Substrates used for SU8 

SU-8 photoresist is a versatile negative epoxy-based resist widely used in microfluidics, MEMS fabrication, biosensors, lab-on-a-chip devices, PDMS mold fabrication, biomedical engineering, and semiconductor research. Researchers commonly use silicon wafers, Borofloat 33 glass, BK7 glass, and ITO-coated glass substrates for SU-8 lithography because they provide excellent adhesion, dimensional stability, and high-resolution pattern transfer. Whether creating microchannels, master molds, flexible substrates, or advanced MEMS structures, selecting the proper SU-8 compatible substrate is critical for achieving reliable and reproducible fabrication results.

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SU-8 Compatible Substrates for Microfluidics, MEMS, and PDMS Mold Fabrication

SU-8 photoresist is one of the most widely used negative photoresists for microfluidics, MEMS fabrication, biosensors, lab-on-a-chip devices, PDMS mold production, and biomedical research. Selecting the proper substrate is essential for achieving strong SU-8 adhesion, precise pattern transfer, high aspect ratio structures, and reliable device performance.

UniversityWafer supplies silicon wafers, glass wafers, Borofloat 33 glass, ITO coated glass wafers, and other substrates commonly used for SU-8 lithography and microfabrication applications.

Silicon Wafers for Strong SU-8 Adhesion

A postdoctoral researcher requested the following quote:

I need silicon wafers for fabrication of master molds used in microfluidic device fabrication. Strong adhesion between SU-8 and the substrate is important. Are your wafers suitable for this application? Please provide pricing for 4-inch, 600 µm thick silicon wafers.

Reference #212365 for specifications and pricing.

For many SU-8 applications, polished silicon wafers are preferred because they provide excellent surface quality, dimensional stability, and compatibility with photolithography processes. Silicon wafers are commonly used as master molds for PDMS casting, microchannel fabrication, and MEMS device development.

What Substrates Are Used to Make SU-8 Masks?

A PhD candidate requested the following quote:

Could you provide pricing for 1-inch and 2-inch silicon wafers used to fabricate SU-8 masks? Double-side polishing and specific doping levels are not required. Please recommend suitable wafers for this application.

Reference #268867 for specifications and pricing.

Researchers frequently use low-cost silicon wafers, mechanical-grade wafers, and polished silicon substrates for SU-8 mask fabrication because electrical properties are often less important than flatness, cleanliness, and photoresist adhesion.

Borofloat 33 Glass for SU-8 Microfluidic Devices

A university laboratory requested Borofloat 33 glass wafers for SU-8 microfluidic device fabrication.

We are interested in purchasing Borofloat 33 glass wafers for manufacturing SU-8 microfluidic devices. Please provide pricing for 50.8 mm and 76.2 mm diameter substrates.

Borofloat 33 glass is commonly selected for optical microfluidics, biomedical devices, lab-on-a-chip systems, and MEMS because of its excellent thermal stability, optical transparency, and chemical resistance.

Get Your SU-8 Substrate Quote FAST! UniversityWafer supplies silicon wafers, Borofloat 33, glass wafers, ITO-coated glass, and custom substrates for SU-8 lithography, microfluidics, PDMS mold fabrication, MEMS, and biomedical research.

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Why Researchers Choose SU-8 Compatible Substrates

  • Excellent SU-8 adhesion and pattern fidelity
  • High-resolution photolithography performance
  • Suitable for PDMS mold fabrication
  • Compatible with MEMS and NEMS processes
  • Ideal for microfluidic channel fabrication
  • Good thermal and chemical stability
  • Supports biosensor and biomedical device development
  • Available in silicon, glass, Borofloat, and ITO-coated materials

SU-8 Adhesive Bonding for Silicon and Glass Wafers

SU-8 photoresist is often used as an adhesive, structural layer, or patterned material for bonding silicon wafers to glass wafers, fabricating microfluidic devices, and producing master molds for PDMS casting. Because SU-8 is an epoxy-based negative photoresist, it can form thick, high-aspect-ratio structures that are useful for MEMS, lab-on-a-chip devices, biosensors, flexible substrates, and biomaterials research.

