| 摘要 |
<p>An isolation method for separating active regions in a semiconductor substrate by combining field oxide formation with trench isolation is disclosed. Deep trenches are etched in a silicon substrate. An oxide layer is deposited over the entire substrate such that the oxide layer also fills the trenches that have been etched. Next, a layer of polysilicon is deposited over the wafer and etched back to form polysilicon spacers. These polysilicon spacers are used to align a photoresist mask that is used to etch the oxide overlying the active regions of the substrate, thereby resulting in fully planarized isolation regions with fully walled active regions.</p> |
