Abstract
The behavior of nickel adsorption during caustic etching of boron-doped silicon wafer is investigated. Caustic solutions considered for investigation are sodium hydroxide (NaOH) and potassium hydroxide (KOH). In addition to the amount of nickel present in the caustic solution, the degree of nickel contamination of the wafer is also affected by the dopant concentration, temperature and nature of the caustic solutions used. Control of nickel contamination by various additives to the caustic solution is found to be effective and comparable to each other. The possible mechanism of nickel adsorption is explained by considering metal stability in specific caustic solution and the electro-chemical potential of the silicon surface in presence of etching solution.