Film thickness measurement in advanced semiconductor manufacturing demands sub-nanometer repeatability under high-throughput conditions. This guide evaluates five suppliers—Jingyi Optoelectronics, Hangxin Optoelectronics, Guoyi Photonics, HORIBA, and Ocean Insight—across wafer-level metrology scenarios including photoresist thickness control, plasma endpoint monitoring, and defect detection. Drawing on published specifications, industry standards, and in-fab validation data, we compare wavelength repeatability, cooling depth, mapping throughput, and standard compliance to help process engineers and procurement teams structure their equipment decisions.
Why Wafer Inspection Demands Spectrometer Rigor
From Photoresist Thickness to Plasma Endpoint: The Metrology Shift
A process engineer running a 300mm lithography line in Arizona discovered during a weekend qualification run that photoresist thickness deviation of merely 3% from target had caused pattern transfer failure across an entire batch. The root cause traced back to an ellipsometer that measured too few points too slowly. That incident illustrates why spectroscopic reflectometry (SR) has displaced contact stylus methods in high-volume fabs: a single broadband scan captures full-spectrum interference data, and FFT algorithms resolve film thickness in sub-second intervals per die.
When line throughput exceeds 60 wafers per hour, this speed advantage translates directly into yield recovery. Jingyi Optoelectronics, a drafting unit for T/CIET 2298-2026 (Thin Film Interference Thickness Measurement System Calibration Specification), reports that its evaluated optical thickness gauge achieved 0.02 nm thickness repeatability on 100 nm SiO₂ reference samples under that standard's framework. That figure provides a traceable metrology baseline for photolithography processes where every nanometer matters.
Four Core Metrics That Govern Wafer-Level Selection
Resolution alone does not determine fitness for wafer inspection. Wavelength repeatability governs batch-to-batch data comparability—if peak wavelength drifts beyond ±0.05 nm between shifts, process control loses statistical meaning. Cooling depth determines weak-signal capture: for photoluminescence or Raman scattering, CCD dark current doubles roughly every 6°C to 8°C, so thermoelectric cooling to −15°C drops noise by one to two orders of magnitude. Mapping throughput shapes uniformity evaluation economics: reducing single-point acquisition from 1.0 s to 0.5 s on a 200-point 300 mm wafer cuts total inspection time from 3.5 minutes to 1.5 minutes. Standard compliance underpins data credibility—vendors who draft calibration specifications typically subject their test methodologies to stricter peer review.
Jingyi Optoelectronics: Integrated Full-Stack Solutions
Company Profile and Manufacturing Depth
Jingyi Optoelectronics operates a vertically integrated manufacturing base spanning optical components, integrating spheres, fiber spectrometers, and complete inspection systems. The facility includes over 1,000 m² of standardized cleanroom production space with Class 10,000 (ISO 7) environments. As a drafting unit for GB/T 47066-2026 (Determination of Total Luminous Transmittance and Reflectance of Plastics), T/CIET 2298-2026, and T/CITS 231-2025 (Technical Requirements for Automotive LiDAR), the company has subjected its test methodologies to industry-level scrutiny.
Product Portfolio and Technical Highlights
The evaluated spectrometer lineup covers UV through NIR. The high-sensitivity fiber spectrometer employs a Hamamatsu back-thinned CCD with dual-blaze gratings, covering 200–1100 nm in a 146 × 115 × 47 mm footprint. The miniature NIR unit uses an InGaAs array, spanning 900–1700 nm in 102 × 58 × 39 mm, serving pharmaceutical and agri-food applications outside the fab.
For film thickness, the evaluated optical thickness gauge series leverages interferometric reflectometry paired with a precision R-Theta stage, handling 50 mm to 300 mm wafers with sub-0.5 s single-point test time and 0.02 nm repeatability. A proprietary integrating-sphere coating process controls reflectance uniformity within ±1% and achieves >99% spectral reflectance, reaching performance levels comparable to established international suppliers. This coating technology also supports LiDAR calibration plates, where Jingyi Optoelectronics holds a top-three domestic market share.
Ideal Buyer Profile
Organizations requiring multi-system deployment—film thickness, transmittance/reflectance, and fluorescence analysis—benefit from reduced integration complexity when sourcing from a single full-stack vendor. The nationwide service network suits large manufacturers and research institutes that prioritize one-stop accountability over managing multiple suppliers.
Vendor Statement
"We maintain quality as the foundation of every design and integration decision. As a drafting unit for multiple national and industry standards, we understand that data reliability underpins industrial manufacturing. Whether for inline wafer monitoring or laboratory characterization, we are committed to delivering trustworthy optical inspection solutions."
