Silicon Nanowire Field-effect Transistors Research Articles

Complementary Photo‐Synapses: Complementary Photo‐Synapses Based on Light‐Stimulated Porphyrin‐Coated Silicon Nanowires Field‐Effect Transistors (LPSNFET) (Small 30/2021)

In article number 2101434, Ming Li and co-workers propose a CMOS-compatible Light-stimulated Porphyrin-coated Silicon Nanowire Field Effect Transistor (LPSNFET) to form the complementary photo-synapses with only two CMOS-like transistors. LPSNFET exhibits five-fold improvement in photo sensitivity compared to the bare silicon nanowire devices. Complementarily behaviors can be realized by modulating SiNW/porphyrin interface, and the CMOS compatibility provides a potential application in future large scale in-sensor computing.

On the Operation Modes of Dual-Gate Reconfigurable Nanowire Transistors

We investigate the operation of dual-gate reconfigurable field-effect transistor (RFET) in the programgate at drain (PGAD) and program-gate at source (PGAS) configurations. To this end, dual-gate silicon nanowire (SiNW) FETs are fabricated based on anisotropic wet chemical silicon etching and nickel silicidation yielding silicide-SiNW Schottky junctions at source and drain. Whereas in PGAD-configuration ambipolar operation is suppressed, switching is deteriorated due to the injection through a Schottky-barrier. Operating the RFET in PGAS configuration yields a switching behavior close to a conventional MOSFET. This, howewer, needs to be traded off against strongly non-linear output characteristics for small bias.

Complementary Photo-Synapses Based on Light-Stimulated Porphyrin-Coated Silicon Nanowires Field-Effect Transistors (LPSNFET).

Neuromorphic computing has emerged as the high-energy-efficiency and intelligent solution for processing sensory data. As a potential alternative to neuromorphic computing, photo-excited synaptic systems can integrate the functions of optoelectronic sensing and synaptic computing to realize the low-power and high-performance visual perception. However, one major challenge in high-efficient photo-excited synaptic system is to realize the complementarily enhanced and inhibited synaptic behaviors with small hardware cost as possible. Another challenge is to fabricate the photo-synapse devices with complementary metal oxide semiconductor (CMOS)-compatible process to achieve high enough integration density for practical application. Here, a CMOS-compatible Light-stimulated Porphyrin-coated Silicon Nanowire Field Effect Transistor (LPSNFET) technology is proposed and developed to form the complementary photo-synapses with only two CMOS-like transistors. LPSNFET exhibits fivefold improvement in photo-sensitivity compared to the bare silicon nanowire (SiNW) devices, and can still show obvious responses when incident illumination power is as low as 0.1 mW cm-2 . Moreover,itenables tunable dynamic synaptic plasticity and versatile synaptic functions. Especially, the complementarily enhanced and inhibited behaviors can be realized by modulating SiNW/porphyrin interface via simply changing the MOS type of LPSNFET, which acts like the photonic counterpart of CMOS technology to provide the basic brick for building complex neuromorphic circuits efficiently and economically. Finally, the CMOS process compatibility of LPSNFET provides potential application in future large scale in-sensor computing.

Highly Sensitive and Selective Sodium Ion Sensor Based on Silicon Nanowire Dual Gate Field-Effect Transistor

In this study, a highly sensitive and selective sodium ion sensor consisting of a dual-gate (DG) structured silicon nanowire (SiNW) field-effect transistor (FET) as the transducer and a sodium-selective membrane extended gate (EG) as the sensing unit was developed. The SiNW channel DG FET was fabricated through the dry etching of the silicon-on-insulator substrate by using electrospun polyvinylpyrrolidone nanofibers as a template for the SiNW pattern transfer. The selectivity and sensitivity of sodium to other ions were verified by constructing a sodium ion sensor, wherein the EG was electrically connected to the SiNW channel DG FET with a sodium-selective membrane. An extremely high sensitivity of 1464.66 mV/dec was obtained for a NaCl solution. The low sensitivities of the SiNW channel FET-based sodium ion sensor to CaCl2, KCl, and pH buffer solutions demonstrated its excellent selectivity. The reliability and stability of the sodium ion sensor were verified under non-ideal behaviors by analyzing the hysteresis and drift. Therefore, the SiNW channel DG FET-based sodium ion sensor, which comprises a sodium-selective membrane EG, can be applied to accurately detect sodium ions in the analyses of sweat or blood.

