send out notices when we have more updates.

We've been continuously making improvements to the essential Deep Silicon Etching (Bosch) process on both the Plasma-Therm and the Oxford P100 ICP-RIE dry etchers, in response to the desire of a higher Si-to-Photoresist (Si/PR) selectivity. With the newly developed 3-Step Bosch processes, we've demonstrated a Si/PR selectivity of >200:1 (previous 60~80) on the Plasma-Therm etcher, and ~190:1 (previous 70~90) on the Oxford P100 etcher.

In addition to the higher Si/PR selectivity, the new processes also produce much smoother side walls, which is essential for various applications.

With using SiO2-on-Si carrier wafers, the Si etching rate is about 0.9 um/cycle (~5 um/min), which may vary depending on the exposed area of Silicon. Our staff has thoroughly tested the repeatability of the new process, confirming its ability to deliver consistent high performance, and ensuring the reliability of the etching process. 

For more questions or assistance regarding the Bosch process on the two dry etchers, please contact Dr. Jeongho Ha at jeh166@ucsd.edu. 

Utilizing a newly purchased low-frequency (LF) RF power supply for the Oxford PECVD system, we've re-established the highly desired stress-tunable Silicon Nitride (SiNx) deposition process and made it available to all users. We've demonstrated that the stress and refractive index of the deposited SiNx film can be precisely controlled by adjusting various process parameters like the LF pulse widths and durations, allowing for the creation of films with either compressive or tensile stress, or zero stress, depending on the desired application. This level of control is essential in ensuring the quality and reliability of the deposited films, and we are committed to continuously improving and optimizing our processes to meet the evolving needs of our users.  

For more questions or assistance regarding this process, please contact Dr. Kin Wong at jklw013@ucsd.edu. 

We're committed to continuously improving existing processes and creating new ones to meet the evolving needs of our users. For the latest process updates, please visit our website at https://nanofab.ucsd.edu/resources/, where you can find details about newly created processes, such as the SiC and amorphous Silicon PECVD processes, and the process for creating excellent Lift-off profiles on thick photoresist layers.

We encourage you to challenge us and share your needs, and we'll work together to find solutions. Your feedback is valuable to us, and we're always looking for ways to enhance our services. 

We are excited to update you that the new Deep Silicon Etching (DSiE) & Atomic Layer Etching (ALE) System, Oxford PlasmaPro Cobra 300, has been delivered to Nano3, and we've completed the first phase of its installation process. In the second installation phase, the Oxford process engineers will work with us on demonstrating the performance of their newest Bosch and Cryogenic Deep Silicon Etch (Cryo-DSiE) processes, which will enable us to achieve higher precision and control in our etching processes. We'll also develop new ALE processes for various materials such as SiNx, SiO2, which will expand our capabilities and potentially lead to breakthroughs in many fields. This new system will play a crucial role in supporting our research and development efforts, and we look forward to exploring its full potential. Please be on the lookout for future updates, which will be shared on our website and via email, and we encourage you to reach out to us with any questions or feedback.

We would like to remind our users to be more mindful when using chemicals, photoresists, and all other lab supplies, such as cloth wipes, provided by Nano3. It has come to our attention that some users have been utilizing general chemicals, such as Acetone, RR41, AZ MIF Developers, etc., and other lab supplies in excessive quantities, far exceeding their actual needs, which is a concern for Nano3 as it increases the volume and frequency of waste pickups and associated costs.

We encourage users to adopt more sustainable practices, such as reusing chemicals for processing smaller samples before discarding them into waste bottles, and being more thoughtful in their use of lab supplies, like using only the necessary number of wipes and choosing the most suitable type of wipe for the task.

By being more mindful of chemical and lab supply usage, we can work together to minimize waste and reduce costs, which is particularly important given the recent increase in their prices. We appreciate your attention to this matter and encourage you to reach out to us if you have any questions or concerns about chemical and lab supply usage or waste reduction.

We invite you to highlight your research in Nano3's new posters, as we continue to update our displays to showcase the latest advancements and innovations emerging from our facility. 

This is a great opportunity to share your work with the broader research community and highlight the impact of Nano3 in driving innovation and discovery. By showcasing your research, you'll be contributing to the vibrant and dynamic environment that Nano3 fosters, and helping to inspire new ideas and collaborations.

If you're interested in having your research featured on our new posters, please don't hesitate to reach out to Nano3's Technical Director, Dr. Fubo Rao, at furao@ucsd.edu.