| The optimization of reactor performance and the need for routine film evaluation make a quick determination of these borophosphosilicate glass (BPSG) dopant levels desirable. Though several methods have been utilized, the advantage of Fourier Transform Infrared (FT-IR) measurements is that boron, phosphorus and glass thickness can be simultaneously determined in a relatively fast (one minute), non-contact procedure.
The desirability of measuring BPSG films by FT-IR has been recognized for some time; however, the advent of both FT-IR systems designed to handle wafers and the incorporation of sophisticated computer methods of analysis have made the technique more applicable. Two methods of analysis, K-matrix and partial least squares (PLS), are available on Thermo's FT-IR metrology systems. |