Buy "Golden Spec" 2D Substrates
Stop guessing with standard wafers. For 2D research, you need specific oxide thicknesses for visibility and high doping for conductivity. We have them in stock.
Best Sellers: 285nm Oxide + Back-Gate
These wafers allow you to see monolayers (purple/violet contrast) and use the substrate as a global back-gate (< 0.005 Ω·cm).
| Item ID | Size | Spec Highlights | Action |
|---|---|---|---|
| #1583 | 100mm (4") | P++ (Boron), 300nm Oxide, <0.005 Ω·cm | Buy Now |
| #3510 | 50.8mm (2") | P++ (Boron), 300nm Oxide, <0.005 Ω·cm | Buy Now |
| #1432 | 100mm (4") | Standard P-type, 300nm Oxide (Visibility Only) | Buy Now |
Note: 285nm is often listed as 300nm ± 5% in industry terms. Both provide excellent contrast for Graphene/MoS2.
Researcher Case Studies & RFQs
Microwells to Create Free-Standing 2D Materials
"We need silicon wafer pieces with spherical wells which have ~ 1 um diameter. Our aim is using such wells to create free-standing 2D materials for measuring their mechanical properties."
Assistant Professor | Reference #260344Sapphire Wafers for 2D Material Growth
"We are currently in search of sapphire substrates, specifically double-sided polished and fully transparent, for use as substrates in the growth of two-dimensional materials... we noticed available sizes are mainly 50mm and 100mm."
[Image of sapphire crystal structure] Doctoral Student | Reference #278810HOPG Substrates for Fabricating 2D Materials
"I'm looking to buy HOPG as a substrate for 2D materials. Could I have a quote for HOPG of size 10*10*0.5mm?"
PhD Candidate | Reference #255966Thermal Oxide for Growing 2D Materials
"We would like to make an order of '285nm SiO2 on Si' substrates for the growth of 2D materials. In fact, my colleague already contacted you and we learnt that 2 inch P(100) 1-10 ohm-cm SSP 500um with 285nm of oxide."
Assistant Professor | Reference #188309Photoemission Measurements (Defect Density)
"285nm oxide thickness desired... We do low temperature optical measurements and I've noticed that other SiO2/Si substrates can give fluorescence peaks that are due to defects. Can you quantify defect density in your wafers?"
Postdoc | Reference #209209WS2 and WSe2 2D Materials
"Please send me a quotation including... Bilayer Graphene on SiO2/Si (10 mm x 10 mm)... If you can provide other 2D materials, e.g. WS2 and WSe2, I am also interested."
PostDoc | Reference #215004Get a Custom Quote
Need custom alignment marks, 90nm oxide, or specific dicing?
Or, Buy Online and Start Your Research today!
Why These Specifications Matter
Success in 2D material synthesis and transfer relies heavily on the substrate. Here is why our "Golden Specs" are the industry standard:
1. The Visibility Factor: 285 nm SiO₂
A mono-layer of graphene is only 0.34 nm thick and transparent. You cannot see it on bare silicon. However, on 285 nm (or 90 nm) of SiO₂, light interference effects change the color of the substrate where the flake sits. This creates a high-contrast violet/purple shift, allowing you to locate flakes with a simple optical microscope.
2. The Back-Gate Factor: Degenerate Doping
To measure the electrical properties of your material (e.g., MoS₂ or Graphene FETs), you need a gate electrode. By using Degenerately Doped Silicon (Resistivity < 0.005 Ω·cm), the entire silicon wafer acts as a conductive "Back Gate".
- Simplify Fabrication: No need to deposit and pattern a local metal gate.
- High Breakdown: Thermal oxide offers superior dielectric strength compared to CVD oxide.
Which Substrate for Which Process?
For Exfoliation (Scotch Tape Method):
Use Prime Grade silicon wafers (Item #1583). Surface roughness is critical; any roughness reduces the Van der Waals contact area and lowers your yield.
For CVD Synthesis (Growth):
Use Thermal Oxide or Fused Silica. Avoid cheap CVD-oxide wafers, which can outgas or crack at growth temperatures (700°C–1000°C).
What is 2D Materials Exfoliation?
2D materials exfoliation refers to a process used to create thin, two-dimensional layers from bulk materials. There are two main types:
- Mechanical Exfoliation: Also known as the "Scotch tape" technique, this method peels layers off bulk crystals (like Graphite or MoS2) to produce high-quality flakes.
- Liquid-Phase Exfoliation: Bulk materials are dispersed in solvent and subjected to ultrasonication. This produces larger quantities but with less control over thickness than mechanical exfoliation.
Best Silicon Wafer Specs for Thin 2D Growth
Choosing the best wafer depends on your specific 2D material, but general guidelines include:
- Orientation: (100) is standard for graphene; (111) may be used for specific epitaxial matches.
- Oxide Layer: 285nm is the standard for optical contrast, though 90nm is also used.
- Surface Roughness: < 5 Angstroms (Prime Grade) is essential for uniform growth and adhesion.
- Thermal Stability: For CVD temperatures (>800°C), thermal oxide or Fused Silica/Quartz is required to prevent outgassing.
Common 2D Materials We Support
- Graphene: The standard for back-gated transport studies.
- TMDs (MoS₂, WS₂): Requires clean surfaces to minimize scattering.
- h-BN: Often transferred onto our SiO₂/Si wafers as a dielectric spacer.
- HOPG: Highly Oriented Pyrolytic Graphite substrates available for STM calibration and exfoliation.