Ashing
Encyclopedia
Depending on context, ashing may refer to plasma ashing
, which is used in semiconductor manufacturing and microelectromechanical systems
for removing photoresist
, or it may refer to the process below:
A test to deduce the amount of ash forming material present in a petroleum product so as to decide its use in certain applications. Ash-forming materials are considered to be undesirable impurities or contaminants.
The specimen is placed in a suitable vessel, evaporating dish
or crucible
and ignited. It is allowed to burn until only ash and carbon remains. The carbonaceous residue is reduced to ash by heating in a muffle Furnace
at about 775oC, cooled and weighed.
Ashing is also performed prior to chemical analysis by inductively coupled plasma emission spectrometry.
Plasma ashing
In semiconductor manufacturing plasma ashing is the process of removing the photoresist from an etched wafer. Using a plasma source, a monatomic reactive species is generated. Oxygen or fluorine are the most common reactive species...
, which is used in semiconductor manufacturing and microelectromechanical systems
Microelectromechanical systems
Microelectromechanical systems is the technology of very small mechanical devices driven by electricity; it merges at the nano-scale into nanoelectromechanical systems and nanotechnology...
for removing photoresist
Photoresist
A photoresist is a light-sensitive material used in several industrial processes, such as photolithography and photoengraving to form a patterned coating on a surface.-Tone:Photoresists are classified into two groups: positive resists and negative resists....
, or it may refer to the process below:
A test to deduce the amount of ash forming material present in a petroleum product so as to decide its use in certain applications. Ash-forming materials are considered to be undesirable impurities or contaminants.
The specimen is placed in a suitable vessel, evaporating dish
Evaporating dish
An evaporating dish is a piece of laboratory glassware used for the evaporation of solids and supernatant fluidsA fluid containing a saturated solution of a dissolved compound, overlying a forming precipitate of this compound., and sometimes to their melting point...
or crucible
Crucible
A crucible is a container used for metal, glass, and pigment production as well as a number of modern laboratory processes, which can withstand temperatures high enough to melt or otherwise alter its contents...
and ignited. It is allowed to burn until only ash and carbon remains. The carbonaceous residue is reduced to ash by heating in a muffle Furnace
Furnace
A furnace is a device used for heating. The name derives from Latin fornax, oven.In American English and Canadian English, the term furnace on its own is generally used to describe household heating systems based on a central furnace , and sometimes as a synonym for kiln, a device used in the...
at about 775oC, cooled and weighed.
Ashing is also performed prior to chemical analysis by inductively coupled plasma emission spectrometry.
See also
- Ash (analytical chemistry)Ash (analytical chemistry)In analytical chemistry, ashing is the process of mineralization for preconcentration of trace substances prior to chemical analysis. Ash is the name given to all non-aqueous residue that remains after a sample is burned, and consist mostly of metal oxides....
- Inductively coupled plasma emission spectrometry
- Atomic absorption spectroscopyAtomic absorption spectroscopyAtomic absorption spectroscopy is a spectroanalytical procedure for the qualitative and quantitative determination of chemical elements employing the absorption of optical radiation by free atoms in the gaseous state. In analytical chemistry the technique is used for determining the concentration...