About

Zuofu Cheng is a Teaching Associate Professor at the University of Illinois, Urbana-Champaign, within The Grainger College of Engineering. He holds a B.S., M.S., and Ph.D. in Electrical Engineering from the University of Illinois at Urbana-Champaign, completed in 2006, 2010, and 2014 respectively. His doctoral dissertation focused on the design of a real-time GPU-accelerated acoustic simulation engine for interactive applications. Cheng's professional experience includes serving as the Director of Hardware Engineering at Inspirit-IoT in Urbana, Illinois, from 2017 to 2021. His research areas encompass acoustics and computer architecture. He has taught various courses related to electrical and electronic circuits, digital systems, electronic music synthesis, and semiconductors. Cheng's work contributes to advancing knowledge in acoustics and computer architecture, with a focus on real-time simulation and interactive applications.

Research topics

• Optoelectronics
• Nanotechnology
• Materials science
• Composite material
• Condensed matter physics
• Engineering physics
• Electrical engineering
• Optics
• Thermodynamics
• Engineering

Selected publications

• Ion Implantation Enhanced Nucleation Facilitates Heat Transport across Atomically-Sharp Semiconductor Interfaces

  arXiv (Cornell University) · 2026-02-14

  articleOpen accessSenior author

  Overheating is a critical bottleneck limiting the performance and reliability of next-generation high-power and high-frequency electronics. Interfacial thermal resistance constitutes a significant portion of the total thermal resistance. In this study, we report an ultrahigh thermal boundary conductance (TBC) of approximately 800 MW/m2-K at the atomically-sharp AlN-SiC interface, achieved through an ion implantation-enhanced nucleation epitaxy technique. This value is among the highest TBC values reported for semiconductor interfaces, confirmed by structural characterizations which show an ultrahigh-quality interface. Atomistic Green Function calculations reveal that elastic phonon transmission dominates the interface, with nearly half of the acoustic modes (0-15 THz) exhibiting near-unity transmission due to the atomically sharp structure. Furthermore, using high-energy-resolution electron energy loss spectroscopy, we probe vibrational properties with nanometer spatial resolution and identify unique interfacial phonon modes connecting the mismatched phonon spectra, confirmed by molecular dynamics simulations. The ultrahigh TBC is attributed to both the high elastic phonon transmission due to the high quality interfaces and the inelastic phonon scattering channel due to interfacial phonon modes. These findings not only advance the fundamental understanding of interfacial thermal transport but also provide a pathway for effective thermal management in emerging electronic devices.

  PublisherOA PDF

• Thermal conductance across bonded SiOx-SiOx interfaces in hybrid bonding process

  arXiv (Cornell University) · 2026-01-06

  preprintOpen accessSenior author

  Hybrid bonding is a pivotal technology for enabling three dimensional integrated circuits. Among the foremost challenges facing 3D IC implementation is thermal management, where a deep understanding of heat conduction across bonded interfaces is essential for addressing heat dissipation and reliability issues. Nevertheless, the thermal conductance of bonded dielectric-dielectric interfaces remains poorly understood. In this study, we employ the low-temperature bonding technique integral to hybrid bonding to fabricate SiO-SiO interfaces and investigate their thermal boundary conductance using time domain thermoreflectance. Structural characterizations show high quality bonded interfaces. By fitting the data with an equivalent multilayer thermal model, we establish a lower limit TBC of 150 MW/m2-K for the SiO-SiO interfaces, which corresponds to a thermal resistance lower than that of a 9.2-nm-thick dielectric layer. These findings offer valuable insights into thermal transport in hybrid-bonded structures and provide critical guidance for the thermal design of advanced packaging solutions.

  PublisherDOI

• Thermal conductance across bonded SiOx-SiOx interfaces in hybrid bonding process

  ArXiv.org · 2026-01-06

  articleOpen accessSenior author

  Hybrid bonding is a pivotal technology for enabling three dimensional integrated circuits. Among the foremost challenges facing 3D IC implementation is thermal management, where a deep understanding of heat conduction across bonded interfaces is essential for addressing heat dissipation and reliability issues. Nevertheless, the thermal conductance of bonded dielectric-dielectric interfaces remains poorly understood. In this study, we employ the low-temperature bonding technique integral to hybrid bonding to fabricate SiO-SiO interfaces and investigate their thermal boundary conductance using time domain thermoreflectance. Structural characterizations show high quality bonded interfaces. By fitting the data with an equivalent multilayer thermal model, we establish a lower limit TBC of 150 MW/m2-K for the SiO-SiO interfaces, which corresponds to a thermal resistance lower than that of a 9.2-nm-thick dielectric layer. These findings offer valuable insights into thermal transport in hybrid-bonded structures and provide critical guidance for the thermal design of advanced packaging solutions.

