Development of superconducting quantum computer device fabrication technique Jan 2019 – present
I’m leading a fabrication team in Academia Sinica, Taiwan, and developing fabrication techniques for circuit quantum electrodynamic (c-QED) devices. Our fabrication process catches up with state-of-the-art techniques at present. In particular, I also developed an unique all electron-beam lithography (AEBL) lift-off approach by which one can fabricate ALL device components in one e-beam lithography step. This special technique characterizes as its simplified process and rapid chip producing time. It can avoid metal contact issue and surface contamination commonly seen in conventional photo/e-beam mix-and-match technique, and most importantly, the chip producing time from a blank sample can be suppressed within one day.
I take in charge or support fabrication for various type of devices, includes but not limited to:
- (in charge) Single/multiple superconducting qubit with diversified superconducting materials such as e-gun & MBE Al, NbN and TiN
- (in charge) Various parametric amplifier, including JPA, IMPA, and KITWPA, with decent signal gains
- (in charge) Superconducting single photon detector
- (support) Weak-link nanobridge superconducting cQED devices
- (support) Qubit based on 2D topological atomic-layer materials
Related works:
Superconducting qubit Fabrication by using one-step all electron beam lithography lift-off process
Development of nanofabrication and nanoanalysis Aug 2015 – Jan 2019
I was focusing on nanofabrication and nanoanalysis in Department of Materials Science and Engineering in National Taiwan University as a master student and Industrial Technology Research Institute as an associate researcher. The research topics were mainly on nanomaterials growth and analysis, and as a result I acquired comprehensive knowledge and skills, from mechanism of growth, fabrication technology, to material analysis. I also invented a breakthrough method for plan-view transmission electron microscopy (TEM) specimen preparation by using dual-beam focused ion beam (DB-FIB). By elaborately micro-machining and assembling, like playing with LEGO, we can fully protect sample surface from ion-induced damage and contamination. This approach is successfully applied to free-standing and supported single-layer graphene, the first time using DB-FIB to make site-specific plan-view TEM specimen on 2D atomic layer materials.
Related works:
Plan-View Transmission Electron Microscopy Specimen Preparation for Atomic Layer Materials by Focused-Ion Beam
Grafting Methyl Groups on Si (111) Surface as a Buffer Layer for van der Waals Epitaxial Growth of ZnO Nanorods in Chemical Bath Deposition
Low-power Resistive Random Access Memory by Confining the Formation of Conducting Filaments
In-situ Scanning Electron Microscopy Observation of MoS2 Nanosheets during Lithiation in Lithium Ion Batteries
FIB GENIUS project: a proposed FIB operating simulation software aiming at promising FIB education & training market July 2020 – Jan 2021
Dual-beam focused ion beam (DB-FIB) is an essential nano-analysis instrument in both industry and academy due to its irreplaceable micro-machining and micro-manipulating capability, especially when electronic devices have been scaling down to an astonishing size nowadays. However, operation of DB-FIB highly relies on experience, and therefore training of DB-FIB requires massive time and effort for both trainers and trainees, plus heavy financial burden due to its costly maintenance fee. To this end, I propose a FIB GENIOUS solution: an operating simulation software which can simulate DB-FIB functions and user interface, like an aviation training software for pilots. The brand-new FIB GENIOUS idea can benefit all aspects of DB-FIB:
For user
- A practice tool
- Develop new FIB technique
For supervisor
- Evaluate user
- Reduce training cost
For manufacturer
- Release beam time
- Develop high-risk technique
To realize this idea, one crucial factor is how to reproduce DB-FIB’s every effects in software. Thanks to the fact that I’m one of the best FIB user on the planet (no joking) and have some programming knowledge, I’m confident being able to describe all dominant mechanism, from ion optics, ion-sample interaction, to software interface, in a programmable way. At present, a 80-page document of software requirement specification has been done, and the FIB GENIUS project is seeking for software developers for cooperation.
Development of electron diffraction simulator with user-friendly GUI for crystallography analysis July 2014
This small cool gadget is a self-developed MATLAB program which I attempted to further improve my coding skill after finishing an optional programming course in undergraduate school. Combining my computational capability and materials science background, this simulator can calculate and output electron diffraction information containing virtual patterns and intensity distribution. It provides not only educational materials but also a practical tool to solve crystallography problems. The project won a top 4 finalists in a national MATLAB programming contest.
Lan-Hsuan Lee 