| 摘要 |
PURPOSE:To enable effective positioning by forming positioning marks in two directions in manufacturing processes different to each other, and then using them as a pair of positioning marks after that. CONSTITUTION:In a MOS type transistor, positioning margins for a contact hole 102 are in the X direction 105 and in the Y direction 106. Since the one which determines the margin in the X direction is a gate electrode position, the superposition mark in the X direction 204 is made of gate electrode material. On the other hand, the margin in the Y direction 106 is already determined with an active region 101, and it has nothing to do with a gate electrode 103, so the superposition mark in the Y direction 106 is so formed that a contact hole formation process 203 may be conformed to the boundary formed by an active region 201. Since the marks are formed each independently in the X and Y directions with materials which attain the real limits to implement the positioning this way, strict superposition margin can be secured, which is effective for cost reduction and yield rate improvement. |
