Preface to Special Topic on Integrated Circuits, Technologies and Applications

This Special Topic of the Journal of Semiconductors(JoS)features expanded versions of key articles presented at the 2023 IEEE International Conference on Integrated Circuits Technologies and Applications(ICTA),which was held in Hefei,Anhui,China,from October 27 to 29,2023.IEEE ICTA is an IEEE flagship conference in the field of integrated circuits(IC)in China,which provides a communication platform for sharing the state-of-the-art techniques from experts in the field of ICs.Among the 93 papers presented at ICTA 2023,the Technical Program Committee and the Award Committee have selected 4 high-quality articles to recommend to the Special Topic of JoS,covering a wide range of technical fields,including one paper on RF ICs,two papers on Analog ICs and one paper on Wireline ICs.

Industry-Oriented Detection Method of PCBA Defects Using Semantic Segmentation Models

Automated optical inspection(AOI)is a significant process in printed circuit board assembly(PCBA)production lines which aims to detect tiny defects in PCBAs.Existing AOI equipment has several deficiencies including low throughput,large computation cost,high latency,and poor flexibility,which limits the efficiency of online PCBA inspection.In this paper,a novel PCBA defect detection method based on a lightweight deep convolution neural network is proposed.In this method,the semantic segmentation model is combined with a rule-based defect recognition algorithm to build up a defect detection frame-work.To improve the performance of the model,extensive real PCBA images are collected from production lines as datasets.Some optimization methods have been applied in the model according to production demand and enable integration in lightweight computing devices.Experiment results show that the production line using our method realizes a throughput more than three times higher than traditional methods.Our method can be integrated into a lightweight inference system and pro-mote the flexibility of AOI.The proposed method builds up a general paradigm and excellent example for model design and optimization oriented towards industrial requirements.

The Roadmap of 2D Materials and Devices Toward Chips

Due to the constraints imposed by physical effects and performance degra certain limitations in sustaining the advancement of Moore’s law.Two-dimensional(2D)materials have emerged as highly promising candidates for the post-Moore era,offering significant potential in domains such as integrated circuits and next-generation computing.Here,in this review,the progress of 2D semiconductors in process engineering and various electronic applications are summarized.A careful introduction of material synthesis,transistor engineering focused on device configuration,dielectric engineering,contact engineering,and material integration are given first.Then 2D transistors for certain electronic applications including digital and analog circuits,heterogeneous integration chips,and sensing circuits are discussed.Moreover,several promising applications(artificial intelligence chips and quantum chips)based on specific mechanism devices are introduced.Finally,the challenges for 2D materials encountered in achieving circuit-level or system-level applications are analyzed,and potential development pathways or roadmaps are further speculated and outlooked.

Oscillation of Dzyaloshinskii–Moriya interaction driven by weak electric fields

Dzyaloshinskii–Moriya interaction(DMI) is under extensive investigation considering its crucial status in chiral magnetic orders, such as Néel-type domain wall(DW) and skyrmions. It has been reported that the interfacial DMI originating from Rashba spin–orbit coupling(SOC) can be linearly tuned with strong external electric fields. In this work, we experimentally demonstrate that the strength of DMI exhibits rapid fluctuations, ranging from 10% to 30% of its original value, as a function of applied electric fields in Pt/Co/MgO heterostructures within the small field regime(< 10-2V/nm). Brillouin light scattering(BLS) experiments have been performed to measure DMI, and first-principles calculations show agreement with this observation, which can be explained by the variation in orbital hybridization at the Co/MgO interface in response to the weak electric fields. Our results on voltage control of DMI(VCDMI) suggest that research related to the voltage control of magnetic anisotropy for spin–orbit torque or the motion control of skyrmions might also have to consider the role of the external electric field on DMI as small voltages are generally used for the magnetoresistance detection.

Angular and planar transport properties of antiferromagnetic V_(5)S_(8)

Systemically angular and planar transport investigations are performed in layered antiferromagnetic(AF)V_(5)S_(8).In this AF system,obvious anomalous Hall effect(AHE)is observed with a large Hall angle of 0.1 compared to that in ferromagnetic(FM)system.It can persist to the temperatures above AF transition and exhibit strong angular field dependence.The phase diagram reveals various magnetic states by rotating the applied field.By analyzing the anisotropic transport behavior,magnon contributions are revealed and exhibit obvious angular dependence with a spin-flop vanishing line.The observed prominent planar Hall effect and anisotropic magnetoresisitivity exhibit two-fold systematical angular dependent oscillations.These behaviors are attributed to the scattering from spin–orbital coupling instead of nontrivial topological origin.Our results reveal anisotropic interactions of magnetism and electron in V5S8,suggesting potential opportunities for the AF spintronic sensor and devices.

