If you’ve been following the evolution of advanced packaging, you know that the industry is pushing boundaries like never before. From high-performance computing to industry-upending AI devices, the demand for smaller, faster, and more powerful chips is driving innovation at every level.
If you’ve been following the evolution of advanced packaging, you know that the industry is pushing boundaries like never before. From high-performance computing to industry-upending AI devices, the demand for smaller, faster, and more powerful chips is driving innovation at every level. One of the unsung heroes in this transformation: Glass carriers.
These carriers are becoming essential for applications involving high-bandwidth memory (HBM), 2.5D/3D integration, and chiplet architectures. During the manufacturing process, glass carriers serve as mechanical support for thin wafers and panel-level packages. Why? Glass carriers are noted for their warpage resistance, superior rigidity, and thermal stability. This combination of glass’ exceptional flatness and rigidity enables the precise placement of dies and interposers. Additionally, glass is optically transparent, which allows through-glass alignment during bonding and stacking, a critical capability for 3D integration where multiple layers must be accurately registered.
The benefits of glass carriers, however, come with several challenges, none of which should come as a surprise to anyone who has ever handled glass, whether in the fab or at home. Glass is fragile and, as such, is prone to surface defects, subsurface inclusions, and residual stress. Each of these can negatively impact die attachment quality, interconnect reliability, and die yield.
Let’s take a look at three major yield-killing culprits.
Surface defects such as particles, pits, and scratches are among the most common issues and may occur during glass carrier handling and processing, compromising the structural integrity and performance of advanced packaging assemblies (Figure 1). Particles can interfere with the bonding process, leading to poor adhesion or electrical discontinuities, while pits and scratches can propagate stress points that weaken the carrier during thermal cycling or molding.
However, subsurface inclusions and organic contamination, which are often introduced during reclaim or cleaning, pose more critical challenges. Inclusions within the glass can create localized stress concentrations, while organic residues can reduce UV transmission and cause bonding failures. These contaminants are particularly problematic in high-density interconnect environments where optical clarity and surface purity are critical.
Figure 1: Common glass carrier defects
In addition to surface and subsurface defects, residual stress represents a concern. Over time, these stress points, manifesting during thermal processing or mechanical handling, can lead to cracks or delamination, undermining the thermo-mechanical integrity of the entire package.
These potential challenges are compounded each time a glass carrier is reused in an effort to reduce overall packaging costs. Fortunately, technologies have been developed to address this obstacle. These technologies integrate AI-driven defect classification, real-time analytics, and adaptive scanning modes to maintain throughput without sacrificing accuracy, enabling manufacturers to detect surface anomalies, subsurface inclusions, and stress-induced defects with unprecedented precision.
Today’s wafer-based inspection platforms utilize laser scatterometry and imaging techniques to inspect for nanometer sized defects on a variety of opaque and transparent/semi-transparent substrates. These substrates may be suitable for either R&D or high-volume advanced IC substrate (AICS) and fan-out panel level processing (FOPLP) environments. Proprietary inspection technology with multiple detection channels and advanced signal processing algorithms is applied to achieve accuracy and reliability in glass carrier inspection.
Figure 2: Results of top (blue) and bottom (red) defect mapping.
With each channel optimized to capture unique scattering and reflection signatures, the technology differentiates between surface and subsurface defects, as well as stress-related anomalies, with remarkable accuracy. Surface particles, scratches, pits, bumps, surface contamination, film or bulk wafer stress, voids/inclusions can be detected, measured, characterized, and imaged. One of the most significant capabilities of this technology is the ability to conduct simultaneous top, bottom, and internal defect mapping, a critical need for transparent and semi-transparent substrates where defects can occur across multiple planes (Figure 2).
Beyond defect detection, Angstrom-level film thickness measurement provides precise control over surface coatings and residual layers. This capability is particularly valuable in the glass reclaim process where even minor variations in film thickness can impact UV transmission and bonding performance. By enabling accurate defect detection and grading, only glass carriers meeting stringent quality standards are returned to production.
By introducing technologies that mitigate risks by providing comprehensive defect mapping and stress analysis, manufacturers are able to maintain the mechanical and thermal integrity required for next-generation devices. This capability is especially valuable in markets such as AI devices, high-performance computing, and automotive electronics where reliability is non-negotiable. With this combination of advanced optical technology and robust algorithmic analysis, manufacturers can successfully achieve higher yields, lower costs, and greater confidence in their packaging processes.