Design, optimization, and analysis of Si and GaN nanowire FETs for 3 nm technology

Nanowires, due to their unique properties, are emerging as the building blocks of the next-generation electronics industry and will play a critical role in both low- and high-performance circuits and systems. This work presents the design, optimization, and analysis of a silicon (Si) and gallium-nitride nanowire field-effect transistor (GaN NW FET) to evaluate its performance at the ultra-scaled device dimensions required for GaN NW FETs in the electronics industry in order to increase the packing density and overall performance of the device. The analysis was carried out using self-consistent Poisson and Schrödinger equations based on a non-equilibrium Green function (NEGF) approach using Silvaco ATLAS. A reduction of 84.07% in the ‘off’ current was observed for the GaN NW FET, as compared to its Si counterparts, which reveals the requirement for a GaN NW FET at extremely scaled dimensions for ‘off’ state leakage suppression. Optimization of the electrostatic control mechanism, gate oxide, gate oxide thickness (t ox), and metal work functions (φ ms) was performed using quantum simulation models to investigate the influence of these parameters on the device performance. A way of improving the I on/I off ratio of the device has been reported using metal contact length and width variations. A 40% reduction in the subthreshold swing value offers improvements in the electrostatic control I on/I off ratio of ∼104, ∼105, and 102 due to the respective optimizations of the metal contact length (L c), metal contact width (W c), and metal work function (φ ms) of the GaN NW FET, compared to the Si NW FET, thus making the GaN NW FET an intriguing option for digital electronics applications. A comparison of the semi-classical (Drift Diffusion_Mode Space) and quantum (Non-Equilibrium Green Function_Mode Space) transport models was also carried out to reveal the importance of the accuracy of these models at such low dimensions. This optimization and analysis will help us to further improve the performance of experimental work and will act as a reference for the same. This study reveals the performance advantages of the GaN NW FET over the Si NW FET for transistor applications in the electronics industry and can serve as a reference point for the researchers working in this area. To the best of our knowledge, no such comparison has been reported so far for Si and GaN NW FETs using 3 nm technology.

Fabrication of Graphoepitaxial Gate-All-Around Si Circuitry Patterned Nanowire Arrays Using Block Copolymer Assisted Hard Mask Approach.

We demonstrate the fabrication of sub-20 nm gate-all-around silicon (Si) nanowire field effect transistor structures using self-assembly. To create nanopatterned Si feature arrays, a block-copolymer-assisted hard mask approach was utilized using a topographically patterned substrate with well-defined Si3N4 features for graphoepitaxially alignment of the self-assembled patterns. Microphase-separated long-range ordered polystyrene-b-poly(ethylene oxide) (PS-b-PEO) block-copolymer-derived dot and line nanopatterns were achieved by a thermo-solvent approach within the substrate topographically defined channels of various widths and lengths. Solvent annealing parameters (temperature, annealing time, etc.) were varied to achieve the desired patterns. The BCP structures were modified by anhydrous ethanol to facilitate insertion of iron oxide features within the graphoepitaxial trenches that maintained the parent BCP arrangements. Vertical and horizontal ordered Si nanowire structures within trenches were fabricated using the iron oxide features as hard masks in an inductively coupled plasma (ICP) etch process. Cross-sectional micrographs depict wires of persistent width and flat sidewalls indicating the effectiveness of the mask. The aspect ratios could be varied by varying etch times. The sharp boundaries between the transistor components was also examined through the elemental mapping.

A Theoretical and Simulation Analysis of the Sensitivity of SiNWs-FET Sensors.

Theoretical study and software simulation on the sensitivity of silicon nanowires (SiNWs) field effect transistor (FET) sensors in terms of surface-to-volume ratio, depletion ratio, surface state and lattice quality are carried out. Generally, SiNWs-FET sensors with triangular cross-sections are more sensitive than sensors with circular or square cross-sections. Two main reasons are discussed in this article. Firstly, SiNWs-FET sensors with triangular cross-sections have the largest surface-to-volume ratio and depletion ratio which significantly enhance the sensors’ sensitivity. Secondly, the manufacturing processes of the electron beam lithography (EBL) and chemical vapor deposition (CVD) methods seriously affect the surface state and lattice quality, which eventually influence SiNWs-FET sensors’ sensitivity. In contrast, wet etching and thermal oxidation (WETO) create fewer surface defects and higher quality lattices. Furthermore, the software simulation confirms that SiNWs-FET sensors with triangular cross-sections have better sensitivity than the other two types of SiNWs-FET sensors under the same conditions, consistent with the theoretical analysis. The article fully proved that SiNWs-FET sensors fabricated by the WETO method produced the best sensitivity and it will be widely used in the future.

