Method and apparatus for real-time dynamic chemical analysis

A method for real-time dynamic analysis of chemical etching, comprising the steps of:

• passing electromagnetic radiation from an electromagnetic radiation source through an aqueous etchant solution comprising at least one inorganic etchant species, at at least two points in time, wherein said aqueous etchant solution is operative to etch an inorganic solid;
• performing ex situ non-contact scanning detection over a predetermined spectral range of said electromagnetic radiation passed through said aqueous etchant solution, by means of a detector over said at least at two points in time so as to detect at least one change in at least one optical property of said aqueous etchant solution over said predetermined spectral range;
• and
• comparing said at least one change in said at least one optical property over said predetermined spectral range at said at least two points in time by means of an algorithm in a processor so as to provide a rate of etching of said inorganic solid, wherein said algorithm includes a calibration model developed by using a method comprising the steps of:
• obtaining a plurality of calibration samples of the aqueous etchant solution, wherein each calibration sample has a known etch rate, and irradiating said plurality of calibration samples of the aqueous etchant solution with electromagnetic radiation and recording their respective at least one optical property over said predetermined spectral range;
• determining variations of their respective at least one optical property over said predetermined spectral range so as to correlate at least one optical property of said plurality of calibration samples with said known etch rate;
• and
• developing a calibration model based on the results of said step of determining.