Objective: Osmium Plasma Coater (OPC) is the plasma coating device that uses the DC glow discharge method to coat conductive thin film mainly for SEM samples.

No charging. No grains. No heat damages.
An ultimate solution to obtain clear SEM images.

The Osmium Plasma Coater is a kind of plasma CVD coater which is utilizing a method for coating samples in the negative glow phase domain of DC plasma discharging. As conventional types of metal coaters, there are various kinds of so called sputter coater which use the heavy metals as coating material, such as gold, platinum, palladium etc.
With these methods, the problem of granularity of coating itself is inevitable by any means. Also, if examined at high magnification, the specimens coated by these methods can not avoid charging, heat damage and contamination caused by exposure to strong electron beam with SEM, resulting in lower resolution of SEM image.
A gas reactor in which the anode and cathode plates are placed vertically is evacuated to a high vacuum, then sublimated osmium tetroxide (OsO4) is introduced, and a DC glow discharge is generated under certain conditions, while maintaining a predetermined gas pressure. The osmium metal molecules excited by the collision of electrons instantaneously become plasma between the two electrodes. In particular, in the negative glow phase domain, there is strong light emission due to the fierce diffusion of the concentrated positively ionized metal molecules. As a result, on the surface of the specimen placed in this negative glow phase, the positive ion metal molecules uniformly adhere to the specimen surface and form a perfectly amorphous metal coating of molecular level, which molds the micro-structure of the specimen surface faithfully.

Principle:  A small amount of osmium tetroxide(OsO4)gas / naphthalene gas(C10H18) is introduced into the small gas reaction vessel that equips with an anode plate and a cathode plate.
Then, in the gas reaction vessel, when a DC glow discharge is generated under a thin sublimation gas pressure, the osmium metal molecules excited by the collision of electrons instantaneously become plasma between the two electrodes. The positive column and the negative glow phase are separated, and the blue-violet light of the negative glow phase emits.
At the same time, the positive ion metal molecules instantly adhere to the surface of the specimen, which is placed in the negative glow phase area on the cathode plate, and an osmium metal thin film/plasma-polymerized film(naphthalene) is formed. With an osmium metal thin film on the surface of the SEM specimen, an extremely clear image can be obtained.  


Osmium thin film: 

 • Conductive thin film for SEM specimen
• Prevention of contamination for SEM/TEM specimen
• Protective film for AFM specimen
• Conductive protective film for SPM specimen
• Protective film for SPM cantilever

Plasma-polymerized film (naphthalene): 

• Protective film for FIB specimen
• Prevention for peeling sample from embedding resin
• Coating for fluorine resin (Os-PF hybrid coating)
• Support film for TEM grid
• Drift prevention for ultra-thin sections for TEM

Osmium ultra-thin film [optional]:

• Observation of the ultrafine structure of insulators by FESEM
• Quantitative analysis of top surface of insulators by ESCA/AES
• Enhancement of conductivity for TEM specimen
• Static prevention treatment for AFM specimen
• Antistatic treatment for STM specimen
• Etching (Mixed gas method only)

Hydrophilizing treatment [optional]:

• Pre-hydrophilization treatment for osmium coating on fluoro resin surface etc.
• Prevention for peeling sample from embedding resin
• Hydrophilization of the support film surface for TEM
• Hydrophilization of grids for TEM
• Hydrophilization of a diamond knife for ultramicrotome
• Improvement of wettability
Deep well electrode [optional]:
• Coating for samples with a height
Multiple safety measures provide operator
protection from OsO4 exposure.


Osmium film:
No grains:
 amorphous metal coating is formed
No heat damage: coating is proceed under room temp.
No electron beam damage: the melting temperature of Osmium is 2700 deg C
No contamination: coating is started from vacuum state Plasma-polymerized film (naphthalene):
Strong film: withstand the gallium ions beams used in FIB
Heat resistant and insulated film
No grains: amorphous metal coating is formed
No heat damage: coating is proceed under room temp.
No electron beam damage
No contamination: coating is started from vacuum state


Automatic: whole process is completed just by pressing START button after settings
Intuitive: coating thickness is controlled by thickness setting, not by discharge time
Short coating time: a few nm/a few seconds
Easy to exchange Os ampoule: detachable reservoir, observation window (for checking of remaining amount of Os) and built-in ampoule cutter on reservoir


Fully automated: reduce chance of human error
Safety features on Os reservoir: gas port integrated locking pin and built-ion ampoule cutter
Interlocking system with reaction chamber: unable to open the chamber unless OsO4 is exhausted, unable to introduce OsO4 when the chamber open
Fail safe to prevent Os leak at power down
Osmium absorption filter: not require any ventilator

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