Soft Electronics for Health Monitoring Assisted by Machine Learning

Due to the development of the novel materials,the past two decades have witnessed the rapid advances of soft electronics.The soft electronics have huge potential in the physical sign monitoring and health care.One of the important advantages of soft electronics is forming good interface with skin,which can increase the user scale and improve the signal quality.Therefore,it is easy to build the specific dataset,which is important to improve the performance of machine learning algorithm.At the same time,with the assistance of machine learning algorithm,the soft electronics have become more and more intelligent to realize real-time analysis and diagnosis.The soft electronics and machining learning algorithms complement each other very well.It is indubitable that the soft electronics will bring us to a healthier and more intelligent world in the near future.Therefore,in this review,we will give a careful introduction about the new soft material,physiological signal detected by soft devices,and the soft devices assisted by machine learning algorithm.Some soft materials will be discussed such as two-dimensional material,carbon nanotube,nanowire,nanomesh,and hydrogel.Then,soft sensors will be discussed according to the physiological signal types(pulse,respiration,human motion,intraocular pressure,phonation,etc.).After that,the soft electronics assisted by various algorithms will be reviewed,including some classical algorithms and powerful neural network algorithms.Especially,the soft device assisted by neural network will be introduced carefully.Finally,the outlook,challenge,and conclusion of soft system powered by machine learning algorithm will be discussed.

Record-Breaking Frequency of 44 GHz Based on the Higher Order Mode of Surface Acoustic Waves with LiNbO_(3)/SiO_(2)/SiC Heterostructures

Surface acoustic wave (SAW) technology has been extensively explored for wireless communication, sensors, microfluidics, photonics, and quantum information processing. However, due to fabrication issues, the frequencies of SAW devices are typically limited to within a few gigahertz, which severely restricts their applications in 5G communication, precision sensing, photonics, and quantum control. To solve this critical problem, we propose a hybrid strategy that integrates a nanomanufacturing process (i.e., nanolithography) with a LiNbO_(3)/SiO_(2)/SiC heterostructure and successfully achieve a record-breaking frequency of about 44 GHz for SAW devices, in addition to large electromechanical coupling coefficients of up to 15.7%. We perform a theoretical analysis and identify the guided higher order wave modes generated on these slow-on-fast SAW platforms. To demonstrate the superior sensing performance of the proposed ultra-high-frequency SAW platforms, we perform micro-mass sensing and obtain an extremely high sensitivity of approximately 33151.9 MHz·mm2·μg−1, which is about 1011 times higher than that of a conventional quartz crystal microbalance (QCM) and about 4000 times higher than that of a conventional SAW device with a frequency of 978 MHz.

Demonstration of a manufacturable SOT-MRAM multiplexer array towards industrial applications

We have successfully demonstrated a 1 Kb spin-orbit torque(SOT)magnetic random-access memory(MRAM)multiplexer(MUX)array with remarkable performance.The 1 Kb MUX array exhibits an in-die function yield of over 99.6%.Additionally,it provides a sufficient readout window,with a TMR/RP_sigma%value of 21.4.Moreover,the SOT magnetic tunnel junctions(MTJs)in the array show write error rates as low as 10^(-6)without any ballooning effects or back-hopping behaviors,ensuring the write stability and reliability.This array achieves write operations in 20 ns and 1.2 V for an industrial-level temperature range from-40 to 125℃.Overall,the demonstrated array shows competitive specifications compared to the state-of-the-art works.Our work paves the way for the industrial-scale production of SOT-MRAM,moving this technology beyond R&D and towards widespread adoption.

