Goodbye black & white, SCM easily determines P/N type with colors

A P/N well is determined, in most cases, by staining the chip before measuring its width, depth, and epitaxial layer thickness with a scanning electron microscope (SEM). There is one drawback: Rather than solid data or color for P/N well identification, the B&W image by SEM requires the input of personal judgment and educated guesses. This is where the color features of SCM can do P/N well determination better.

The (AFM) atomic force microscope-mounted SCM detection module directly captures dC/dV signals by measuring with an AC conductive probe on samples after the cover adhesive is removed. This gives the P/N distribution for P/N well determination with changing color bars.

For the best P/N identification, it is recommended to obtain its width and depth based on a clear SEM image and then identify the position of the chip pattern with electrical color block analysis by SCM.

See below for an example of SEM and SCM integrated work. The SEM graphics to the left gives width and depth, the B&W electronic image can determine P/N wells together with the SCM picture to the right. That is: the positive electric (in purple) is a P well while the negative electric (in red) is an N well.