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Home Research Publications Patents People Gallery Lab Facilities Teaching Links Current Event NEWS 2020 van der Waals epitaxy leads to high quality TMDC growth : our paper, "Hybrid Integration of n-MoS2/p-GaN Diodes by Quasi-van der Waals Epitaxy," is accepted by ACS Appl. Electron. Mater. 2019 Congratulations to Wonsik for passing his PhD final exam! Congratulations to Lukas for winning the ECE Indira Gunda Saladi Engineering Research Prize! Our rolled-up power inductor paper entilted, " Monolithic mTesla Level Magnetic Induction by Self-Rolled-up Membrane Technology ," is now accepted by Science Advances ! Congratulations to all the authors, including our collaborators from the POETS and DOE centers! In this work, we reported power inductors with unprecedented high density and large current handling capability by geometric transformation of centimeter long 2D nanomembranes into more than 21 turns 140 um diameter air-core microtubes, followed by post-rolling integration of ferrofluid magnetic materials. It represents another milestone in the scalability and device performance based on the S-RuM nanotechnology platform. Prof. Li has been elected a Fellow of the Optical Society of America , for her pioneering contribution to nanostructured semiconductor materials growth and fabrication innovation for device applications! Our paper, " Effect of Perforation on the Thermal and Electrical Breakdown of Self-Rolled-up Nanomembrane Structures " is published in Adv. Mater. Interfaces ! Congrats to Julian and all co-authors! Our paper, " CMOS Compatible Catalyst for MacEtch: Titanium Nitride Assisted Chemical Etching in Vapor Phase for High Aspect Ratio Silicon Nanostructures " is accepted by ACS Appl. Mater. Interfaces ! Congrats to all authors, including our industry partner from Lam research! This work represents significant advancement of the MacEtch (metal-assisted chemical etch) technology with its CMOS-compatibility by using TiN catalyst and scalability by going to vapor phase! Our paper, " High Aspect Ratio Ga2O3 Fin Arrays with Low-Interface Charge Density by Inverse Metal-Assisted Chemical Etching ," is published in ACS Nano ! Conglratulations to Hsien-Chih Jack, Munho, Kelson and all of the coauthors! This work has been featured by numerous news outlets including Phys.org , EurekAlert! , ScienceDaily , AZOMaterials, and I-Connect007 . Our paper, " Monolithic radio frequency SiNx self-rolled-up nanomembrane interdigital capacitor modeling and fabrication ," is published in Nanotechnology ! This is yet another demonstration of using S-RuM nanotechnology to miniaturize the footprint and enhance the performance of passive electronic components! Two more patents on MacEtch (metal-assisted chemical etch) are issued: Catalyst-Assisted Chemical Etching with a Vapor-Phase Etchant (Patent number 15/712,498); and Optoelectronic device including a buried metal grating for extraordinary optical transmission (Patent number 15/200,345). Two more patents on S-RuM nanotechnology are issued: Helical antenna and method of modulating the performance of a wireless communications device (Patent number: 15/408,893); and Rolled-up power inductor and array of rolled-up power inductors for on-chip applications (Patent number: 15/704,262). Congratulations to Wonsik for passing his prelim exam! 2018 Prof. Li has been elected a Fellow of the American Physics Society , " for her seminal contributions to the fundamental understanding and technical innovations to epitaxial growth, fabrication, and applications of semiconductor nanowires and nanomembranes, towards making electronic and photonic devices smaller, faster, and cheaper. " Congratulations to Dr. Wen Huang for accepting a full professor position at Hefei University of Technology in China! Congratulations to Dr. Munho Kim for accepting a faculty position at Nanyang Technology University in Singapore! Our paper titled " Enhanced performance of Ge photodiodes via monolithic antireflection texturing and α -Ge self-passivation by inverse metal-assisted chemical etching ," with Munho Kim as the lead author, has been published in ACS Nano ! The periodically texutured surface and the simultaneous formation of amorphous Ge ( α -Ge) directly from I-MacEtch lead to the increase of photocurrent and reduction of dark current for a metal-semiconductor-metal (MSM) photodiode, all with one processing step! Our paper tilted " Three-dimensional radio frequency transformers based on a self-rolled-up membrane platform ," with Wen Huang as the lead author, has been published in Nature Electronics ! A News and Views article on this paper written by Dr. Macrelli appeared in the same issue. The rolled-up transformer SEM image has been selected as the " hero image " to highlight the May issue. In this work, we report high-performance ultra-compact on-chip RF transformers based on the monolithic 2D for 3D self-rolled-up membrane (S-RuM) platform. The much more desirable scaling behavior of the index of performance as a function of turns ratio than conventional planar designs is attributed to the almost ideal mutual magnetic coupling inherent to the S-RuM 3D architecture. This work has been featured by numerous news outlets including Eurekalert , eeNewsEurope , and Analog IC Tips . Our paper titled "Self-Anchored Catalyst Interface Enables Ordered Via Array Formation from Sub-micron to millimeter Scale for Poly- and Single-Crystalline Silicon," with JD and Munho as the lead authors, is published in ACS Appl. Mater. Interfaces . This is yet another variation of MacEtch with S elf- A nchored- C atalyst ( SAC-MacEtch ) that enables directional etching for otherwise challenging structures including large lateral and deep vertical dimensions, as well as polycrystals. Wen and Prof. Li published a News and Views article, titled "Downscaling inductors with graphene", in the inaugural issue of Nature Electronics . Professor Li will be serving as the Vice President of Finance and Administration for IEEE Photonics Society. 2017 Our paper on MacEtch (metal-assisted chemical etching) of the technically important InxGa1-xAs semiconductor, led by Lingyu, has been accepted by ACS Nano ! This is the first successful demonstration of low bandgap and ternary semiconductor etching using MacEtch. Combined with digital etching, ordered In0.53Ga0.47As nanopillar arrays with perfectly damage-free and smooth sidewalls, as confirmed by the interface characterization using MOSCAPs, are realized. Congratulations to Dr. Paul Froeter for completing his PhD degree and becoming the Engineering Teaching Lab Specialist right here in the department! Congratulations to Wen Huang for completing his PhD degree and staying as a postdoc in the group to lead the S-RuM subgroup! Congratulations to JD Kim and Eric Searbron for passing their PhD final exams and embarked on their new journeys at Intel and Northrop Grumman, respectively! Another patent on MacEtch (metal-assisted chemical etch) is issued: " Apparatus and Method for Magnetic-Field Guided Metal-Assisted Chemical Etching ," and assigned patent number 9,704,951. Our paper titlted " Direct Electrical Probing of Periodic Modulation of Zinc-Dopant Distributions in Planar Gallium Arsenide Nanowires ," has been accepted by ACS Nano ! In this work, using nanoscale resolution microscopies including MIM and IR-SNOM, we provided unambiguous evidence that Zn dopants are preferentially accumulated at the twin-plane boundaries in planar GaAs p-n junction nanowires. Congrats, Wonsik, Eric, and all contributing authors! Our paper titlted " Scaling the Aspect Ratio of Nanoscale Closely-Packed Silicon Vias by MacEtch: Kinetics of Carrier Generation and Mass Transport ," has been accepted by Advanced Functional Materials ! This work represents significant advancement in pushing the potentially disruptive MacEtch (metal-assisted chemical etching) technology towards yet another technically important frontier - small via arrays, while providing in-d...