Suppression and compensation effect of oxygen on the behavior of heavily boron-doped diamond films

This work investigates the suppression and compensation effect of oxygen on the behaviors and characteristics of heavily boron-doped microwave plasma chemical vapor deposition(MPCVD)diamond films.The suppression effect of oxygen on boron incorporation is observed by an improvement in crystal quality when oxygen is added during the diamond doping process.A relatively low hole concentration is expected and verified by Hall effect measurements due to the compensation effect of oxygen as a deep donor in diamond.A low acceptor concentration,high compensation donor concentration and relatively larger acceptor ionization energy are then induced by the incorporation of oxygen;however,a heavily boron-doped diamond film with high crystal quality can also be expected.The formation of an oxygen–boron complex structure instead of oxygen substitution,as indicated by the results of x-ray photoelectron spectroscopy,is suggested to be more responsible for the observed enhanced compensation effect due to its predicted low formation energy.Meanwhile,density functional theory calculations show that the boron–oxygen complex structure is easily formed in diamond with a formation energy of-0.83 eV.This work provides a comprehensive understanding of oxygen compensation in heavily boron-doped diamond.

Ferroelectricity of hafnium oxide-based materials:Current status and future prospects from physical mechanisms to device applications

The finding of the robust ferroelectricity in HfO_(2)-based thin films is fantastic from the view point of both the fundamentals and the applications.In this review article,the current research status of the future prospects for the ferroelectric HfO_(2)-based thin films and devices are presented from fundamentals to applications.The related issues are discussed,which include:1)The ferroelectric characteristics observed in HfO_(2)-based films and devices associated with the factors of dopant,strain,interface,thickness,defect,fabrication condition,and more;2)physical understanding on the observed ferroelectric behaviors by the density functional theory(DFT)-based theory calculations;3)the characterizations of microscopic and macroscopic features by transmission electron microscopes-based and electrical properties-based techniques;4)modeling and simulations,5)the performance optimizations,and 6)the applications of some ferroelectric-based devices such as ferroelectric random access memory,ferroelectric-based field effect transistors,and the ferroelectric tunnel junction for the novel information processing systems.

A family of flexible two-dimensional semiconductors:MgMX2Y6(M=Ti/Zr/Hf;X=Si/Ge;Y=S/Se/Te)

Inspired by the recently predicted 2D MX_(2)Y_(6)(M=metal element;X=Si/Ge/Sn;Y=S/Se/Te),we explore the possible applications of alkaline earth metal(using magnesium as example)in this family based on the idea of element replacement and valence electron balance.Herein,we report a new family of 2D quaternary compounds,namely MgMX_(2)Y_(6)(M=Ti/Zr/Hf;X=Si/Ge;Y=S/Se/Te)monolayers,with superior kinetic,thermodynamic and mechanical stability.In addition,our results indicate that MgMX_(2)Y_(6)monolayers are all indirect band gap semiconductors with band gap values ranging from 0.870 to 2.500 eV.Moreover,the band edges and optical properties of 2D MgMX_(2)Y_(6)are suitable for constructing multifunctional optoelectronic devices.Furthermore,for comparison,the mechanical,electronic and optical properties of In_(2)X_(2)Y_(6)monolayers have been discussed in detail.The success of introducing Mg into the 2D MX_(2)Y_(6)family indicates that more potential materials,such as Caand Sr-based 2D MX_(2)Y_(6)monolayers,may be discovered in the future.Therefore,this work not only broadens the existing family of 2D semiconductors,but it also provides beneficial results for the future.

A review of automatic detection of epilepsy based on EEG signals

Epilepsy is a common neurological disorder that occurs at all ages.Epilepsy not only brings physical pain to patients,but also brings a huge burden to the lives of patients and their families.At present,epilepsy detection is still achieved through the observation of electroencephalography(EEG)by medical staff.However,this process takes a long time and consumes energy,which will create a huge workload to medical staff.Therefore,it is particularly important to realize the automatic detection of epilepsy.This paper introduces,in detail,the overall framework of EEG-based automatic epilepsy identification and the typical methods involved in each step.Aiming at the core modules,that is,signal acquisition analog front end(AFE),feature extraction and classifier selection,method summary and theoretical explanation are carried out.Finally,the future research directions in the field of automatic detection of epilepsy are prospected.