  PublisherOA PDF

• Ion Implantation Enhanced Nucleation Facilitates Heat Transport across Atomically-Sharp Semiconductor Interfaces

  Open MIND · 2026-02-14

  preprintSenior author

  Overheating is a critical bottleneck limiting the performance and reliability of next-generation high-power and high-frequency electronics. Interfacial thermal resistance constitutes a significant portion of the total thermal resistance. In this study, we report an ultrahigh thermal boundary conductance (TBC) of approximately 800 MW/m2-K at the atomically-sharp AlN-SiC interface, achieved through an ion implantation-enhanced nucleation epitaxy technique. This value is among the highest TBC values reported for semiconductor interfaces, confirmed by structural characterizations which show an ultrahigh-quality interface. Atomistic Green Function calculations reveal that elastic phonon transmission dominates the interface, with nearly half of the acoustic modes (0-15 THz) exhibiting near-unity transmission due to the atomically sharp structure. Furthermore, using high-energy-resolution electron energy loss spectroscopy, we probe vibrational properties with nanometer spatial resolution and identify unique interfacial phonon modes connecting the mismatched phonon spectra, confirmed by molecular dynamics simulations. The ultrahigh TBC is attributed to both the high elastic phonon transmission due to the high quality interfaces and the inelastic phonon scattering channel due to interfacial phonon modes. These findings not only advance the fundamental understanding of interfacial thermal transport but also provide a pathway for effective thermal management in emerging electronic devices.

  DOI

• Direct Integration of Polycrystalline Diamond With 3C‐SiC for Enhanced Thermal Management in GaN HEMTs: Impact of Grain Structure and Interface Engineering

  Advanced Materials Technologies · 2025-07-10 · 6 citations

  articleOpen access

  Abstract The direct integration of polycrystalline diamond (PCD) with semiconductors is crucial for enhancing heat dissipation in high‐power electronics. However, achieving low surface roughness (<1 nm) remains challenging. In this study, the direct bonding of PCD to 3C‐SiC for GaN high‐electron‐mobility transistors (HEMTs) on a 2‐inch PCD wafer is demonstrated using an advanced bonding technique. The PCD wafer (surface roughness: 2.48 nm) is bonded at room temperature, forming a 7 nm‐thick amorphous layer, which transformed into a 13 nm‐thick polycrystalline SiC layer after annealing at 1100 °C without cracks or separations. Thermal analysis revealed higher thermal conductivity of PCD's growth surface than single‐crystal diamond (SCD). However, the thermal resistance ( R TH ) of GaN HEMTs on PCD is 27% higher than on SCD, attributed to phonon scattering from smaller grain sizes on the nucleation surface. Removing the fine‐grained nucleation layer can enhance heat dissipation. This successful direct bonding of PCD with 3C‐SiC overcomes key integration challenges, enabling improved thermal transport and high‐power device reliability. To fully utilize PCD's thermal advantages, grain size optimization and interface engineering are essential to reduce phonon scattering, improve thermal transport efficiency, and maximize device performance for next‐generation high‐power electronics.

  PublisherOA PDFDOI

• Explainable AI for forensic speech authentication within cognitive and computational neuroscience

  Frontiers in Neuroscience · 2025-11-05

  articleOpen access1st author

  The proliferation of deepfake technologies presents serious challenges for forensic speech authentication. We propose a deep learning framework combining Convolutional Neural Networks (CNNs) and Long Short-Term Memory (LSTM) networks to improve detection of manipulated audio. Leveraging the spectral feature extraction of CNNs and the temporal modeling of LSTMs, the model demonstrates superior accuracy and generalization across the ASVspoof2019 LA and WaveFake datasets. Linear Frequency Cepstral Coefficients (LFCCs) were employed as acoustic features and outperformed MFCC and GFCC representations. To enhance transparency and trustworthiness, explainable artificial intelligence (XAI) techniques, including Grad-CAM and SHAP, were applied, revealing that the model focuses on high-frequency artifacts and temporal inconsistencies. These interpretable analyses validate both the models design and the forensic relevance of LFCC features. The proposed approach thus provides a robust, interpretable, and XAI-driven solution for forensic authentic detection.

  PublisherOA PDFDOI

• Thermal conductivity of cubic silicon carbide single crystals heavily doped by nitrogen

  Journal of Applied Physics · 2025-12-02 · 1 citations

  articleSenior author

  High-purity single-crystal wide-bandgap semiconductor cubic silicon carbide (3C–SiC) has the second-highest thermal conductivity among wafer-scale crystals (after diamond), making it ideal for thermal management in electronic devices. However, doping—essential for electrical property tuning—may significantly affect its thermal conductivity. While numerous theoretical studies exist, experimental data remain limited. In this work, the thermal conductivity of heavily nitrogen-doped 3C–SiC single crystals grown via the top-seeded solution growth method is measured by time-domain thermoreflectance. The results show a significant reduction (up to 30%) in thermal conductivity at nitrogen doping concentrations around 2 × 1020 cm−3. The doping concentration and distribution are investigated using secondary ion mass spectroscopy and atom probe tomography, revealing an atomic-scale uniform nitrogen distribution. Experimental results show a lower thermal conductivity reduction than previous density functional theory predictions, indicating weaker phonon–electron scattering than expected. Large-area thermal conductivity measurement and mapping reveal spatially uniform thermal conductivity in 3C–SiC at the micro-to-macroscale, emphasizing its practical utility and general high quality. These findings shed light on understanding the doping effects on thermal transport in semiconductors and support further exploration of 3C–SiC for electronics thermal management.

