| 摘要 |
In the manufacture of trench-gate power MOSFETs, trenched Schottky rectifiers and other devices including a Schottky barrier, a guard region (15s), trenched insulated electrode (11s) and the Schottky barrier (80) are self-aligned with respect to each other by providing spacers (52) to form a narrow window (52a) at a wider window (51a) in a mask pattern (51, 51s) that masks where the Schottky barrier (80) is to be formed. The trenched insulated electrode (11s) is formed by etching a trench (20) at the narrow window (52a) and by providing insulating material (17) and then electrode material (11s) in the trench. The guard region (15s) is provided by introducing dopant (61) via the wider window (51a). The mask pattern (51, 51s) masks the underlying body portion against this dopant introduction and is sufficiently wide (y8) to prevent the dopant (61) from extending laterally into the area where the Schottky barrier (80) is to be formed. Then at least the mask pattern (51, 51s) is removed before depositing a Schottky electrode (33).
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