The Zeta™-388 non-contact profiler delivers 3D metrology and imaging capabilities and is equipped with an integrated isolation table and a cassette-to-cassette wafer handling system for fully automated operations.
Powered by ZDot™ technology, the system simultaneously captures high-resolution 3D data along with a True Color infinite focus image. Designed to support both research and development (R&D) and production settings, the Zeta-388 features Multi-Mode optics, user-friendly software, low ownership costs, and SECS/GEM communications compatibility
Product Details
Product Description
Image Credit: KLA Instruments™
The Zeta-388 optical profiler is an advanced, non-contact, 3D surface topography measurement system. Improving on the features of the Zeta-300, it includes a cassette-to-cassette handler to facilitate fully automated measurements.
The system utilizes the patented ZDot technology and Multi-Mode optics, which enable it to handle a diverse range of sample types, from transparent to opaque and smooth to rough textures, measuring step heights from nanometers to millimeters.
The Zeta-388 combines six different optical metrology technologies into one configurable and user-friendly system. Its ZDot measurement mode simultaneously captures high-resolution 3D scans and True Color infinite focus images.
Additional measurement techniques integrated into the system include white light interferometry, Nomarski interference contrast microscopy, and shearing interferometry.
Film thickness measurements are possible with either ZDot or an integrated broadband reflectometer. Beyond metrology, the Zeta-388 functions as a high-end microscope for sample review or automated defect inspection, making it suitable for both R&D and production environments. It offers detailed assessments of step height, roughness, and film thickness alongside its defect inspection capabilities and automated wafer handling.
Moreover, the Zeta-388 is tailored for automated metrology solutions in the manufacturing of wireless devices such as Surface Acoustic Wave (SAW), Bulk Acoustic Wave (BAW), and Thin Film Bulk Acoustic Resonator (FBAR) devices.
Features
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- Easy-to-use non-contact optical profiler with ZDot and Multi-Mode optics for a variety of applications
- High-quality microscope sample evaluation or defect inspection
- ZDot: Simultaneously gathers a high-resolution 3D scan and a True Color infinite focus image
- ZI: Zeta phase and vertical scanning interferometry (PSI and VSI) allow for wide-area observations with a high z-resolution
- ZIC: Interference contrast for quantitative 3D data from surfaces with sub-nanometer roughness
- ZFT: An integrated broadband reflectometer measures the film thickness and reflectance
- AOI: Automatic optical inspection to quantify flaws in the sample
- Production capability: Fully automated measurements with sequencing and pattern recognition
- Wafer handler: Automatically load samples with diameters of 100 to 200 mm that are opaque (like silicon) and transparent (like sapphire)
Applications
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- Film thickness: Transparent film thickness from 30 nm to 100 µm
- Defect inspection: Capture defects greater than 1 µm
- Defect review: KLARF files are used to navigate to faults, assess 3D surface topography, and scribe defect locations
- Step height: 3D step height from nanometers to millimeters
- Texture: 3D roughness and waviness on smooth to extremely rough surfaces
- Form: 3D bow and shape
- Stress: 2D thin film stress
Industries
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- PCB (printed circuit board) and flexible PCB
- MEMS: Micro-electro-mechanical systems
- Medical devices and microfluidic devices
- Wireless Device Manufacturing for SAW, BAW, and FBAR devices
- LED: Light-emitting diodes and PSS (patterned sapphire substrates)
- Semiconductor and compound semiconductor
- Semiconductor WLCSP (wafer-level chip scale packaging)
- Semiconductor FOWLP (fan-out wafer-level packaging)
Applications
Step Height
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The Zeta-388 excels in measuring 3D, non-contact step heights, ranging from nanometers to millimeters. It utilizes ZDot and Multi-Mode optics, offering diverse methods for precise step height measurement. ZDot serves as the primary technique, efficiently capturing step heights from tens of nanometers up to millimeters. Additionally, ZI interferometry is available for measuring extensive step heights across large areas.
Film Thickness
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The Zeta-388 effectively measures the thickness of transparent films using either ZDot or ZFT measurement techniques. ZDot is particularly adept at measuring thicker transparent films over 10 µm, such as photoresist layers or microfluidic device coatings on substrates with higher refractive indices.
The ZFT technique, incorporating an integrated broadband reflectometer, measures film thickness ranging from 30 nm to 100 µm for single or multi-layer stacks, with user input or model-based spectrum fitting.
Texture: Roughness and Waviness
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The device quantifies 3D texture by measuring the roughness and waviness of surfaces. ZDot is used to measure roughness from tens of nanometers to extremely rough surfaces, while Zeta interferometry tackles smooth surface measurements from angstroms to microns.
The software employs filters to separate roughness and waviness, calculating parameters like root mean square (RMS) roughness. Nomarski interference contrast microscopy provides detailed visualizations of fine surface details by highlighting slight changes in slope.