How to Bond Silicon to Glass Wafers Using SU-8

Researchers often use SU-8 to bond silicon and glass substrates when fabricating multilayer microfluidic devices or dicing bonded wafer stacks. Bonding success depends on substrate material, surface cleanliness, curing temperature, applied pressure, glass type, thermal expansion mismatch, and dicing method.

A government scientist asked about bonding ITO-coated glass wafers to silicon using SU-8 adhesive:

The researcher bonded ITO coated glass wafers to silicon wafers using SU-8 at elevated temperature and pressure. The bonded wafers were then diced with a dicing saw, but the glass cracked during cutting. The scientist asked whether Borofloat glass, BK7 glass, or another ITO-coated substrate would be better suited for the process.

UniversityWafer, Inc. Answer: The ITO coated substrates were made from LCD display grade float glass, which is different from Borofloat 33 glass. For some ITO glass substrates, cutting completely through the glass is not always required; a light surface scribe may allow the glass to separate more easily. Borofloat 33 or BK7 glass may be more suitable when improved thermal stability, mechanical strength, or optical quality is required.

What Is SU-8 Passivation?

SU-8 passivation is the use of cured SU-8 photoresist to protect surfaces, isolate device structures, improve chemical resistance, or reduce unwanted reactions with biological and chemical environments. In MEMS, NEMS, biosensors, and microfluidic systems, SU-8 can function as both a structural material and a passivation layer.

Passivated SU-8 structures are useful for reducing leakage, improving device stability, protecting microchannels, and extending the operating life of microfabricated devices. SU-8 is especially common in biomedical devices, cell culture platforms, lab-on-a-chip systems, and polymer-based microfluidics.

SU-8 Photoresist for PDMS Mold Fabrication

SU-8 is widely used to create master molds for PDMS molds because it can produce thick, well-defined negative photoresist patterns. These SU-8 structures allow researchers to cast PDMS replicas for microchannels, biomaterials research, tissue engineering, and human cell culture devices.

A PhD candidate requested mechanical-grade silicon wafers with SU-8 3010 photoresist treatment to create structures greater than 10 µm thick for repeated PDMS casting and biomaterial production.

For repeated PDMS casting, researchers often choose thicker or mechanically stable substrates such as mechanical-grade silicon wafers, 100 mm silicon wafers, or 125 mm silicon wafers. Surface quality, wafer flatness, SU-8 adhesion, and curing conditions all affect mold durability.

Substrates Used for SU-8 Flexible Devices

SU-8 can also be used to fabricate flexible substrates and polymer-based microstructures. Biomedical researchers use SU-8 wafer templates to create flexible devices for cell culture, biomaterial testing, microfluidics, and sensor development.

Buy Item #2564 online or reference #0208161 for specifications and pricing.

What Silicon Wafer Is Suitable for SU-8 Lithography?

For SU-8 lithography, researchers commonly select 4-inch or 6-inch silicon wafers with a clean polished surface. In many SU-8 mask or mold applications, dopant type is not critical, but wafer diameter, thickness, surface polish, flatness, and cleanliness can affect photoresist coating uniformity and pattern quality.

An international PhD scientist requested 50 pieces of 4-inch silicon wafers suitable for SU-8 lithography, with possible additional 6-inch wafers for AZ positive photoresist lithography.

Reference #268687 for specifications and pricing.

Best Substrates for SU-8 Applications

  • Silicon wafers for SU-8 lithography, MEMS, molds, and microfluidics
  • Borofloat 33 glass for thermal stability and optical applications
  • BK7 glass for optical-quality wafer bonding and device fabrication
  • ITO coated glass for conductive transparent substrates
  • Mechanical-grade silicon wafers for lower-cost PDMS mold development
  • Thick silicon wafers for repeated PDMS casting and mold durability

Related SU-8 & Microfabrication Resources

UniversityWafer supplies SU-8 compatible silicon wafers, glass wafers, Borofloat 33, BK7, ITO coated glass, and custom substrates for microfluidics, MEMS, PDMS molds, SU-8 lithography, and biomedical research.