| 摘要 |
PROBLEM TO BE SOLVED: To suppress a variation of gaps between the tip of the projection provided, directly underneath a movable portion and the movable portion in the direction of thickness in a semiconductor dynamic quantity sensor wherein a movable portion is partitioned from a semiconductor layer by a groove reaching an insulation layer and the insulation layer, directly underneath the movable portion is removed through the groove.SOLUTION: A substrate made of single-crystal silicon is prepared, wherein a semiconductor layer that is made of P conductivity-type silicon having higher impurity concentration than a semiconductor substrate and is arranged on the surface of the semiconductor substrate, with a surface having (100) plane with an insulation layer in between. The semiconductor layer is etched anisotropically to form a groove reaching the insulation layer, so as to partition a movable portion. The insulation layer is etched through the groove, making the groove to reach the semiconductor substrate, and the width of the insulation layer, directly underneath the movable portion in the horizontal direction is made smaller than that of the movable portion. The groove is subject to alkali-etching through the groove, and a projection the tip of which is in contact with the insulation layer is formed on the surface of the semiconductor substrate directly underneath the movable portion. The insulation layer located directly underneath the movable portion is removed. |
