| 摘要 |
A trench-gate semiconductor device, for example a MOSFET or IGBT, of compact geometry is manufactured with self-aligned masking techniques in a simple process with good reproducibility. The source region (13) of the device is formed by introducing dopant (63) into an area of the body region (15) via a mask window (51a), diffusing the dopant to form a surface region (13b) that extends laterally below the mask (51) at a distance (d) beyond the masking edge (51b) of the window (51a), and then etching the body (10) at the window (51a) to form a trench (20) for the trench-gate (11) with a lateral extent (y) that is determined by the etching of the body (10) at the masking edge (51b) of the window (51a). A portion of the surface region (13b) is left to provide the source region (13) adjacent to the trench (20). The invention permits the etch edge definition for the trench (2) to be better controlled by using the masking edge (51b) of a well-defined mask (51), as compared with the less well defined edges that tend to result from the use of a side-wall extension in prior-art processes.
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