  PublisherDOI

• Experimental Observation of Extremely Strong Defect-Phonon Scatterings in Semiconductor Single Crystals

  ArXiv.org · 2025-04-29

  preprintOpen accessSenior author

  The role of doping in tailoring thermal transport in semiconductors is critical for efficient thermal management in electronic devices. While the effects of doping have been extensively studied to tune electrical properties, its impact on thermal transport has not yet been thoroughly explored, particularly with respect to experimental investigations into exceptionally strong non-Rayleigh defect-phonon scattering phenomena. Herein, by combining the high-quality growth and advanced characterizations of cubic silicon carbide single crystals with well controlled boron doping, we experimentally observe anomalous strong defect-phonon scatterings, among the strongest reported in common semiconductors, that exceeds the predictions of the classic mass difference model by tens of times in magnitude. The measured thermal conductivity of doped 3C SiC match excellently with those predicted by first principle calculations in which resonant scattering of low frequency phonon is considered. Our findings not only shed light on the fundamental understanding of defect-phonon interactions and will also impact applications such as thermal management of electronics.

  PublisherOA PDFDOI

• Nonmonotonic phonon thermal conductivity modulated by electron–phonon interaction in graphene/h-BN heterostructures

  Applied Physics Letters · 2025-09-30

  article

  Graphene van der Waals (vdW) heterostructures, particularly those combined with hexagonal boron nitride (h-BN), exhibit unique electron–phonon interaction (EPI), enabling remarkable electron transport phenomena such as ultrahigh mobility, electron hydrodynamic flow, and superconductivity. Despite extensive studies on electron transport, the effect of EPI on phonon thermal transport in such heterostructures remains underexplored. In this Letter, we study the EPI-driven modulation of phonon thermal conductivity (kph) in the bilayer graphene/h-BN heterostructure via first-principles calculations. We find that kph varies nonmonotonically with carrier concentration due to the evolution of the Fermi surface near the Dirac point. The maximum reduction in kph compared to its intrinsic value reaches 41% at 300 K and 51% at 200 K, significantly exceeding the reduction reported for pristine graphene at a comparable carrier concentration. This significant reduction originates from the broken out-of-plane symmetry in the graphene/h-BN heterostructure, which enables direct flexural (ZA) phonon–electron coupling, and the strong EPI of in-plane shear (TA′) mode induced by the interlayer vdW interaction. A phonon branch-resolved analysis further shows that the relative contribution of ZA phonon–electrons scattering to the reduction in kph decreases from 68% to 25% with increasing carrier concentration, while the contributions from TA and TA′ phonon–electron scattering initially rise and eventually stabilize at around 30%. Our results provide insight into how EPI affects the thermal transport of graphene vdW heterostructures and offer guidance for thermal management in graphene-based nanodevices.

  PublisherDOI

• ATSim: A Fast and Accurate Simulation Framework for 2.5D/3D Chiplet Thermal Design Optimization

  2025-10-21

  article

  This paper reviews the thermal challenges in 2.5D/3D chiplet integration systems and introduces ATSim, a simulation framework with applications to chiplet thermal optimization. ATSim enables fast and accurate thermal simulation for both steady-state and transient conditions. It supports nonlinear, heterogeneous, and anisotropic materials. The framework features a multilevel grid generation scheme based on a novel hybrid tree structure. Compared to mainstream academic and commercial tools, ATSim achieves high accuracy and efficiency, making it a powerful tool for evaluating and improving thermal designs, including applications like thermal-aware placement.

  PublisherDOI

Frequent coauthors

• Samuel Graham

  University of Maryland, College Park

  69 shared

• Mark S. Goorsky

  40 shared

• Jingjing Shi

  Georgia Institute of Technology

  32 shared

• Luke Yates

  Sandia National Laboratories

  26 shared

• Karl D. Hobart

  25 shared

• Tingyu Bai

  25 shared

• Marko J. Tadjer

  United States Naval Research Laboratory

  22 shared

• Tatyana I. Feygelson

  United States Naval Research Laboratory

  18 shared

Education

• PhD, Mechanical Engineering

  Georgia Institute of Technology

  2019

• MS, Mechanical Engineering

  Iowa State University

  2015