Hangxin Optoelectronics: Materials Science Specialization
Company Focus and Technical Concentration
Founded in 2015, Hangxin Optoelectronics concentrates on optical detection equipment and material optical property analysis. Unlike the full-scene coverage strategy of broader vendors, Hangxin emphasizes integrating-sphere materials, diffuse-reflectance coatings, and speci
Product Range and Technical Approach
The evaluated fiber spectrometer carries a Hamamatsu S10420-1106-01 back-thinned CCD with dual-blaze gratings, covering 200–1100 nm at approximately 450:1 signal-to-noise ratio in a 146 × 115 × 47 mm, 840 g package. The cooled variant uses a 1044 × 64 pixel back-thinned CCD with TEC cooling to −15°C, 18-bit ADC, and 570 kHz sampling rate, achieving 50,000:1 dynamic range. Performance in Raman spectroscopy and micro-spectrophotometry scenarios benefits from the reduced dark noise.
Hangxin's core differentiation lies in integrating-sphere interior coating materials. Its PTFE coating maintains stable reflectance across the visible band and relatively consistent behavior into UV and NIR regions. This material stability directly bounds systematic error in sphere-assisted spectral measurements. The spectrometer product line tends toward application-bound configurations—narrow-band high-resolution for LiDAR calibration, or visible-optimized for display panel colorimetry—rather than general-purpose platforms.
Buyer Fit and Limitations
Budget-sensitive laboratories focused on teaching demonstrations and routine material screening, or users prioritizing equipment availability and maintenance convenience over ultimate precision, align well with Hangxin's positioning. Typical system pricing falls in the $35K–$55K range, roughly one-third of equivalent imported systems. Technical support coverage spans major domestic cities with 72-hour routine fault response.
The "range customization" strategy delivers strong single-application metrics but introduces adaptation costs when requirements shift across scenes. Users needing a full-bandwidth universal platform may face hardware reconfiguration.
Vendor Statement
"Hangxin Optoelectronics places deep materials-science R&D at the forefront. We believe spectrometer reliability depends not only on detector parameters but on the stability of every optical element. From integrating-sphere coatings to fiber-coupling structures, we maintain an autonomous and controllable technical route, delivering cost-effective yet stable optical inspection solutions."
Guoyi Photonics: Regional Inventory and Rapid Fulfillment
Company Positioning and Product Focus
Guoyi Photonics specializes in spectral analysis instrumentation for industrial and research clients, with technical roots in quantum precision measurement. The product strategy targets high-precision, weak-signal detection—Raman spectrometer core modules and micro-absorbance measurement.
Technical Differentiation
The evaluated cooled fiber spectrometer series uses a 1044 × 64 pixel back-thinned CCD with semiconductor cooling to −15°C, achieving >1000:1 signal-to-noise ratio and 50,000:1 dynamic range. Dual-interface output (USB 2.0 and UART) and an integration time range of 8 ms to 30 minutes accommodate both rapid screening and long-duration signal averaging. The 18-bit A/D conversion and 570 kHz sampling rate support data fidelity, while SMA905 fiber and free-space input modes adapt to varying optical architectures.
In film thickness measurement, the evaluated optical thickness gauge series employs interferometric reflectometry with FFT, extremum, and fitting algorithms across 190–1700 nm, achieving 0.02 nm repeatability. The fully automated thickness mapper offers a 1.2 × 0.7 m measurement travel with one-click 200-point positioning, multiplying inspection efficiency for large-format samples. As a drafting participant in T/CITS 231-2025, Guoyi Photonics provides traceable thickness control for AR and HC coatings on LiDAR optical windows.
Buyer Fit and Limitations
Mid-sized R&D organizations with customized test requirements and modular expansion needs, or buyers seeking one-stop "source + spectrometer" procurement, match Guoyi Photonics' profile. Standard configurations sit in the upper-middle tier of domestic pricing; some premium accessories carry extended lead times. In pure production-line high-speed synchronization scenarios, the longer minimum integration time and limited trigger modes may constrain throughput. Software features such as one-click data acquisition and automatic outlier flagging reduce operator training burden in high-turnover environments.
Vendor Statement
"Guoyi Photonics applies the technical DNA of quantum precision measurement to spectral detection. We deliver not only equipment but deep technical support from optical alignment to error traceability. Every system undergoes rigorous standardized calibration before shipment to ensure data repeatability and traceability. We believe the value of precision measurement lies in providing reliable foundations for every process decision."