Terrace-confined guided growth of high-density ultrathin silicon nanowire array for large area electronics

Ultrathin silicon nanowires (SiNWs) are ideal 1D channels to construct high performance nanoelectronics and sensors. We here report on a high-density catalytic growth of orderly ultrathin SiNWs, with diameter down to and narrow NW-to-NW spacing of only ∼80 nm, without the use of high-resolution lithography. This has been accomplished via a terrace-confined strategy, where tiny indium (In) droplets move on sidewall terraces to absorb precoated amorphous Si layer as precursor and produce self-aligned SiNW array. It is found that, under proper parameter control, a tighter terrace-step confinement can help to scale the dimensions of the SiNW array down to the extremes that have not been reported before, while maintaining still a stable guiding growth over complex contours. Prototype SiNW field effect transistors demonstrate a high I on/I off current ratio ∼107, low leakage current of ∼0.3 pA and steep subthreshold swing of 220 mV dec−1. These results highlight the unexplored potential of catalytic growth in advanced nanostructure fabrication that is highly relevant for scalable SiNW logic and sensor applications.

Neuron‐Gated Silicon Nanowire Field Effect Transistors to Follow Single Spike Propagation within Neuronal Network

Silicon nanowire field effect transistors (SiNW‐FETs) provide a local probe for sensing neuronal activity at the subcellular scale, thanks to their nanometer size and ultrahigh sensitivity. The combination with micropatterning or microfluidic techniques to build model neurons networks above SiNW arrays could allow monitoring of spike propagation and tailor specific stimulations, being useful to investigate network communications at multiple scales, such as plasticity or computing processes. This versatile device could be useful in many research areas, including diagnosis, prosthesis, and health security. Herein, SiNW‐based arrays enable to record electrical signals from matured neurons, such as local field potential and unitary spike within ex vivo preparations and hippocampal neurons grown on chip respectively. Furthermore, the ability to guide neurites above the sensor array during 3 weeks of cultures is demonstrated and the propagation of spikes along cells is followed. The SiNW‐FETs are obtained by a top‐down approach with complementary metal oxide semiconductor (CMOS) technology, showing the possibility to implement them at the manufacturing level. These results confirm further the potentiality of the approach to follow spike propagation over large distances and at precise locations along neuronal cells, by providing a multiscale addressing at the nano and mesoscales.

Using breath analysis as a screening tool to detect gastric cancer: A systematic review.

175 Background: In its early stages, gastric cancer symptoms are frequently lacking, resulting in an often late and incurable diagnosis. A non-invasive, cheap, and reliable screening method for gastric cancer could improve outcomes and increase the number of surgically resectable gastric cancers. Breath analysis has emerged as an experimental method of non-invasive screening of gastric cancer and identification of individuals suitable for confirmatory, diagnostic upper gastrointestinal endoscopy. We aimed to evaluate the accuracy and applicability of breath analysis for gastric cancer detection in adults. Methods: This systematic review searched MEDLINE, EMBASE, BIOSIS, CENTRAL, and Compendex until 11 July 2019 for original studies analyzing exhaled breath to detect gastric cancer in patients. Two authors then independently screened the abstracts, titles, and full texts. Summary sensitivity and specificity analyses were obtained using a hierarchical bivariate method. Positive predictive value and number needed to screen (NNS) of breath analysis methods for gastric cancer detection were calculated for each country using gastric cancer prevalence by country obtained from the Global Cancer Observatory. Non-quantitative results were descriptively summarized. Risk of bias was assessed using the QUADAS-2 tool. This study protocol was pre-registered in PROSPERO (CRD42020139422). Results: Twenty studies were included. Together, the studies included 2,976 subjects. The pooled mean age of the subjects in the gastric cancer groups was 60.5 ± 11 years while the pooled mean age for control groups was 55.4 ± 12 years. Within these twenty studies, breath analysis technologies most commonly used were mass spectrometry (MS)-based methods; other methods included volatile organic compound sensors, thermal desorption tubes, and silicon nanowire field effect transistors. Across all included studies, we found and summarized the characteristics of 131 chemical compounds found in the exhaled breath of study subjects. Eleven studies (total n = 1905) involving all technologies reported quantitative results, with sensitivities ranging from 67-100% and specificities from 71-98%. The summary sensitivity across six studies utilizing MS-based breath analysis methods was 85.3% (95% CI: 82-96%); summary specificity was 81.7%. (95% CI: 78-85%). Based on the MS-based values, we estimated that screening with MS-based breath tests could lower the NNS by more than four-fold in the 15 countries with the highest prevalence of gastric cancer. Conclusions: Breath analysis is a promising method for gastric cancer detection with good diagnostic performance and potential to decrease the NNS for endoscopy-based gastric cancer detection. However, due to the heterogeneity of breath analysis technologies, rigorous studies with standardized, reproducible methods are needed to evaluate the clinical applicability of these technologies.

