Any semiconductor wafer fabrication process may be changed to monitor lateral
abruptness of doped layers as an additional step in the wafer fabrication process.
In one embodiment, a test structure including one or more doped regions is formed
in a production wafer (e.g. simultaneously with one or more transistors) and one
or more dimension(s) of the test structure are measured, and used as an estimate
of lateral abruptness in other doped regions in the wafer, e.g. in the simultaneously
formed transistors. Doped regions in test structures can be located at regularly
spaced intervals relative to one another, or alternatively may be located with
varying spacings between adjacent doped regions. Alternatively or in addition,
multiple test structures may be formed in a single wafer, with doped regions at
regular spatial intervals in each test structure, while different test structures
have different spatial intervals.