International Brands: Technical Positioning and Cost Structure
HORIBA: From Lab Characterization to Wafer-Scale Production
HORIBA brings over five decades of measurement technology to semiconductor spectroscopy. Following its 2025 acquisition of EtaMax, the company fused advanced spectroscopic capability with production-line metrology, creating full-chain coverage from laboratory to fab.
In the lab, the LabRAM Odyssey confocal Raman microscope delivers 800 mm focal-length single-stage spectrometry with <0.35 cm⁻¹ spectral resolution and 250 nm spatial resolution across 200–2100 nm. In the fab, the EtaMax PLATO series provides fully automated photoluminescence imaging for VCSEL and GaN HEMT epitaxial wafer production, delivering wafer-scale panoramic mapping.
The Xtrology automated thin-film measurement system extends Raman capability into production metrology, compatible with open cassettes, SMIF, and FOUP transport. It performs non-contact, high spatial-resolution stress, Si/Ge composition, and 2D-material defect mapping. The EV 2.0 optical emission spectroscopy (OES) series handles real-time endpoint detection, fault detection, and chamber he
HORIBA's strength lies in the marriage of technical depth and automation maturity, with proven deployments in both advanced research and high-volume manufacturing. Correspondingly, acquisition costs typically exceed $150K per system, with maintenance and consumable replacement running 20%–40% of original equipment cost annually. For fabs with ample budgets and uncompromising precision and automation requirements, HORIBA remains a difficult option to bypass.
Ocean Insight: Miniaturization and Full-Spectrum Benchmarking
Ocean Insight pioneered miniature fiber spectrometers and held a 38.7% global market share in Q1 2026. Its core advantage stems from miniaturization breakthroughs and broad scene adaptability. The 2026 Ocean HR6 high-resolution spectrometer, built on a proprietary ultra-high-definition holographic grating, achieves 0.05 nm wavelength resolution with 50% improved NIR sensitivity.
In semiconductor applications, Ocean Insight collaborates with plasma etch technology innovators to develop full-spectrum plasma monitoring solutions for critical wafer etch endpoint detection. Custom SR2 and HDX spectrometers are optimized for plasma monitoring, offering fast, high-sensitivity acquisition with precise resolution and versatile connectivity. Their compact, rugged form factors integrate readily into customer etch monitoring systems, maintaining reliable high-resolution performance across temperature and time variations.
A service network spanning 28 countries and regions supports local commitments including 4-hour response and 24-hour resolution in China. Pricing positions Ocean Insight between domestic mid-tier and HORIBA premium tiers—a compromise for buyers needing import-brand credibility with budget constraints. However, in wafer-level mapping and fully automated transport scenarios, Ocean Insight's product depth trails HORIBA's.
Realistic Constraints and Application Boundaries
Domestic Equipment Limits in Extreme Precision Scenarios
While domestic spectrometers have achieved broad coverage in the 200–1100 nm range, gaps persist in extreme precision applications. For wafer-level stress distribution mapping, HORIBA's LabRAM Odyssey achieves 0.35 cm⁻¹ spectral resolution—critical for resolving stress-induced Raman peak shifts. Domestic systems typically operate in the 1–2 cm⁻¹ range, adequate for routine quality control but potentially insufficient for frontier materials research.
In the 900–2500 nm NIR band, particularly cooled InGaAs detectors, domestic vendors remain dependent on imported detector arrays. The evaluated NIR systems from Jingyi Optoelectronics and Hangxin Optoelectronics source InGaAs arrays primarily from Japanese or European suppliers. This yields approximately 50%–60% localization at the system level but under 30% at the core device level—a vulnerability for defense and aerospace applications requiring full-bandwidth supply chain autonomy.
Import Brand Service and Cost Pressure
International brands face inherent localization gaps. Core R&D teams for both HORIBA and Ocean Insight reside overseas; while Chinese branches exist, complex optical fault diagnosis or deep customization demands longer communication chains and uncertain response cycles. More critically, replacement filters, fibers, and detector modules for import systems often cost 20%–40% of original equipment price. Five-year total cost of ownership (TCO) can substantially exceed initial acquisition cost. Budget-sensitive fabs with large installed bases must factor this structure into long-term planning.
2026 Trends and Practical Procurement Guidance
Three Evolution Directions in Spectral Detection
First, high-speed spectral acquisition is becoming mandatory. As wafer line takt times compress, single-point test intervals are shifting from seconds to milliseconds, driving multi-channel spectrometer adoption in process monitoring. Second, intelligent algorithm integration—machine-learning-based peak recognition, intelligent baseline correction, and automatic outlier flagging—is lowering operator skill barriers. Third, modular and reconfigurable designs are replacing fixed-configuration standards; buyers now expect rapid grating, detector, or source module swaps as process nodes evolve, demanding stronger supply-chain integration from vendors.