Form: Bow and Shape
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The Zeta-388 can assess both 2D and 3D forms, including the shape or bow of a surface. It is particularly useful in measuring wafer bow, which may arise from layer mismatches in the production of semiconductor or compound semiconductor devices. It can also determine the 3D height and radius of curvature for various structures, such as lenses.
Stress: Thin Film Stress
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The Zeta-388 is adept at measuring stress induced during the fabrication of multi-layer devices like semiconductors. It accurately gauges the surface bow using a stress chuck that maintains the sample in a neutral position. Changes in shape from processes like film deposition are analyzed to calculate stress, utilizing Stoney’s equation.
The system measures 2D stress by recording the height of the sample surface at predefined intervals across its entire diameter, synthesizing this data into a comprehensive sample shape profile.
Automated Defect Inspection
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The Zeta-388 excels in Automated Optical Inspection (AOI), swiftly inspecting samples, distinguishing various defect types, and mapping defect densities across the sample. Coupled with its 3D metrology capabilities, the Zeta-388 offers detailed insights into defects that are unattainable with traditional 2D inspection systems, thus accelerating the identification of defect sources.
Defect Review
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The Zeta-388 uses an inspection tool KLARF file to navigate to defect locations. Users can examine defects using a high-quality microscope or assess the defect’s topography, including height, thickness, or texture, providing deeper insights than 2D defect inspection systems.
Additionally, the Zeta-388 can mark defects with a scribe, simplifying their detection on tools like SEM review tools that have limited viewing scopes.
LED Pattern Sapphire Substrates (PSS)
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The Zeta-388 optical profiler is adept at the metrology and inspection of patterned sapphire substrates. Utilizing ZDot technology, through-sample lighting, and custom algorithms, it efficiently measures the height, width, and pitch of PSS bumps. It also measures the photoresist before and after patterning to enable sample rework before the sapphire etching process.
Its automated defect inspection capabilities facilitate the quick identification of critical defects in PSS substrates, such as missing bumps, bump bridging, tear-outs, and contamination. An automated wafer handling system minimizes the need for operator handling, reducing sample contamination.
Semiconductor and Compound Semiconductor Packaging
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The Zeta-388 meets the metrology needs of Wafer-Level Chip Scale Packaging (WLCSP) and Fan-Out Wafer Level Packaging (FOWLP). Its key technology allows for the measurement of plated copper height through a dry photoresist film, measuring down to the seed layer to assess copper pillar height, photoresist thickness, and the height difference between copper and photoresist.
It also measures redistribution lines (RDL), under bump metallization (UBM) height and texture, critical dimensions of photoresist openings, and the thickness of both photoresist and polyimide. It ensures the coplanarity of metal contacts to verify that bump heights meet the connectivity requirements of final device packaging.
Laser Ablation
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The Zeta-388 can assess topographical changes caused by laser surface processing in various industries, including semiconductors, LEDs, microfluidics, PCBs, and more. This precision is critical for applications such as measuring the height and width of wafer ID marks in the semiconductor industry to ensure they remain legible through multiple processing steps.
Microfluidics
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The Zeta-388 is capable of measuring microfluidic devices made from materials like silicon, glass, and polymers. It quantifies dimensions such as the height, width, edge profile, and texture of channels, wells, and control structures. It can also measure the final device once sealed with a transparent top cover, adjusting for refractive index changes and quantifying stress changes caused by the cover's application.
Biotechnology
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The Zeta-388 is ideal for biotechnology applications, performing non-contact measurements of a wide range of sample surfaces and features, from nanometers to millimeters.
It is particularly useful for measuring high aspect ratio features like the depth of deep wells in biotech devices or micro-needle array structures used in drug delivery, leveraging its high numerical aperture lenses and capability to resolve very low reflectance samples.
Options
The options for the Zeta™-388 Optical Profiler can be added either when purchasing the new product or at a later date.
ZFT: Zeta Film Thickness
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The Zeta-388 is equipped with an integrated broadband spectrometer designed for measuring the thickness of transparent thin films ranging from 30nm to 100µm. It supports measurements of both single-layer and multi-layer film stacks, allowing users to select the appropriate refractive index values from a comprehensive materials library. This capability enables the mapping of film thickness across a sample to assess uniformity.
ZFT technology is particularly effective on surfaces with very low reflectance, below 0.1 %. Traditional film thickness tools often struggle to detect signals from such surfaces, which rely on specular reflection to analyze phase changes and other properties. However, the Zeta-388 utilizes broadband white light and normal incidence illumination, making it versatile for measuring a wide range of optically transparent films, even those with minimal reflectance.
ZI: Zeta Interferometry
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The Zeta-388 is equipped to support both Phase Scanning Interferometry (PSI) and Vertical Scanning Interferometry (VSI) when used in conjunction with a piezo stage and an interferometric objective lens. PSI is adept at quickly measuring step heights ranging from angstroms to hundreds of nanometers.
