Silicon Nitride Window

The fabrication of silicon nitride free-standing membranes is carried out entirely in a cleanroom environment. A low-stress silicon nitride film is first deposited on the silicon substrate using a low-stress LPCVD process. Subsequently, the silicon on the backside of the wafer is removed through wet etching until the silicon beneath the window area is completely etched away. These silicon nitride membrane windows are widely used in TEM imaging, infrared and ultraviolet spectroscopy research, biomedical applications, and related fields.

Applications of Silicon Nitride Free-standing Membranes

TEM sample support membranes

X-ray observation windows

Chemically inert and high-temperature-resistant substrates for in-situ sample processing and subsequent observation

Vacuum isolation windows/chambers

Nanopore DNA sequencing

Features of Silicon Nitride Free-standing Membranes

High chemical stability

High mechanical strength

Excellent X-ray transparency

Capable of withstanding temperatures up to 1000°C

High surface flatness (surface roughness < 1 nm)

Excellent hydrophilicity after plasma treatment

Existing AEMD Standard Samples

Deposition Method: Low-stress LPCVD furnace depositionSilicon Nitride Film Thickness: 100 nm

Membrane Stress Level: <100 MPa (tensile)

Refractive Index: 2.2 ± 0.05

Window Size: 52 × 52 μm

Frame Thickness: 200 μm

Outer Dimensions: 2.5 × 2.5 mm

Customization Services Available from AEMD

Silicon nitride membrane windows can be fabricated on substrates with different crystal orientations, including (100), (110), and (111).

Users may request customization based on:

Substrate thicknesses ranging from 200 μm to 600 μm

Silicon nitride film thicknesses ranging from 20 nm to 200 nm

Different window sizes such as 30 × 30 μm, 50 × 50 μm, and 100 × 100 μm

Low-stress silicon nitride TEM windows can also be processed using FIB drilling to create nanopores with diameters of 50 nm or larger.

For additional requirements, please contact the process engineer.