| 摘要 |
PURPOSE:To prevent strain in a silicon oxide film in an element isolating region, by using an IVD method, by which nitrogen ion implantation and silicon evaporation are carried out at the same time, and depositing a silicon nitride film on a silicon substrate, in which a silicon oxide film as surface protecting film is patterned and formed in an element isolating region beforehand. CONSTITUTION:Thermal oxidation of a P-type silicon substrate 8 is performed, and a silicon oxide film 9 as a protecting film is formed. An opening part 10, which is to become an element isolating region, is formed by etching. Then, nitrogen ions having low accelerating energy are implanted by an IVD method, and silicon is evaporated with an electron beam at the same time. Thus a silicon nitride film 11 is deposited. At this time a silicon nitride film 12 is formed. The silicon nitride film 11 is etched back, and the film 11 is made to remain only at the opening part 10. The silicon oxide film 9 is removed by wet etching. An impurity ion implanted layer 13 at the element isolating region is formed on the upper surface of the substrate 8. High temperature oxidation is performed, and a silicon oxide film 14 is grown and formed on the layer 13. Then, the flat element isolating region C and an element forming region D, almost free of bird's beak, are formed.
|
