| 摘要 |
<p>PURPOSE: To suppress the bird's beak of isolation oxide from extending and crystal defect from being generated on the major surface of a silicon substrate by depositing an oxynitride having composition varying in the direction of thickness. CONSTITUTION: An oxynitride 2, having compositional ratio of oxygen and nitride varying in the direction of thickness, is deposited on the major surface of a silicon substrate 1 and a silicon nitride 3 is deposited thereon. Composition of the oxynitride 2 is conditioned to be close to silicon oxide at the part close to the silicon substrate 1 and becomes close to silicon nitride toward the silicon nitride 3. The silicon nitride 3 and the oxynitride 2 are then patterned, respectively, into predetermined shapes. Finally, the major surface of the silicon substrate 1 is thermally oxidized using the silicon nitride 3 and the oxynitride 2 as a mask.</p> |
