Measurement of Epitaxial Doping Density vs. Depth

The determination of doping density vs . depth from capacitance‐voltage measurements on diffused diodes in epitaxial material is derived for the general case. These calculations extend the useful range of the capacitance‐voltage technique and allow profiling of epitaxial doping in depth through the use of deep‐diffusion test diodes. Experimental comparison of the deep‐diffusion and shallow‐diffusion characterization techniques shows that the deep‐diffusion technique extends the depth capability of capacitance‐voltage measurements with accuracy comparable to the shallow‐junction measurements (5–15%).