| 摘要 |
<p>In a process for forming dielectric isolation regions in a semiconductor substrate (10), trenches (13) are formed in the substrate (10), whereafter there are formed in turn a stress relief oxide layer (16), an etch-stop polysilicon layer (17), a nitride layer (18) and an isolation oxide layer (19) formed of doped silicon dioxide. The structure is heated to reflow the isolation oxide layer (19) thereby collapsing any voids (21) therein and planarizing the surface. The structure is then etched back to the polysilicon layer (17) outside the trenches (13) and the structure is heated to remove dopant from a surface adjacent region of the isolation oxide layer (19) remaining in the trenches (13).</p> |
