| 摘要 |
PURPOSE:To form a thin single crystal semiconductor region by providing a high concentration impurity layer of which bottom is partly thin within an isolation region in a dielectric separation type semiconductor IC. CONSTITUTION:A single crystal semiconductor region is composed of a single crystal layer 1 having comparatively low impurity concentration and a high impurity concentration layer of the same conductivity type as the layer 1, and it is insulatingly separated from a semiconductor substrate 4 because the bottom and side surfaces are surrounded by a dielectric isolation film 3. In this case, a high impurity concentration layer is formed in two kinds of thicknesses. The high impurity concentration layer 2a of them is a thin high concentration impurity layer formed in the vicinity of region where the depletion layer extends from the blocked PN junction of the bottom part of single crystal semiconductor region. The high concentration impurity layer 2b is thicker than the layer 2a. Thereby, the single crystal semiconductor region can be formed as shallow as a difference of the layers 2a and 2b, and a device can be manufactured as much easier. |
