| 摘要 |
A method of forming a shallow trench isolation structure such that the shoulders of the wall formations on either side of the trench are rounded, whilst the walls and floor of the trench as well as the top surface of the formations on either side of the trench remain flat. This is achieved by anchoring the walls and floors with a partial gap fill, which may be achieved either by fully filling the gap and then reducing the level to below that of the formations on either side a the trench by polishing and etching steps, or by not completely filling the trench in the first place. The tops of the formations on either side of the trench meanwhile are protected by an oxide layer, which is pared back from the edge of the trench, for example by means of an isotropic etching process. |
