Anton Persson is a postdoctoral researcher in the Electrical Engineering Department at Stanford University, supervised by Professor Eric Pop. Prior to joining Stanford, he received his PhD in Electrical Engineering from Lund University, Sweden, in 2023 and his M.Sc. in Engineering Physics from Chalmers University of Technology, Sweden, in 2018. At Stanford, he researches emerging memristor technologies for in-memory computing applications, including phase change materials and ferroelectrics integrated onto 2D-materials.
Doctor of Philosophy, Lunds Universitet (2023)
PhD, Lund University, Electrical Engineering (2023)
M.Sc., Chalmers University of Technology, Engineering Physics (2018)
Eric Pop, Postdoctoral Faculty Sponsor
Reconfigurable signal modulation in a ferroelectric tunnel field-effect transistor
2023; 14 (1): 2530
Reconfigurable transistors are an emerging device technology adding new functionalities while lowering the circuit architecture complexity. However, most investigations focus on digital applications. Here, we demonstrate a single vertical nanowire ferroelectric tunnel field-effect transistor (ferro-TFET) that can modulate an input signal with diverse modes including signal transmission, phase shift, frequency doubling, and mixing with significant suppression of undesired harmonics for reconfigurable analogue applications. We realize this by a heterostructure design in which a gate/source overlapped channel enables nearly perfect parabolic transfer characteristics with robust negative transconductance. By using a ferroelectric gate oxide, our ferro-TFET is non-volatilely reconfigurable, enabling various modes of signal modulation. The ferro-TFET shows merits of reconfigurability, reduced footprint, and low supply voltage for signal modulation. This work provides the possibility for monolithic integration of both steep-slope TFETs and reconfigurable ferro-TFETs towards high-density, energy-efficient, and multifunctional digital/analogue hybrid circuits.
View details for DOI 10.1038/s41467-023-38242-w
View details for Web of Science ID 001025174300001
View details for PubMedID 37137907
View details for PubMedCentralID PMC10156808
Sensing single domains and individual defects in scaled ferroelectrics
2023; 9 (5): eade7098
Ultra-scaled ferroelectrics are desirable for high-density nonvolatile memories and neuromorphic computing; however, for advanced applications, single domain dynamics and defect behavior need to be understood at scaled geometries. Here, we demonstrate the integration of a ferroelectric gate stack on a heterostructure tunnel field-effect transistor (TFET) with subthermionic operation. On the basis of the ultrashort effective channel created by the band-to-band tunneling process, the localized potential variations induced by single domains and individual defects are sensed without physical gate-length scaling required for conventional transistors. We electrically measure abrupt threshold voltage shifts and quantify the appearance of new individual defects activated by the ferroelectric switching. Our results show that ferroelectric films can be integrated on heterostructure devices and indicate that the intrinsic electrostatic control within ferroelectric TFETs provides the opportunity for ultrasensitive scale-free detection of single domains and defects in ultra-scaled ferroelectrics. Our approach opens a previously unidentified path for investigating the ultimate scaling limits of ferroelectronics.
View details for DOI 10.1126/sciadv.ade7098
View details for Web of Science ID 000960602300017
View details for PubMedID 36735784
View details for PubMedCentralID PMC9897661
Ferroelectric-Antiferroelectric Transition of Hf1-XZrXO2 on Indium Arsenide with Enhanced Ferroelectric Characteristics for Hf0.2Zr0.8O2
ACS APPLIED ELECTRONIC MATERIALS
2022; 4 (12): 6357-6363
The ferroelectric (FE)-antiferroelectric (AFE) transition in Hf1-x Zr x O2 (HZO) is for the first time shown in a metal-ferroelectric-semiconductor (MFS) stack based on the III-V material InAs. As InAs displays excellent electron mobility and a narrow band gap, the integration of ferroelectric thin films for nonvolatile operations is highly relevant for future electronic devices and motivates further research on ferroelectric integration. When increasing the Zr fraction x from 0.5 to 1, the stack permittivity increases as expected, and the transition from FE to AFE-like behavior is observed by polarization and current-voltage characteristics. At x = 0.8 the polarization of the InAs-based stacks shows a larger FE-contribution as a more open hysteresis compared to both literature and reference metal-ferroelectric-metal (MFM) devices. By field-cycling the devices, the switching domains are studied as a function of the cycle number, showing that the difference in FE-AFE contributions for MFM and MFS devices is stable over switching and not an effect of wake-up. The FE contribution of the switching can be accessed by successively lowering the bias voltage in a proposed pulse train. The possibility of enhanced nonvolatility in Zr-rich HZO is relevant for device stacks that would benefit from an increase in permittivity and a lower operating voltage. Additionally, an interfacial layer (IL) is introduced between the HZO film and the InAs substrate. The interfacial quality is investigated as frequency-dependent capacitive dispersion, showing little change for varying ZrO2 concentrations and with or without included IL. This suggests material processing that is independently limiting the interfacial quality. Improved endurance of the InAs-Hf1-x Zr x O2 devices with x = 0.8 was also observed compared to x = 0.5, with further improvement with the additional IL for Zr-rich HZO on InAs.