As packaging complexity grows and the use of glass carriers increases, inspection systems that combine multi-depth defect mapping and stress analysis will become indispensable for ensuring yield and reliability in AI and HPC devices. With the explosive growth in AI-driven data centers and advanced packaging architectures, manufacturers need solutions that combine accuracy, speed, and cost efficiency. The laser-based wafer inspection technology discussed in this blog meets several glass carrier challenges head-on while enabling advanced packaging houses to maintain defect-free glass carriers in support of next-generation advanced packaging.
The future of glass carriers is clear: with the right technologies at the ready, manufacturers have the tools and the means to meet the growing needs of the AI and HPC markets.
Jason Lin is Director of Product Marketing at Onto Innovation.
We’d love to connect with you.
Looking to learn more about our innovative solutions and capabilities? Our team of experts is ready to assist you. Reach out today and let’s starts a conversation about how we can help you achieve your goals.
"*" indicates required fields
The FAaST system is a versatile, non-contact electrical metrology platform, with an option to combine micro and macro corona-Kelvin technologies together with digital surface photovoltage (SPV). It enables high-resolution dielectric and interface measurements across a wide range of dielectric materials, supporting both R&D and high volume manufacturing.
The primary application of non-contact CV metrology is monitoring dielectric properties during IC manufacturing. Unlike conventional electrical measurements, it requires no sample preparation, eliminating the need for MOS capacitor structures. This reduces metrology cost and enables fast data feedback in both R&D and manufacturing environments.
The corona-Kelvin method uses a corona discharge in air to deposit an electric charge (DQC) on the wafer surface. A vibrating Kelvin-probe then measures the resulting surface voltage (V), enabling determination of the differential capacitance (C= DQC/DV). By monitoring surface voltage in both dark and illuminated conditions, the system separates two key components: dielectric voltage (VD) and semiconductor surface potential (VSB), enabling determination of flat band voltage (VFB).
Analysis of the resulting charge-voltage data yields electrical parameters, including trap density (Dit), flat band voltage (Vfb), dielectric charge (Qtot), dielectric capacitance (CD), Equivalent Oxide Thickness (EOT), leakage current, and tunneling characteristics.
As your partner for innovative solutions, we’re always here for you.
Discover how our cutting-edge semiconductor solutions are engineered to meet your most complex challenges: delivering performance, reliability and innovation where it matters most.
"*" indicates required fields
The MBIR system is a revolutionary in-line, non-destructive infrared reflectometry system that enables critical process control of high aspect ratio structures, films and epitaxial structures. It meets the needs of leading-edge customers with its high speed and process coverage.
As more high aspect ratio processes are used in multiple industry segments, there are metrology needs for monitoring of related processes, including dimensions and properties of carbon film hard masks and etched 3D structures.
The MBIR system delivers high-throughput, low COO, non-contact, non-destructive measurements of dimensions and uniformity of layers and etched structures used in integrated circuit manufacturing. The small spot size makes the tool suitable for measurements of scribe line test structures as in-line process control. The unique technology and analysis capability simplifies system calibration requirements and removes the effect of substrate variations for key layer measurements.
While the software contains advanced features for measurement recipe and analysis model creation, it has a user-friendly interface and implementation that allows the fab customers to create and manage the recipe system for MBIR tool fleets.
Thickness map from amorphous carbon film
As your partner for innovative solutions, we’re always here for you.
Discover how our cutting-edge semiconductor solutions are engineered to meet your most complex challenges: delivering performance, reliability and innovation where it matters most.
"*" indicates required fields
A suite of OCD modeling software and computing hardware that enables the full capability and connectivity across all Onto OCD and thin film metrology systems, including Atlas, Aspect, Iris and IMPULSE systems.
Onto Innovation’s OCD technology offers powerful modeling and computing packages to support various phases of film and OCD measurement setup, data management, and fleet management. These capabilities include model building, runtime data analysis, system calibration, data analytics, data connectivity and management, spectrum management and fleet matching.
