in 


Grids Overview
Silicon Dioxide Support Films for TEM

PELCO® Silicon Dioxide Support Films for TEM

Product Overview and Manufacturing Details

Manufacturing Method

The PELCO® Silicon Dioxide films are manufactured using the latest, patented, state-of-the-art semiconductor and MEMS manufacturing techniques. The amorphous, thermal SiO2 is grown on a 200um thick silicon wafer to the desired thickness of 40, 18 or 8nm. A 200nm silicon nitride film is grown on top of that. The specimen viewing area is created by etching away a window in the silicon substrate. Apertures are etched into the silicon nitride leaving a support mesh for the silicon dioxide. The combination of stress and compression in the two layers produce the PELCO® silicon dioxide films with its superior flatness. After finishing the etching process, the individual frames with the membranes are lifted from the wafer.

Window sizes and shapes

Single window of 0.5 x 0.5mm with silicon nitride support mesh creating 24 apertures. Due to the structure of the silicon and the etching process, the window in the silicon substrate is etched with a 35 angle, leaving a larger 0.78 x0.78mm opening at the back side of the frame.

Silicon Dioxide Support Film Drawing


40nm Membrane Thickness

40nm silicon dioxide support filme back side
Back Side
 40nm silicon dioxide support filme cross section

40nm back side silicon dioxide support film

Front Side


18nm Membrane Thickenss

18nm membrane thickness silicon dioxide support film 18nm silicon dioxide support film cross section 18nm  silicon dioxide support film front side

 


8nm Membrane Thickness

8nm silicon dioxide support film back side 8nm silicon dioxide support film cross section 8nm silicon dioxide support film front side


Manufacturing Tolerances
Frame Thickness: 200µm ±15µm
Membrane Thickness: 40nm ±4nm
18nm ±3nm
8nm ±2nm
Mesh Thickness: 200nm ±10nm
Frame Diameter: 3.0mm ±0.05mm
Window Dimensions: 500 x 500µm ±20µm

Debris free products

Handling capabilities and smoothness of the edges are design advantages over other brands of silicon dioxide or silicon nitride support films. The PELCO® silicon Dioxide support films are manufactured like TEM grids with a 3mm diameter using a unique and patented manufacturing process. They have no broken edges, are circular and the membranes are completely free from debris particles. The mechanical and thermal stability allow for cleaning or treating of the silicon dioxide support films with chemicals (solvents, acids and bases) glow discharge or plasma cleaning. It is recommended that ultrasonic cleaning is not to be used, as it can easily shatter the thin silicon dioxide support films.