View details for DOI 10.1021/acsaelm.2c01483
View details for Web of Science ID 000898905900001
View details for PubMedID 36588621
View details for PubMedCentralID PMC9798826
- Improved Endurance of Ferroelectric HfxZr1-xO2 Integrated on InAs Using Millisecond Annealing ADVANCED MATERIALS INTERFACES 2022; 9 (27)
- As-deposited ferroelectric HZO on a III-V semiconductor APPLIED PHYSICS LETTERS 2022; 121 (1)
- Integration of Ferroelectric HfxZr1-xO2 on Vertical III-V Nanowire Gate-All-Around FETs on Silicon IEEE ELECTRON DEVICE LETTERS 2022; 43 (6): 854-857
- Top Electrode Engineering for Freedom in Design and Implementation of Ferroelectric Tunnel Junctions Based on Hf1-xZrxO2 ACS APPLIED ELECTRONIC MATERIALS 2022; 4 (3): 1002-1009
Effects of TiN Top Electrode Texturing on Ferroelectricity in Hf1-xZrxO2
ACS APPLIED MATERIALS & INTERFACES
2021; 13 (9): 11089-11095
Ferroelectric memories based on hafnium oxide are an attractive alternative to conventional memory technologies due to their scalability and energy efficiency. However, there are still many open questions regarding the optimal material stack and processing conditions for reliable device performance. Here, we report on the impact of the sputtering process conditions of the commonly used TiN top electrode on the ferroelectric properties of Hf1-xZrxO2. By manipulating the deposition pressure and chemistry, we control the preferential orientation of the TiN grains between (111) and (002). We observe that (111) textured TiN is superior to (002) texturing for achieving high remanent polarization (Pr). Furthermore, we find that additional nitrogen supply during TiN deposition leads to >5× greater endurance, possibly by limiting the scavenging of oxygen from the Hf1-xZrxO2 film. These results help explain the large Pr variation reported in the literature for Hf1-xZrxO2/TiN and highlights the necessity of tuning the top electrode of the ferroelectric stack for successful device implementation.
View details for DOI 10.1021/acsami.1c01734
View details for Web of Science ID 000629054100040
View details for PubMedID 33625827
View details for PubMedCentralID PMC8027987
- A method for estimating defects in ferroelectric thin film MOSCAPs APPLIED PHYSICS LETTERS 2020; 117 (24)
- Reduced annealing temperature for ferroelectric HZO on InAs with enhanced polarization APPLIED PHYSICS LETTERS 2020; 116 (6)
Multidimensional Hybridization of Dark Surface Plasmons
2017; 11 (4): 4265-4274
Synthetic three-dimensional (3D) nanoarchitectures are providing more control over light-matter interactions and rapidly progressing photonic-based technology. These applications often utilize the strong synergy between electromagnetic fields and surface plasmons (SPs) in metallic nanostructures. However, many of the SP interactions hosted by complex 3D nanostructures are poorly understood because they involve dark hybridized states that are typically undetectable with far-field optical spectroscopy. Here, we use experimental and theoretical electron energy loss spectroscopy to elucidate dark SPs and their interactions in layered metal-insulator-metal disc nanostructures. We go beyond the established dipole SP hybridization analysis by measuring breathing and multipolar SP hybridization. In addition, we reveal multidimensional SP hybridization that simultaneously utilizes in-plane and out-of-plane SP coupling. Near-field classic electrodynamics calculations provide excellent agreement with all experiments. These results advance the fundamental understanding of SP hybridization in 3D nanostructures and provide avenues to further tune the interaction between electromagnetic fields and matter.
View details for DOI 10.1021/acsnano.7b01318
View details for Web of Science ID 000400233200088
View details for PubMedID 28350962