Gold Coated Glass Slides and Silicon Wafers

Topics Covered

Gold Coating Introduction
Glossary of Terms
Gold Coating Methods
Critical Features
Highlights of Gold Substrates
Platypus Gold Coated Substrates
Platypus Gold Substrates
Custom Gold Substrates
Template Stripped Gold Chips
     AFM Characterization
     Goniometer Characterization
About AMSBIO

Gold Coating Introduction

A gold coating is a very thin film of gold deposited onto a supporting substrate. This serves as a very useful substrate in the life science academia & industrial markets.

Typical characteristics of gold surfaces include:

  • Good resistance to oxidation
  • Inert surface for use with biological experimentation
  • Good conductor of electricity
  • Ultra smooth surfaces can be prepared
  • Easily forms thiol chemistry self-assembled monolayers (SAM)

Glossary of Terms

Nanometer (nm): 1x10-9 m

Ångström (Å): 0.1 nm

E-beam Evaporation: A physical vapor deposition technique used for thin film coatings.

Adhesion Layer: A thin layer deposited for improving the adhesion of gold on to the substrate (material to be coated).

Roughness: A measure of surface smoothness.

Grain Size: The size of gold grains present on the surface. Grain size has an effect on the roughness of the gold surface.

Self Assembled Monolayers(SAM): Surfaces consisting of a single layer of molecules on a substrate, prepared by adding a solution of the desired molecule onto the substrate surface and washing off the excess.

Gold Coating Methods

Physical vapor deposition (PVD) techniques are commonly used for depositing metal thin films onto a surface. Common PVD techniques include:

  • Thermal vapor deposition: The material to be deposited is evaporated by electrical resistive heating at low pressure and is condensed onto the substrates.
  • Sputtering: The material to be deposited is ejected from a source by plasma discharge which is then deposited onto the substrates.
  • Electron-beam vapor deposition: The material to be deposited is heated to a high vapor pressure by electron beam bombardment in an ultra-high vacuum and is condensed onto the substrates.

Critical Features

Adhesion layer: A thin layer of metal (15-50 Å of titanium or chromium) that is deposited onto the substrate to improve adhesion of the gold layer.

Thickness of gold layer: For most applications a 100-1000Å thick gold thin film is deposited on substrates. Thickness of gold is an important parameter in applications that use different optical techniques.

Roughness: A root mean square (RMS) roughness < 40Å is desired for most applications. However, for certain scanning probe applications a lower roughness is required.

Surface purity: A clean surface is required for applications that employ gold surface modifications. Depending on the PVD process used, level of vacuum in the system, original purity of the gold source, and history of metals used in the particular system the level of gold thin film purity can vary greatly.

Highlights of Gold Substrates

Ultra Clean Substrates – Substrates are cleaned by oxygen plasma prior to coating to promote adhesion and cleanliness.

Dedicated E-beam CoaterAMSBIO uses an electron beam evaporator dedicated to the deposition of titanium and gold to ensure that the gold thin films on the substrates are as pure as possible.

Cleanroom Facility – The gold coatings are applied in a class 10,000 cleanroom to reduce particulate contamination of the substrates.

High Reproducibility – Dedicated gold coating equipment, a 99.999% pure gold source, calibrated deposition control, and consistent quality control measurements all contribute to the high reproducibility of Platypus’ gold coated substrates.

Titanium Adhesion Layer – Titanium is a better adhesion layer than Chromium; Chromium is able to diffuse into the gold layer faster and contaminate it.

Low RMS Roughness – Roughness of AMSBIO’s gold coated substrates will depend on the thickness of gold and type of substrate it is on, but generally the RMS roughness is between 1.5 and 4nm.

Custom Coatings – amsbio can work with customers to coat custom substrates and/or specified titanium and gold thicknesses

Platypus Gold Coated Substrates

Gold Coated microscope slides

Gold coated round coverslips

Gold coated square coverslips

Gold coated silicon wafers

Platypus Gold Substrates

Product # Product Description Package Size
AU.0100.ALSI Aluminosilicate Glass Slides Coated with 20A Ti/100A Au 1" x 3" x 0.7 mm 5 slides
AU.0500.ALSI Aluminosilicate Glass Slides Coated with 25A Ti/500A Au 1" x 3" x 0.7 mm 5 slides
AU.1000.ALSI Aluminosilicate Glass Slides Coated with 50A Ti/1000A Au 1" x 3" x 0.7 mm 5 slides
AU.0100.CSS Coverslips Coated with 20A Ti/100A Au 22 mm square, 0.13 to 0.16 mm thickness 12 coverslips
AU.0500.CSS Coverslips Coated with 25A Ti/500A Au 22 mm square, 0.13 to 0.16 mm thickness 12 coverslips
AU.0100.CSR Coverslips Coated with 20A Ti/100A Au 15 mm round, 0.13 to 0.16 mm thickness 24 coverslips
AU.2000.MC1 Mica Coated with 2000A Au (small); 1" x 1.5" mica 1 piece
AU.2000.MC2 Mica Coated with 2000A Au (large); 1" x 3" mica 1 piece
AU.1000.SL1 Silicon Wafers Coated with 50A Ti/1000A Au 4" diameter, 525 um thickness 3 wafers
AU.1000.SL2 Silicon Wafers Coated with 50A Ti/1000A Au 4" diameter, 525 um thickness 12 wafers

Custom Gold Substrates

AMSBIO can work with customers to coat custom substrates and/or specified titanium and gold thicknesses for their particular application

Custom Coating Features Platypus' Capabilities
Substrate Dimensions Minimum Size = 1cm x 1cm square
Maximum Size = 6.5" x 6.5" square
Substrate Thickness 0.1mm - 3 mm
Substrate Type A vacuum-compatible material (to 10-7Torr)
Thickness of Gold Coating Minimum = 0 Angstroms
Maximum = 3000 Angstroms
Note: less than 75 Angstroms of Au may not give a continuous coating and is therefore, not recommended.
Thickness of Titanium Coating Minimum = 0 Angstroms
Maximum = 500 Angstroms
Note: 15 - 50 Angstroms of Ti is recommended for an adhesion layer between the substrate and the Au layer.
Note: If solely coating Titanium, less than 75 Angstroms may not give a continuous coating and is therefore, not recommended.
Photolithography Patterning Available for greater than 300 μm features
Note: Please contact Platypus with your exact application to evaluate our capability to perform to your specifications.

Template Stripped Gold Chips

Template Stripped Gold Chips provide an extremely smooth and clean gold surface for a variety of research needs, including AFM and SEM applications, biosensor development, and SAMs studies.

AFM Characterization

Representative data of RMS roughness over a randomly selected 1 um2 area on gold surfaces.

Goniometer Characterization

Representative data of water static contact angle on gold surfaces.

Surface Condition Static Contact Angle
As-Deposited Gold (fresh) 25 - 40°
As-Deposited Gold (after exposure to atmosphere for 5 hours) 75 - 90°
Template Stripped Gold Chip (stripped prior to reading) 25 - 40°

Note: All measurements taken at ambient temperature

About AMSBIO

AMSBIO’s mission is to be a profitable premier provider of quality life science research reagents and services helping customers develop innovative methods, processes, products and medicines.

This is achieved by offering small and medium size manufacturers, academic groups and revenue generating biotechs a unique partnership for the global market and by providing state of the art and cost effective solutions to end users and partners.

Source: AMSBIO.

For more information on this source, please visit AMSBIO.

Date Added: May 17, 2013 | Updated: Jun 11, 2013
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