| 摘要 |
An isolation trench is formed from a first isolation trench in an integrated circuit substrate between active regions in the integrated circuit substrate. An insulating layer is formed in the first isolation trench, wherein the insulating layer includes a portion that protrudes from the first isolation trench. A second isolation trench is formed on the first isolation trench and self-aligned to the active regions in the integrated circuit substrate, wherein the second isolation trench includes the protruding portion of the insulating layer. By forming the isolation trench in two steps, the isolation trench may be formed to the appropriate depth without developing a seam in the insulating layer. In particular, the first isolation trench is formed to a depth and filled with the insulating layer which protrudes from the trench. The second isolation trench is built up around the protruding insulating layer to provide the total depth for adequate isolation of the active areas. The isolation trench may thereby provide improved reliability of the integrated circuit.
|