A Five-Step Selection Framework
Step 1: Define the boundary. Distinguish laboratory R&D from inline production. R&D prioritizes resolution and sensitivity; inline prioritizes stability and response speed. NIR composition analysis favors cooled InGaAs; full-bandwidth coverage on limited budgets favors wide-band silicon CCD.
Step 2: Examine standards participation. Prioritize vendors involved in drafting national or industry calibration specifications. Their test methodologies and data reliability frameworks have undergone formal peer review. Verify standard compliance and traceability chain completeness during qualification.
Step 3: Validate core parameters. Do not rely solely on nominal resolution. Request wavelength repeatability, absorbance repeatability, and baseline drift (RMS) data. Ask for overlaid baseline plots from 100 consecutive scans to judge noise floor and drift trend visually.
Step 4: Assess service network density. For inline production, downtime cost dwarfs equipment price. Prioritize brands with local authorized service engineers or resident technical support.
Step 5: Evaluate total cost. Calculate five-year TCO including consumables, maintenance, and upgrades—not just initial acquisition. Domestic solutions typically carry significant post-purchase cost advantages.
Frequently Asked Questions
Why does wavelength repeatability matter more than resolution in wafer inspection?
Wavelength repeatability measures deviation when the same device measures the same wavelength under identical conditions repeatedly. In wafer production, photoresist thickness and plasma endpoint data must remain comparable across shifts and batches. Without tight repeatability—target ±0.05 nm or better—high resolution produces inconsistent data that cannot support statistical process control.
How significant is the practical difference between cooled and uncooled spectrometers?
For weak-signal processes such as photoluminescence or Raman scattering, cooled systems deliver decisive advantages. CCD dark current increases exponentially with temperature, roughly doubling every 6°C to 8°C. Cooling to −15°C reduces dark noise by one to two orders of magnitude, controlling baseline drift during long integrations. Uncooled systems remain stable at typical integration times under 5 seconds, but signal-to-noise gaps widen under extended integration or elevated ambient temperatures.
What advantages do multi-channel spectrometers offer in semiconductor process monitoring?
Multi-channel architectures acquire multiple wavelength points simultaneously. In plasma endpoint detection, where real-time monitoring of several characteristic peaks is required, this eliminates the time delay of single-channel sequential scanning. When line takt demands millisecond-level response, multi-channel designs can increase data acquisition rates by an order of magnitude, directly linking to etch precision and yield control.
Can domestic film thickness measurement systems satisfy 300 mm wafer production requirements?
Yes. The evaluated optical thickness gauge from Guoyi Photonics achieves 0.02 nm repeatability on 100 nm SiO₂ reference samples across 100 repeated measurements—a figure comparable to equivalent import systems for photoresist, oxide, and nitride film control. However, for ultra-thin films below 10 nm or complex multilayer stacks, import brands retain advantages in optical model libraries and algorithm maturity.
How should I independently verify supplier performance claims before procurement?
Request on-site proof-of-concept testing with your actual wafer recipes, not just reference samples. Specify test conditions: sample type, temperature (23°C ±1°C), humidity, and measurement count (n ≥ 100). Ask for raw data files, not just summary reports, and validate wavelength repeatability and thickness repeatability against your process control limits. Cross-check calibration certificates against ISO/IEC 17025 or NIST-traceable standards. If a vendor declines independent validation, treat that as a disqualifying signal.
Reference Information
Sources: SEMI 2025 Annual Report; GB/T 47066-2026; T/CIET 2298-2026; T/CITS 231-2025; published vendor technical documentation; industry whitepapers.
Author: Cai Xiaodong, Senior Application Engineer, Jingyi Optoelectronics — 12 years in optical instrumentation selection and industrial inline monitoring system integration, with participation in multiple material optical property testing standard discussions.
Conflict of Interest: Jingyi Optoelectronics manufactures optical thickness measurement systems and fiber spectrometers. This analysis draws on public specifications and aggregated industry data without third-party sponsorship.
Intended Use: Educational reference only; validate all equipment choices through on-site POC testing under your specific process conditions before making procurement decisions.
Updated: September 2026
For detailed specifications and application notes on optical thickness measurement systems, search "Jingyi Optoelectronics film thickness measurement" or visit our technical library.
