Fused Silica Wafers

CQT uses a variety of glass and quartz depending on the application and material requirements. Our designers and engineers are skilled at working with any number of glass and quartz materials to machine and fabricate precision optical products such as fused quartz parts for optics, fused silica parts used in fiber optic applications

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Brief Introduction

Fused silica wafers product introduction

Fused silica wafers are highly valued in various optical applications due to their exceptional properties. These wafers come in different grades, each tailored for specific uses, such as deep ultraviolet (DUV) and infrared (IR) applications.

DUV Grade Fused Silica Wafers

The UV grade fused silica wafers are made from fully synthetic materials with very low trace metal content, produced using the Synthetic Chemical Vapor Deposition (CVD) method. This process ensures the wafers have high purity and excellent optical properties. Fused silica is highly resistant to heat and exhibits a broad transmission range, with more than 85% transmission at 185 nm and over 90% from 200 nm to 2000 nm. Common brands and grades for UV grade fused silica include JGS1, Corning 7980, and SK1300. CQT Group supplies these wafers with diameters up to 8 inches (200 mm) and a surface roughness (Ra) of less than 0.5 nm, making them ideal for precision optical applications where minimal surface defects are crucial.

IR Grade Fused Silica Wafers

IR grade fused silica wafers are designed for applications requiring high transmission in the infrared range, typically from 185 nm to 3500 nm. These wafers have very low hydroxyl (OH) content, usually less than 5 ppm, which minimizes absorption in the IR region. The electrical melting method is used to produce IR grade fused silica, ensuring a high level of purity and consistency. Common brands and grades for IR grade fused silica include JGS3, Corning 7979, and SK1310. CQT Group supplies these wafers with diameters up to 8 inches (200 mm) and a surface roughness (Ra) of less than 0.5 nm, making them suitable for high-precision IR optical components and applications where low OH content is essential for performance.

Parameter	JGS1	JGS3
Maximum Size	<Φ250mm	<Φ200mm
Transmission Range	0.17~2.10um	0.25~3.50um
(Medium transmission ratio)	(Tavg>90%)	(Tavg>85%)
OH- Content	1200 ppm	5ppm
Fluorescence (ex 254nm)	Virtually Free	Strong v-b
Impurity Content	5 ppm	40-50 ppm
Birefringence Constant	2-4 nm/cm	4-10nm/cm
Melting Method	Synthetic CVD	Electrical melting
Applications	Laser substrate:Window,lens,prism, mirror, etc.	IR substrate
Applications	Laser substrate:Window,lens,prism, mirror, etc.	IR substrate

Product Parameters

Fused silica wafers process capability

The general specs are as follows sheet, if your specified is not included with it, you may freely tell us and we’ll pleased to customize them for you.

spec	unit	4"	6"	8"	10"	12”
Diameter/size(or square)	mm	100	150	200	250	300
Tolerance (±)	mm	0.2	0.2	0.2	0.2	0.2
Thickness	mm	0.10 or more	0.30 or more	0.40 or more	0.50 or more	0.50 or more
Primary reference flat	mm	32.5	57.5	Semi-notch	Semi-notch	Semi-notch
LTV (5mmx5mm)	µm	< 0.5	< 0.5	< 0.5	< 0.5	< 0.5
TTV	µm	< 2	< 3	<3	<5	<5
Bow	µm	±20	±30	±40	±40	±40
Warp	µm	≤ 30	≤ 40	≤ 50	≤ 50	≤ 50
PLTV(5mm*5mm)<0.4um	%	≥95%	≥95%	≥95%	≥95%	≥95%
Edge Rounding	mm	Compliant with SEMI M1.2 Standard/refer to IEC62276
Surface Type		Single Side Polished /Double Sides Polished
Polished side Ra	nm	≤1
Back Side Criteria	µm	general 0.2-0.7 or customized

Applications of Fused Silica Wafers

Fused silica wafers are essential across a wide range of industries:

1. Semiconductor Manufacturing

Photomask substrates

Wafer carriers and process components

Etching and deposition equipment parts

2. Optical and Photonic Systems

Lenses, windows, and prisms

Laser optics and beam delivery systems

Optical coatings and substrates

3. UV and Deep-UV Applications

Lithography systems

UV transmission optics

Sterilization and analytical equipment

4. High-Temperature Environments

Furnace components

Thermal shielding and insulation materials

5. Scientific Instruments

Spectroscopy and microscopy components

Precision measurement devices

Advantages Over Crystalline Quartz

While both fused silica and crystalline quartz share the same chemical composition (SiO₂), their structural differences lead to distinct advantages:

Isotropic properties (no directional dependence)

No piezoelectric effect (ideal for optical and insulating applications)

Higher optical uniformity and lower birefringence

Better performance in extreme thermal environments

These characteristics make fused silica the preferred choice for optical and semiconductor uses, while crystalline quartz is favored for piezoelectric applications.

Key Specifications to Consider

When selecting fused silica wafers, important parameters include:

Purity level (ppm of impurities)

Optical transmission range

Surface roughness and flatness

Thickness and diameter tolerances

Thermal and mechanical properties

Custom specifications are often required for advanced industrial and research applications.

Future Trends and Innovations

With the rapid advancement of semiconductor and photonics technologies, fused silica wafers continue to evolve:

Ultra-flat wafers for advanced lithography

Enhanced UV transmission for next-generation chip fabrication

Integration with photonic integrated circuits (PICs)

Improved purity for quantum and laser applications

Conclusion

Fused silica wafers are a cornerstone material in modern high-tech industries, offering unmatched optical clarity, thermal stability, and chemical resistance. Their versatility and reliability make them essential for semiconductor processing, optical systems, and scientific instrumentation.

As technology continues to push the boundaries of precision and performance, fused silica wafers will remain a critical material driving innovation across optics, electronics, and advanced manufacturing.