| 摘要 |
PURPOSE:To improve the quality of a device by boring a recess in the case of forming an element separating region on the surface of a substrate covering the substrate and the side wall and bottom of the recess with an insulating film, making a poly-crystal Si layer adhere to only the above side wall and filling the poly-crystal Si into the recess, and thereafter converting the surface of the Si layer into an SiO2 film, thereby to stabilize the Si filling. CONSTITUTION:When an element separating region is formed on the surface of a substrate 1, firstly a recess 1a is bored and a non-crystallaine insulating film 1b made from Si3N4 or the like is made to adhere to the whole surface. Next, a poly-crystal Si film 5 is built up on the insulating film 16 and the film 5 is subjected to directional reactive sputter-etching, thereby to make the film 5 leave only on the insulating film 16 existing on the side wall of the recess 1a and remove the film 5 on the other portion. After that, a poly-crystal Si body 4 is filled in the recess 1a and subjected to heat-treatment, thereby to convert only the surface of the body 4 into an SiO2 film 6. In this way, portions except the filled portion are surrounded by the film 1b to stably secure the Si filling. |