Combination of Aptamer Amplifier and Antigen-Binding Fragment Probe as a Novel Strategy to Improve Detection Limit of Silicon Nanowire Field-Effect Transistor Immunosensors

Detecting proteins at low concentrations in high-ionic-strength conditions by silicon nanowire field-effect transistors (SiNWFETs) is severely hindered due to the weakened signal, primarily caused by screening effects. In this study, aptamer as a signal amplifier, which has already been reported by our group, is integrated into SiNWFET immunosensors employing antigen-binding fragments (Fab) as the receptors to improve its detection limit for the first time. The Fab-SiNWFET immunosensors were developed by immobilizing Fab onto Si surfaces modified with either 3-aminopropyltriethoxysilane (APTES) and glutaraldehyde (GA) (Fab/APTES-SiNWFETs), or mixed self-assembled monolayers (mSAMs) of polyethylene glycol (PEG) and GA (Fab/PEG-SiNWFETs), to detect the rabbit IgG at different concentrations in a high-ionic-strength environment (150 mM Bis-Tris Propane) followed by incubation with R18, an aptamer which can specifically target rabbit IgG, for signal enhancement. Empirical results revealed that the signal produced by the sensors with Fab probes was greatly enhanced compared to the ones with whole antibody (Wab) after detecting similar concentrations of rabbit IgG. The Fab/PEG-SiNWFET immunosensors exhibited an especially improved limit of detection to determine the IgG level down to 1 pg/mL, which has not been achieved by the Wab/PEG-SiNWFET immunosensors.

Silicon Nanowire Parameter Extraction Using DFT and Comparative Performance Analysis of SiNWFET and CNTFET Devices

The performance and scalability of silicon nanowire field-effect transistor (SiNWFET) and carbon nanotube field-effect transistor (CNTFET) with surround gate geometry were studied using such tools as material exploration and design analysis (MedeA) and device modeling and simulation SilvacoTCAD. The SiNWFET and CNTFET with gate-all-around (GAA) structure offer good gate electrostatic control, high On-current and better suppression of short-channel effects with complete encirclement of the device channel. Rather than using the bulk properties of silicon, estimation of properties silicon nanowire (SiNW) was made using MedeA VASP tool based on density functional theory (DFT). In this study, the device input (ID–VGS) and output (ID–VDS) have been analyzed and parameters like threshold voltage, IOn/IOff ratio, drain induced barrier lowering and sub-threshold slope extracted, and comparison is made between SiNWFET and CNTFET devices. The results point towards the DFT-based material parameter estimation to incorporate the quantum effects and use of SiNW/CNT-based GAA structure below 10 nm to meet scaling targets. The results suggest that the SiNWFET and CNTFET device with GAA geometry could be a better alternative to conventional MOSFETs and FinFET for numerous high-performance and low-power device applications.

