PROCESS OF MAKING SEMICONDUCTOR DEVICE HAVING REGIONS OF INSULATING MATERIAL FORMED IN SEMICONDUCTOR SUBSTRATE

摘要

PURPOSE: A Process of making a semiconductor device having regions of insulating material formed in a semiconductor substrate is provided to form a structure that has islands of insulating silicon dioxide formed in the silicon substrate and below the substrate surface. CONSTITUTION: A height of a silicon dioxide region on a substrate surface defines the coupled thickness of the island of silicon dioxide and a silicon formed thereon. The silicon dioxide region which is formed allows formation of a mask on a silicon substrate. The mask demarcates a region on the surface of silicon substrate where the island of silicon dioxide is formed. The silicon dioxide island is formed at an appropriate place with a mask which is removed later. Single crystal silicon is formed epitaxially within a structure. Then an amorphous silicon is deposited and re-crystallized, forming a structure where a silicon substrate and the island of insulating silicon dioxide formed under the surface of substrate are provided. Chemical mechanical polishing is one example of a suitable expedient for accomplishing this objective. The resulting structure has silicon dioxide insulating regions(15) that separate active regions(17) in the substrate(10). At least, one active region(17) has silicon dioxide islands(35) formed beneath the single crystalline surface.