Semiconductor device and method of manufacturing thereof

• US 20070138518A1
• Filed: 02/16/2007
• Published: 06/21/2007
• Est. Priority Date: 07/11/2001
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Technology Corporation (Renesas Electronics Corporation)
• Inventors: Inoue, Masao
• Granted Patent: US 7,683,455 B2
• Time in Patent Office: Days
• US Class Current: 257/288
• CPC Class Codes: H01L 21/28211 in a gaseous ambient using an oxygen or a water vapour, e.g. RTO, possibly through a layer H01L21/28194 and H01L21/28202 take precedence
• CPC Class Codes: H01L 21/76224 using trench refilling with dielectric materials trench filling with polycristalline silicon H01L21/763; together with vertical isolation, e.g. trench refilling in a SOI substrate H01L21/76264
• CPC Class Codes: H01L 21/823481 isolation region manufacturing related aspects, e.g. to avoid interaction of isolation region with adjacent structure
• CPC Class Codes: H01L 29/40114 the electrodes comprising a conductor-insulator-conductor-insulator-semiconductor structure
• CPC Class Codes: H01L 29/7881 Programmable transistors with only two possible levels of programmation H01L29/7888 takes precedence

Abstract

An active region on a semiconductor substrate is electrically isolated by trench isolation. A structure of the trench isolation is constituted of: a trench; a silicon oxide film formed on the inner wall of trench; an oxidation preventive film formed between silicon oxide film and semiconductor substrate; and a filling oxide film filling trench. Gate oxide film is formed by oxidation having a high capability by which radicals of at least one kind of hydrogen radicals and oxygen radicals are generated. Thereby, gate oxide film is formed so as to have a almost uniform thickness such that a thickness of a region directly above oxidation preventive film and a thickness of a region directly below gate electrode are almost the same is each other. According to the above procedure, there are obtained a semiconductor device having good transistor characteristics and a fabrication process therefor.

Claims

1-5. -5. (canceled)

6. A semiconductor device comprising:

a semiconductor substrate having a trench at a main surface thereof;

an oxidation preventive film formed along an inner wall of said trench;

a filling layer filling said trench;

a gate oxide film formed on said main surface of said semiconductor substrate and said oxidation preventive film; and

a gate electrode formed on said gate oxide film,

wherein said gate oxide film has almost the same thickness in a region directly above said oxidation preventive film and a region directly below said gate electrode.

7. The semiconductor device according to claim 6, wherein said gate electrode has a floating gate electrode and a control gate, insulated from each other.

8. The semiconductor device according to claim 6, wherein said oxidation preventive film is made from at least one of a silicon nitride film and a silicon oxynitride film.