Impacts of gate length and doping concentrations on the performance of silicon nanowire Field effect Transistor

Early detection of diseases became a big task for early medication. To detect these diseases, sensors with antibody-antigen combinations play important role. From the past several years, one of the prominent sensor structures to obtain the requirement consists of Silicon nanowire. The major impact of Silicon Nanowire Field Effect Transistor (Si-NW FET) structures respond to small change in the gate length and type of silicon material concentration as a gate material. Si-NW material in the range of nano regime, because of their property gate has higher surface to volume ratio. Hence, high surface to volume ratio of Si-NW FETs results better performance for the various sensing applications. For obtaining high surface to volume ratio is challenging due to high in fabrication cost and design constrains. In this paper presents to optimization and improve the performance of Si-NW FET with altering different parameters like gate length and doping concentrations of silicon material. The device is simulated using TCAD software with different gate length and type silicon materials with phosphorous (n-type) and boron (p-type) doping concentrations performance are obtained with drain current (Ids) and compares all the obtained resistivity values and that leads to the better performance of the device.

Rapid indication of the influenza virus using a biosensor based on a silicon nanowire field-effect transistor

Rapid indication of the influenza virus using a biosensor based on a silicon nanowire field-effect transistor

Hardware Security Exploiting Post-CMOS Devices: Fundamental Device Characteristics, State-of-the-Art Countermeasures, Challenges and Roadmap

Emerging nanoelectronic semiconductor devices have been quite promising in enhancing hardware-oriented security and trust. However, implementing hardware security primitives and methodologies requires large area overhead and power consumption. Furthermore, emerging new attack models and vulnerabilities are regularly evolving and cannot be adequately addressed by current CMOS technology. This paper for the first time presents a comprehensive review of numerous post-CMOS technologies based hardware security primitives and methodologies, particularly true random number generators, physically unclonable functions, sidechannel analysis countermeasures, and hardware obfuscation techniques. Various beyond-CMOS device technologies including tunneling FET (TFET), hybrid phase transition FET (HyperFET), carbon nanotube FET (CNTFET), silicon nanowire FET (SiNWFET), symmetrical tunneling FET (SymFET), phase-change memory (PCM), spin-transfer torque magnetic tunnel junction (STT-MTJ), resistive random access memory (RRAM) have been considered in this study. First, the basic principle of operation and unusual characteristics of nanoelectronic devices used for hardware security applications have been extensively discussed. Later, CMOS technology challenges and benefits of emerging nanotechnologies for the design of hardware security primitives and methodologies have been reported. Finally, different analyses have been presented to demonstrate the promising performance of post-CMOS devices over the current CMOS technology in different countermeasures. Additionally, challenges, future directions, and plans have been presented to achieve more research outcomes in this field.

Unexpected phosphorus doping routine of planar silicon nanowires for integrating CMOS logics.

Complementary doping control in silicon nanowire (SiNW) channels is crucial for the construction of high-performance CMOS logics. Though planar in-plane solid-liquid-solid (IPSLS) growth, with an amorphous Si (a-Si) thin film as a precursor, has demonstrated a precise and scalable integration of orderly SiNWs, a complementary and tunable n-type doping has not been accomplished. This has been hindered by the fact that the phosphorus (P) gas dopants will react with the indium (In) catalyst droplet to form insoluble InP precipitates. Nevertheless, we herein report on an unexpected discovery that the P dopants first incorporated into the a-Si matrix can easily diffuse over the In catalyst droplets, without forming an InP compound, and thus reverse continuously the initial p-type SiNWs into an n-type channel. Uniform and efficient doping effects have been confirmed by both atomic probe tomography mapping and the transfer properties of SiNW FETs, which demonstrate a steep subthreshold swing of 105 mV dec-1, an on/off ratio of >107 and an electron mobility of 142 cm2 V-1 s-1. Finally, true CMOS inverters are successfully demonstrated based on the closely-packed SiNW channels of distinct doping polarities, indicating a new convenient and highly efficient doping routine to construct more advanced SiNW logics and sensors.

Comprehensive Understanding of Silicon-Nanowire Field-Effect Transistor Impedimetric Readout for Biomolecular Sensing.

Impedance sensing with silicon nanowire field-effect transistors (SiNW-FETs) shows considerable potential for label-free detection of biomolecules. With this technique, it might be possible to overcome the Debye-screening limitation, a major problem of the classical potentiometric readout. We employed an electronic circuit model in Simulation Program with Integrated Circuit Emphasis (SPICE) for SiNW-FETs to perform impedimetric measurements through SPICE simulations and quantitatively evaluate influences of various device parameters to the transfer function of the devices. Furthermore, we investigated how biomolecule binding to the surface of SiNW-FETs is influencing the impedance spectra. Based on mathematical analysis and simulation results, we proposed methods that could improve the impedimetric readout of SiNW-FET biosensors and make it more explicable.