On the other hand, VS, also recognized as White Light Interferometry (WLI), is capable of measuring step heights from hundreds of nanometers up to hundreds of microns. Both methods achieve resolutions better than a nanometer and their performance is not dependent on the numerical aperture of the objective lens.
ZIC: Zeta Interference Contrast
Image Credit: KLA Instruments™
The Zeta-388 uses Nomarski differential interference contrast microscopy to improve fine surface detail imaging. Nomarski microscopy highlights variations in slope on the sample surface by using polarization and a prism to alter the phase.
This makes it possible to see defects in extremely smooth surfaces, like a contamination monolayer. By comparing the change in slope with roughness recorded using an alternative method, the ZIC scanning mode can turn these images into quantitative measures of sub-nanometer level roughness.
ProfilmOnline Web Application
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The Filmetrics ProfilmOnline is a cloud-based platform for 3D data visualization and analysis. It was created as a component of the Profilm software package. Users can exchange, save, examine, and analyze 3D data on ProfilmOnline from a computer or a mobile device. Apps are available for iOS and Android, and a wide range of file types are supported. Encrypting data can improve security.
Objective Lenses
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There are a wide range of objective lenses available, including normal objectives ranging from 2.5× to 150×, long working distance objectives, ultra-long working distance objectives, refractive index corrected objectives, through transmissive objectives, liquid immersion objectives, and vertical scanning interferometry objectives.
Couplers
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The Zeta-388 can be outfitted with four different optical couplers to adjust the optics magnification. The system can be set with a 1× coupler to maintain the native magnification or with 0.35×, 0.5×, or 0.63× couplers to increase magnification.
Objective Lens Turret
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The Zeta-388 can be equipped with a manual turret with five or six positions and an objective lens sensor for automatic objective identification. The device can also be equipped with a 6-position motorized turret for completely automated operation.
Sample Lighting
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The Zeta-388 employs dual high-brightness white LEDs for standard lighting. Additionally, it offers backlighting through the sample chuck, enhancing visibility for challenging transparent samples like patterned sapphire substrates (PSS). The Zeta-388 is also equipped to support side darkfield lighting, further improving its versatility in handling a variety of lighting conditions for different sample types.
Stages
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The Zeta-388 can be customized with several stages to improve system performance. To detect nanometer-level step heights using the ZDot™ or ZI measurement modes, consider adding a piezo Z-axis stage to boost z resolution. The XY stage is motorized and can be set up with a standard chuck, a bowed wafer chuck, or a backside illumination chuck.
Sample Chucks
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The Zeta-388 includes a variety of chucks to meet application needs for samples ranging from 100 to 200 mm, including chucks for bowed wafers. Backlight chucks are available for transparent substrates to offer transmitted illumination, which is essential for patterned sapphire substrates.
Isolation Tables
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The Zeta-388 system has passive isolation at the base. An active isolation table is offered for applications that require further isolation. The Zeta-388 includes a basic acoustic enclosure that protects the user from sample handler movements and isolates the system from environmental noise.
Step Height and Film Thickness Standards
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VLSI standards provide NIST traceable thin and thick film step height specifications that are used by the Zeta-388. The standards feature an etched quartz step with a chrome coating. There is an 8 nm to 250 µm step height range available.
A certified multi-step standard has nominal step heights of 8, 25, 50, and 100 µm. The standard includes different pitch patterns for XY calibration. For ZFT, a certified film thickness standard with a nominal silicon dioxide film thickness of 270 nm and a reference silicon surface is provided. More mirror samples and reference roughness are available.
Automated Sequencing Software
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The automated sequencing software of the Zeta-388 leverages the motorized XY stage, enabling users to pre-program specific measurement locations on the sample. The system then automatically conducts measurements at each designated site and saves the results in folders defined by the user. It generates an output report containing sample statistics to summarize the findings.
Additionally, the advanced sequencing software incorporates pattern recognition technology to automatically align the sample, facilitating fully automated measurements and minimizing the potential for operator error. Auto calibration is also available and can be activated when using embedded standards on the stage.
Stitching Software
Image Credit: KLA Instruments™
The automated image stitching software of the Zeta-388 takes advantage of the motorized XY stage to merge adjacent scans, creating a comprehensive stitched data set that extends beyond a single field of view. This system methodically measures each site, aligns the images seamlessly, and consolidates them into a unified data set. These results are then structured to be analyzed just like any standard results file.
Apex Analysis Software
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The Apex analysis software significantly enhances the Zeta-388's standard data analysis capabilities. It includes a comprehensive suite of analysis tools for leveling, filtering, measuring step height, and assessing surface roughness and topography.
Apex is compliant with ISO roughness calculation methods and local standards such as ASME. Additionally, it functions as a robust report-writing platform, allowing users to add text and annotations and establish pass/fail criteria. Apex is available in eleven languages.
Offline Analysis Software
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The Zeta-388's offline analysis software mirrors the data analysis and recipe creation capabilities available on the tool itself. This feature enables users to create recipes and perform data analysis without occupying the instrument during valuable operational hours.