Claims
- 1. A method of fabricating a metal-oxide semiconductor in a semiconductor substrate comprising:providing a semiconductor substrate having an active region isolated by a shallow isolation trench formed thereon; filling the shallow isolation trench with a doped silicon oxide, wherein the doped silicon oxide layer comprises dopants selected from the group consisting of germanium, nitrogen, and refractory metal; forming a trench in the active region of the semiconductor substrate; forming a spacer on a sidewall of the trench; forming a gate oxide layer on a bottom surface of the trench; filling the trench with a conductive layer to form a gate; and forming source/drain region in the substrate between the shallow trench isolation and the spacer of the gate.
- 2. The method according to claim 1, wherein the active region comprises a well region formed prior to the formation of the shallow trench isolation.
- 3. The method according to claim 2, wherein the doped silicon oxide layer filling the shallow trench isolation comprises dopant selected from a group consisting of germanium, nitrogen, titanium, and other refractory metal.
- 4. The method according to claim 2, wherein the conductive layer comprises a polysilicon layer.
- 5. The method according to claim 2, wherein the source/drain regions are formed using the gate, the spacer and the shallow trench isolation as a mask to perform an ion implantation step.
- 6. The method according to claim 2, comprising further a step of forming a salicide layer to cover the source/drain regions and the gate.
CROSS-REFERENCE TO RELATED APPLICATION
This is a application of prior application Ser. No. 09/360,102 filed on Jul. 23, 2000, abandoned which is a CIP of Ser. No. 08/915,661, Aug. 21, 1997 abandoned and a CIP of Ser. No. 09/304,143, May 3, 1999, U.S. Pat. No. 6,306,722 the disclosure of which is incorporated herein by reference.
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Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
08/915661 |
Aug 1997 |
US |
Child |
09/360102 |
|
US |
Parent |
09/304143 |
May 1999 |
US |
Child |
08/915661 |
|
US |