Low working loss Si/4H-SiC heterojunction MOSFET with analysis of the gate-controlled tunneling effect

A silicon (Si)/silicon carbide (4H-SiC) heterojunction double-trench metal-oxide-semiconductor field effect transistor (MOSFET) (HDT-MOS) with the gate-controlled tunneling effect is proposed for the first time based on simulations. In this structure, the channel regions are made of Si to take advantage of its high channel mobility and carrier density. The voltage-withstanding region is made of 4H-SiC so that HDT-MOS has a high breakdown voltage (BV) similar to pure 4H-SiC double-trench MOSFETs (DT-MOSs). The gate-controlled tunneling effect indicates that the gate voltage (V_(G)) has a remarkable influence on the tunneling current of the heterojunction. The accumulation layer formed with positive VG can reduce the width of the Si/SiC heterointerface barrier, similar to the heavily doped region in an Ohmic contact. This narrower barrier is easier for electrons to tunnel through, resulting in a lower heterointerface resistance. Thus, with similar BV (approximately 1770 V), the specific on-state resistance (R_(ON-SP)) of HDT-MOS is reduced by 0.77 mΩ·cm^(2) compared with that of DT-MOS. The gate-to-drain charge (Q_(GD)) and switching loss of HDT-MOS are 52.14% and 22.59% lower than those of DT-MOS, respectively, due to the lower gate platform voltage (V_(GP)) and the corresponding smaller variation (ΔV_(GP)). The figure of merit (Q_(GD)×R_(ON-SP)) of HDT-MOS decreases by 61.25%. Moreover, the heterointerface charges can reduce RON-SP of HDT-MOS due to trap-assisted tunneling while the heterointerface traps show the opposite effect. Therefore, the HDT-MOS structure can significantly reduce the working loss of SiC MOSFET, leading to a lower temperature rise when the devices are applied in the system.

Improving the films quality of Sn-based perovskites through additive treatment for high-performance light-emitting diodes

Hybrid lead halide perovskites have received great attention in the field of light-emitting diodes(LEDs)owing to their excellent optoelectronic properties,low cost,and high color purity.To data,the external quantum efficiency(EQE)of lead halide perovskites LEDs has been reported to exceed 20%[1].Even so,the toxicity of conventional lead has cast a gloomy shadow over their further application.

Topological magnetotransport and electrical switching of sputtered antiferromagnetic Ir_(20)Mn_(80)

Topological magnetotransport in non-collinear antiferromagnets has attracted extensive attention due to the exotic phenomena such as large anomalous Hall effect(AHE),magnetic spin Hall effect,and chiral anomaly.The materials exhibiting topological antiferromagnetic physics are typically limited in special Mn_3X family such as Mn_3Sn and Mn_3Ge.Exploring the topological magnetotransport in common antiferromagnetic materials widely used in spintronics will not only enrich the platforms for investigating the non-collinear antiferromagnetic physics,but also have great importance for driving the nontrivial topological properties towards practical applications.Here,we report remarkable AHE,anisotropic and negative parallel magnetoresistance in the magnetron-sputtered Ir_(20)Mn_(80)antiferromagnet,which is one of the most widely used antiferromagnetic materials in industrial spintronics.The ab initio calculations suggest that the Ir_4Mn_(16)(IrMn_4)or Mn_3Ir nanocrystals hold nontrivial electronic band structures,which may contribute to the observed intriguing magnetotransport properties in the Ir_(20)Mn_(80).Further,we demonstrate the spin–orbit torque switching of the antiferromagnetic Ir_(20)Mn_(80)by the spin Hall current of Pt.The presented results highlight a great potential of the magnetron-sputtered Ir_(20)Mn_(80)film for exploring the topological antiferromagnet-based physics and spintronics applications.

Tissue Microstructure Estimation of SANDI Based on Deep Network

Diffusion magnetic resonance imaging(dMRI)is a noninvasive method to capture the anisotropic pattern of water displacement in the neuronal tissue.The soma and neurite density imaging(SANDI)model introduced soma size and density to biophysical model for the first time.In addition to neurite density,it can achieve their joint estimation non-invasively using dMRI.In the traditional method,parameters of the SANDI are estimated in a maximum likelihood frame-work,where the nonlinear model fitting is computationally intensive.Also,the present methods require a large number of diffusion gradients.Efficient and accurate algorithms for tissue microstructure estimation of SANDI is still a challenge currently.Consequently,we introduce deep learning method for tissue microstructure estimation of the SANDI model.The model comprises two functional components.The first component produces the sparse representation of diffusion sig-nals of input patches.The second component computes tissue microstructure from the sparse repre-sentation given by the first component.The deep network can produce not only tissue microstruc-ture estimates but also the uncertainty of the estimates with a reduced number of diffusion gradi-ents.Then,multiple deep networks are trained and their results are fused for the final prediction of tissue microstructure and uncertainty quantification.The deep network was evaluated on the MGH Connectome Diffusion Microstructure Dataset.Results indicate that our approach outperforms the traditional methods in terms of estimation accuracy.

