Integrated Circuit Structure and Method with Solid Phase Diffusion

A device comprising:

• a semiconductor substrate having a first surface and an opposing second surface;
• a first fin feature and a second fin feature formed on the first surface of the semiconductor substrate;
• a first anti-punch through (APT) feature formed on the first fin feature;
• and
• a second APT feature formed on the second fin feature, wherein the second APT feature is closer to the second surface of the semiconductor substrate than the first APT feature.

A method comprising:

• forming a fin feature on a semiconductor substrate;
• forming a material layer containing a dopant over the fin feature;
• transferring the dopant from the material layer to the fin feature, thereby forming an anti-punch-through (APT) feature on the fin feature;
• removing the material layer;
• and
• forming a semiconductor material layer on the APT feature.