Abstract: A method and apparatus for cleaning a wafer with a metal exposed through an insulator, through the use of a wet cleaning tank in concert with a feedback system on the potential difference between two leads of the wet cleaning tank. The cleaning tank has a bath in which the wafer and the two leads are immersed. The potential difference between the two leads is regulated when the feedback system detects a change in the potential across the two leads.

Abstract: A method for preparing diphenol compounds, which method includes the steps of coupling a hydroxyphenyl carboxylic acid with a L-tyrosine ester in a water-miscible organic reaction solvent containing a carbodiimide capable of forming a water-soluble urea by-product, thereby forming a diphenol reaction product; and combining the reaction mixture with an amount of water effective to precipitate the diphenol as a water-immiscible organic phase, so that a water-immiscible organic phase is formed containing the diphenol reaction product. New diphenol monomers and polymers polymerized therefrom are also disclosed.

Abstract: A method for preparing diphenol compounds, which method includes the steps of coupling a hydroxyphenyl carboxylic acid with a L-tyrosine ester in a water-miscible organic reaction solvent containing a carbodiimide capable of forming a water-solvent urea by-product, thereby forming a diphenol reaction product; and combining the reaction mixture with an amount of water effective to precipitate the diphenol as a water-immiscible organic phase, so that a water-immiscible organic phase is formed containing the diphenol reaction product. New diphenol monomers and polymers polymerized therefrom are also disclosed.