| 摘要 |
<p>PURPOSE: To minimize a bird's beak formed from an element separation area to an element formation area, by preventing flank diffusion of an oxide film by a 2nd silicon nitride film formed in a field area when a field oxide film is grown. CONSTITUTION: After a pad oxide film 12 is grown on a semiconductor substrate 11, a polysilicon film 13 and a 1st silicon nitride film 14 are formed. To limit an active area, the 1st silicon nitride film 14 in patterned. Then, a 2nd silicon nitride film 15 and an oxide film 16 which are formed over the entire surface are etched anisotropically to form an oxide film spacer 16a and a nitride film spacer 15a. Those are used as a mask for the ion injection of impurities, forming a channel stop area 17. Then, the oxide film spacer 16a is removed and a field oxide film 18 is grown. At this time, the L-shaped nitride film spacer 15a prevents the flank diffusion by the oxide film at the time of the field oxide film growth, so the spread of the bird's beak is suppressed.</p> |
