Importance

Loading Importance Indicators...

Abstract

Plating cups 2 each hold therein respective semiconductor substrates to be plated. The temperatures of the plating solution in the plating cups are controlled at optimum levels by controlling the operations of heaters 13 and 16, based on the temperature of the plating cups as measured by thermometers 5 mounted on the plating cups 2. Metal ion concentration in the solution and the pH level and specific gravity of the solution are measured by an atomic absorption spectrometer 17, a pH gauge 18, and a gravimeter 19, respectively, for determining necessary amount of replenishing metal ions and solution from a solution level regulator 21, thereby maintaining the relevant parameters of the solution within a permissible range.

Loading the Abstract Image...

First Claim