| 摘要 |
<p>A method for forming uniformly thick, thermally grown, silicon dioxide on a silicon body independent of crystallographic axis. A trench is formed in the silicon body having sidewalls disposed in different crystallographic planes, one of which being the (100) plane and another one being the (110) plane. A uniform layer of silicon nitride is formed on the sidewalls which is then oxidised with sidewalls in the (110) plane being oxidized at a higher rate than sidewalls in the (100) plane producing silicon dioxide on the silicon nitride having thickness over the (110) plane greater than over the (100) plane. The silicon dioxide is etched to selectively remove silicon dioxide while leaving un-etched silicon nitride to thereby remove portions of the silicon dioxide over the (100) plane and to expose underlying portions of the silicon nitride while leaving portions of the silicon dioxide over the (110) plane on underlying portions of the silicon nitride. Exposed portions of the silicon nitride are selectively removed to expose underlying portions of the sidewalls disposed in the (100) plane while leaving un-etched portions of the silicon nitride disposed on sidewalls disposed in the (110) plane. The structure is then oxidised to produce the uniform silicon dioxide layer on the sidewalls.</p> |
