Corning HPFS® 7979, 7980 & 8655 Fused Silica

Original Manufacturer Reference · Corning · High-purity fused silica

Product Overview

Non-crystalline high-purity fused silica grades differentiated by OH content, inclusion and homogeneity classes, birefringence and UV/IR transmission performance.

Typical Applications

UV/DUV and IR optical components
Semiconductor lithography and metrology
High-temperature, low-expansion windows and wafers

Reference Specifications

The following values are condensed from the supplied manufacturer data sheet. Test conditions are retained where they affect interpretation.

HPFS 7979 IR grade	OH <1 ppm; metallic impurities <100 ppb; birefringence ≤5 nm/cm; inclusion classes 0/1/2
HPFS 7980 standard	OH 800–1000 ppm; metallic impurities <1000 ppb; birefringence ≤5 nm/cm; inclusion classes 0–5
HPFS 7980 KrF grade	OH 800–1000 ppm; metallic impurities <500 ppb; birefringence ≤1 nm/cm; transmission ≥99.90%/cm at 248 nm
HPFS 7980 ArF grade	OH 800–1000 ppm; metallic impurities <100 ppb; birefringence ≤1 nm/cm; transmission ≥99.50%/cm at 193 nm
HPFS 8655 ArF grade	OH <1 ppm; metallic impurities <10 ppb; birefringence ≤1 nm/cm; transmission ≥99.75%/mm at 193 nm
Density / Young’s / shear modulus	2.20 g/cm³ / 73 GPa / 31 GPa
Poisson’s ratio / Knoop hardness	0.16 / 522
CTE	0.52 × 10⁻⁶/°C at 5–35°C; 0.57 × 10⁻⁶/°C at 0–200°C
Softening point	7980: 1585°C; 7979 and 8655: 1627°C
Representative refractive index	About 1.4570 at 632.99 nm, grade dependent

China-Made Alternative Products

For a China-made fused-silica substitute, grade selection is based on spectral band, OH level, metallic impurities, inclusion/bubble class, refractive-index homogeneity, birefringence, laser-damage requirement and thermal history. These criteria are more reliable than matching only the generic name ‘quartz’.

Recommended matching criteria:

Chinese high-purity fused silica for UV, IR and thermal use
Wafer, window, plate and custom geometry
COA, spectral and sample-level qualification

Target modelCritical parametersCandidate gradeSample testingBatch qualification

Customization and Processing

Round wafers, square panels, windows and custom outlines
Precision cutting, edge grinding, chamfering and laser processing
Single- or double-side polishing, thinning, cleaning and marking
TTV, warp, roughness, dimensional and optical inspection to agreed criteria

Qualification Note

Important: “Alternative” means a candidate selected for the same application target. It does not mean an automatic drop-in replacement or identical composition. Final acceptance is based on agreed specifications, samples, test reports and process verification.

Request Material Matching

Manufacturer and product names are used only to identify reference materials and technical targets. Semicon Global Tech is an independent supplier and does not claim manufacturer authorization unless explicitly stated. Original-grade data and China-made alternative specifications are presented separately; supply specifications are confirmed by quotation, COA and approved samples.

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