Onto OCD solutions consist of several modeling and computing components, including Ai Diffract™ modeling software, runtime onboard computer, offline modeler, offline model building clusters, and recipe & data management server. Each component seamlessly extends OCD capabilities to Onto’s standalone and integrated metrology systems, providing end-to-end capabilities from offline recipe support and development to fab-wide networking and connectivity for easy fleet management.
Ai Diffract software is a powerful modeling, visualization and analysis software with an intuitive 3D modeling interface to simplify the building and visualization of today’s most complex semiconductor devices. It offers OCD modeling and advanced machine learning capabilities, next-generation real-time regression, offline sensitivity analysis tools and comprehensive GUI and structure input for true multi-variant modeling. Ai Diffract software’s proprietary fitting algorithms enable fast and accurate calculations for signal processing, helping ensure high fidelity model-based measurements. Automation features for spectral fitting, recipe optimization, and sensitivity analysis offer great user productivity. The first-in-market AI-guided engine synergizes physics-based modeling and machine learning to deliver the most robust solution with quick time to solution.
Ai Diffract Modeler is the offline analytical engine that allows users to create and edit recipes offline. It supports multiple users and can connect to Ai Diffract cluster for high intensity computing.
Ai Diffract Onboard is the on-tool runtime engine that maximizes tool throughput for complex use cases. It ensures rapid analysis without interfering with system operation or impacting throughput.
Ai Diffract Cluster is an enterprise scale computing server deployed for offline recipe development or in-line real-time regression. Optimized to support the workload of Ai Diffract software analysis, it scales based on fleet size, recipe numbers, and computing intensity.
Recipe Distribution Server (RDS) / Nexus Servers is a fab-wide networking and server system for fleet management and connectivity. RDS/Nexus servers provide connectivity and support to Ai Diffract recipe management and distribution, data/spectrum feed-forward and feedback, spectrum management, and fleet management.
As your partner for innovative solutions, we’re always here for you.
Discover how our cutting-edge semiconductor solutions are engineered to meet your most complex challenges: delivering performance, reliability and innovation where it matters most.
"*" indicates required fields
The PrimaScan wafer defect inspection system delivers a flexible, high sensitivity solution at the lowest cost of ownership per pass.
The PrimaScan system utilizes laser scatterometry and imaging techniques leveraging proprietary optics and sensing technologies for reliable inspection of nanometer sized defects on a variety of opaque and transparent/semi-transparent substrates suitable for either R&D or high-volume manufacturing environments. With multiple detection channels, the system can detect, measure, characterize and image surface particles, scratches, pits, bumps, surface contamination, film or bulk wafer stress, voids/inclusions, including chips and cracks at the wafer edge.
The PrimaScan system addresses challenges in both incoming wafer quality control and in inline process monitoring. Capable of handling multiple substrate materials, it uniquely addresses inline process defect and contamination monitoring in wafer-based production environments.
Designed with versatility in mind the PrimaScan system can handle a variety of wafer sizes and substrate types
As your partner for innovative solutions, we’re always here for you.
Discover how our cutting-edge semiconductor solutions are engineered to meet your most complex challenges: delivering performance, reliability and innovation where it matters most.
"*" indicates required fields
The IVS 380 System delivers overlay, CD and z-height metrology for advanced packaging, power, compound semi and MEMS, offering world class performance and flexibility to accommodate substrates of different sizes and thickness without hardware changes.
The IVS 380 is an optical overlay, CD & z-height metrology system designed for high volume manufacturing, with SMIF (200mm substrate) or FOUP (300mm substrate) load ports compatibility. It handles various substrates for advanced packaging, including Si, glass and CCL, and accommodates sizes of 200mm and 300mm.
Building on the IVS family’s 40 years of experience in CMOS, MEMS and compound semiconductor applications, the IVS 380 system possesses the versatility to tackle overlay, CD and z-height measurements for diverse substrates and layers. It measures critical dimensions in the xy plane and the vertical z-heights of features like RDL metal lines, posts and bumps. The optics enable focus on mostly transparent materials such as photoresists and rough surfaces such as electroplated copper.
Enter your information below and we’ll send you a unique passcode to view our IVS 3D Demo.
As your partner for innovative solutions, we’re always here for you.
Discover how our cutting-edge semiconductor solutions are engineered to meet your most complex challenges: delivering performance, reliability and innovation where it matters most.
"*" indicates required fields