Impact of low-dose radiation on nitrided lateral 4H-SiC MOSFETs and the related mechanisms

Lateral type n-channel 4H-SiC metal–oxide–semiconductor field effect transistors(MOSFETs),fabricated using a current industrial process,are irradiated with gamma rays at different irradiation doses in this paper to carry out a profound study on the generation mechanism of radiation-induced interface traps and oxide trapped charges.Electrical parameters(e.g.,threshold voltage,subthreshold swing and channel mobility)of the device before and after irradiation are investigated,and the influence of the channel orientation([1100]and[1120])on the radiation effect is discussed for the first time.A positive threshold voltage shift is observed at very low irradiation doses(<100 krad(Si));the threshold voltage then shifts negatively as the dose increases.It is found that the dependence of interface trap generation on the radiation dose is not the same for doses below and above 100 krad.For irradiation doses<100 krad,the radiation-induced interface traps with relatively high generation speeds dominate the competition with radiation-induced oxide trapped charges,contributing to the positive threshold voltage shift correspondingly.All these results provide additional insight into the radiation-induced charge trapping mechanism in the SiO_(2)/SiC interface.

Multi-Mode Bus Coupling Architecture of Superconducting Quantum Processor

Resonators in circuit quantum electrodynamics systems naturally carry multiple modes, which may have non-negligible influence on qubit parameters and device performance. While new theories and techniques are under investigation to deal with the multi-mode effects in circuit quantum electrodynamics systems, researchers have proposed novel engineering designs featuring multi-mode resonators to achieve enhanced functionalities of superconducting quantum processors. Here, we propose multi-mode bus coupling architecture, in which superconducting qubits are coupled to multiple bus resonators to gain larger coupling strength. Applications of multi-mode bus couplers can be helpful for improving i SWAP gate fidelity and gate speed beyond the limit of single-mode scenario. The proposed multi-mode bus coupling architecture is compatible with a scalable variation of the traditional bus coupling architecture. It opens up new possibilities for realization of scalable superconducting quantum computation with circuit quantum electrodynamics systems.

Temperature dependence of single-event transients in SiGe heterojunction bipolar transistors for cryogenic applications

We experimentally demonstrate that the dominant mechanism of single-event transients in silicon-germanium heterojunction bipolar transistors(SiGe HBTs)can change with decreasing temperature from+20℃to-180℃.This is accomplished by using a new well-designed cryogenic experimental system suitable for a pulsed-laser platform.Firstly,when the temperature drops from+20℃to-140℃,the increased carrier mobility drives a slight increase in transient amplitude.However,as the temperature decreases further below-140℃,the carrier freeze-out brings about an inflection point,which means the transient amplitude will decrease at cryogenic temperatures.To better understand this result,we analytically calculate the ionization rates of various dopants at different temperatures based on Altermatt's new incomplete ionization model.The parasitic resistivities with temperature on the charge-collection pathway are extracted by a two-dimensional(2D)TCAD process simulation.In addition,we investigate the impact of temperature on the novel electron-injection process from emitter to base under different bias conditions.The increase of the emitter-base junction's barrier height at low temperatures could suppress this electron-injection phenomenon.We have also optimized the built-in voltage equations of a high current compact model(HICUM)by introducing the impact of incomplete ionization.The present results and methods could provide a new reference for effective evaluation of single-event effects in bipolar transistors and circuits at cryogenic temperatures,and could provide a new evidence of the potential of SiGe technology in applications in extreme cryogenic environments.

Asymmetric scattering behaviors of spin wave dependent on magnetic vortex chirality

We investigate asymmetric spin wave scattering behaviors caused by vortex chirality in a cross-shaped ferromagnetic system by using the micromagnetic simulations.In the system,four scattering behaviors are found:(i)asymmetric skew scattering,depending on the polarity of vortex core,(ii)back scattering(reflection),depending on the vortex core stiffness,(iii)side deflection scattering,depending on structural symmetry of the vortex circulation,and(iv)geometrical scattering,depending on waveguide structure.The first and second scattering behaviors are attributed to nonlinear topological magnon spin Hall effect related to magnon spin-transfer torque effect,which has value for magnonic exploration and application.