Silicon Nanowire Field-Effect Transistor as Biosensing Platforms for Post-Translational Modification.

Protein tyrosine sulfation (PTS), a vital post-translational modification, facilitates protein–protein interactions and regulates many physiological and pathological responses. Monitoring PTS has been difficult owing to the instability of sulfated proteins and the lack of a suitable method for detecting the protein sulfate ester. In this study, we combined an in situ PTS system with a high-sensitivity polysilicon nanowire field-effect transistor (pSNWFET)-based sensor to directly monitor PTS formation. A peptide containing the tyrosine sulfation site of P-selectin glycoprotein ligand (PSGL)-1 was immobilized onto the surface of the pSNWFET by using 3-aminopropyltriethoxysilane and glutaraldehyde as linker molecules. A coupled enzyme sulfation system consisting of tyrosylprotein sulfotransferase and phenol sulfotransferase was used to catalyze PTS of the immobilized PSGL-1 peptide. Enzyme-catalyzed sulfation of the immobilized peptide was readily observed through the shift of the drain current–gate voltage curves of the pSNWFET before and after PTS. We expect that this approach can be developed as a next generation biochip for biomedical research and industries.

Utilization of silicon nanowire field-effect transistors for the detection of a cardiac biomarker, cardiac troponin I and their applications involving animal models

This study develops an ultrasensitive electrical device, the silicon nanowire-field effect transistor (SiNW-FET) for detection of cardiac troponin I (cTnI) in obesity induced myocardial injury. The biosensor device utilizes metal–oxide–semiconductor (MOS) compatible top-down methodology for the fabrication process. After fabrication, the surface of the SiNW is modified with the cTnI monoclonal antibody (Mab-cTnI) upon covalent immobilization to capture cTnI antigen. The sensitivity of the device is also examined using cTnI at different concentrations with the lowest detection limit of 0.016 ng/mL. The electrocardiogram (ECG), magnetic resonance imaging (MRI), and superior vena cave (SVC) provide more information about cardiac responses in a mouse model of acute myocardial infarction (AMI). Further, magnetic resonance imaging helps to evaluate the cardiac output of an obesity induced myocardial injury mouse model. These methods play an essential role in monitoring the obesity based cardiac injury and hence, these studies were carried out. This is the first report to use the ECG, MRI, and SVC sampling methods to study the obesity based cardiac injury involving Syrian hamsters as animal models. The proposed SiNW-FET in this study shows greater sensitivity than the previously developed devices and demonstrates great potential for future applications in point-of-care (POC) diagnosis.

Using breath analysis as a screening tool to detect gastric cancer: a systematic review

Breath analysis has emerged as an experimental method of non-invasive screening of gastric cancer and identification of individuals suitable for confirmatory, diagnostic upper gastrointestinal endoscopy. We aimed to evaluate the accuracy and applicability of breath analysis for gastric cancer detection in adults.We searched MEDLINE, EMBASE, BIOSIS, CENTRAL, and Compendex up to 27 September 2020 for original studies analysing exhaled breath to detect gastric cancer in patients. Summary sensitivity and specificity analyses were obtained using a hierarchical bivariate method. Non-quantitative results were descriptively summarized. Risk of bias was assessed using the QUADAS-2 tool. This study protocol was pre-registered in PROSPERO (CRD42020139422).Twenty-four studies were included. Within these, breath analysis technologies most commonly used were mass spectrometry (MS)-based methods; other methods included volatile organic compound sensors and silicon nanowire field effect transistors. Fourteen studies (total n = 3028) involving all technologies reported quantitative results, with sensitivities ranging from 67%–100% and specificities from 71%–98%. The summary sensitivity across six studies utilizing MS-based breath analysis methods was 82.4% (95% CI: 78%–86%); summary specificity was 91.3% (95% CI: 83%–96%). Based on these values, we estimated that screening with MS-based breath tests could lower the number needed to screen (NNS) by more than eight-fold in the 15 countries with the highest prevalence of gastric cancer.Breath analysis is a promising method for gastric cancer detection with good diagnostic performance and potential to decrease the NNS for endoscopy-based gastric cancer detection. However, due to the heterogeneity of breath analysis technologies, rigorous studies with standardized, reproducible methods are needed to evaluate the clinical applicability of these technologies.