Spectrophotometric Determination of Traces of Boron in High Purity Silicon

Abstract

A reddish brown complex is formed between boron and curcumin in concentrated sulphuric acid and glacial acetic acid mixture (1:1). the coloured complex is highly selective and stable for about 3 hours and has the maximum absorbance at 545 nm. the sensitivity of the method is extremely high and the detection limit is 3 parts per billion based on 0.004 absorbance value. the interference of some of the important cations and anions relevant to silicon were studied and it is found that 100 fold excess of most of these cations and anions do not interfere in the determination of boron. the method is successfully employed for the determination of boron in silicon used in semiconductor devices. the results have been verified by standard addition method.

Key Words:

• boron
• curcumin
• spectrophotometer