Etching cleaning

Complexed metals Electroless plating Etching Cleaning... 

Applications of CF4, C2F( and NF3 to plasma etching/cleaning in semiconductor industries... 

Chemical etching. Cleaned parts are immersed for 10 to 30 s into a fluoronitric mixture (25 to 35 wt.% HNO3 with 15 to 30 cm HF per liter) followed by a thorough rinse with deionized water. 

Bilouk, S., Broussous, L., Nogueira, R.P., et al., 2009. Electrochemical behavior of copper and cobalt in post-etch cleaning solutions. Microelectron. Eng. 86, 2038—2044. 

A problem common to etching printed boards is not having the entire area etch clean at the same time. This occurs when etch action is more rapid at the edges of printed areas than in a broad expanse of copper. If very fine patterns and lines are required, the result can be loss of the pattern due to undercutting, especially when the board is left in the etcher until all the field copper has etched away. Modern etchers with reduced pooling of etchant have reduced this problem. 

Standard image-transfer methods are suitable. Pre-etch cleaning shonld inclnde a dip in dilute nitric add. Mixtures of nitric and sulfuric adds are effective etchants. With silver on brass or copper substrates, a mixture of 1 part nitric add (70 percent) and 19 parts snlfnric add (96 percent) will dissolve the silver withont attacking the snbstrate. The solutions shonld be changed frequently to prevent water absorption and the formation of immersion silver on the copper. 

The reactive etching/cleaning processes produce volatile species, which may be deposited in other parts of the system where there are different plasma conditions. This may have a detrimental effect on the gas handling/pumping system and can be a source of particulates in... 

Chemical etching (cleaning) The removal of material by chemical reaction with a fluid (wet chemical etching) or vapor (vapor etching) to produce a soluble or volatile reaction product. The etch rate is affected by the density, porosity, and composition of the film. 

Etching, cleaning by Removing surface material (often substrate material) by chemical etching. Removal of the surface material also removes the contamination. See also Gross cleaning. 

Vapor phase etching (cleaning) Chemical etching using a vapor instead of a fluid. 

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