Claims
- 1. A method of forming a semiconductor device, comprising the steps of:
- (a) providing a silicon substrate having a trench filled with polysilicon and having insulating sidewalls and bottom;
- (b) forming a layer of polysilicon extending over said insulating sidewalls in said trench and contacting said substrate, and burying said insulating sidewalls in said trench with polysilicon; and
- (c) oxidizing said polysilicon at the upper surface of said trench and a portion of the upper surface of said substrate exterior of said trench and extending to said trench to form a continuous field oxide over said trench which extends over said substrate.
- 2. A method as set forth in claim 1, wherein said polysilicon formed in step (b) extends over said substrate exterior to said trench.
- 3. A method as set forth in claim 2, wherein step (b) includes removing a portion of said insulating sidewall in the region thereof extending from the upper edge of said trench toward the interior thereof and filling the region of removed sidewall with said polysilicon.
- 4. A method as set forth in claim 3 wherein, in step (a), an oxide layer is provided over said substrate, said step of removing said portions of said sidewall includes removal of a portion of said oxide layer and said step of filling said region of removed sidewall also includes filling said region of removed oxide layer.
- 5. A method as set forth in claim 4 wherein a silicon nitride layer is provided over said oxide layer in step (a).
- 6. A method as set forth in claim 1, wherein step (b) includes removing a portion of said insulating sidewall in the region thereof extending from the upper edge of said trench toward the interior and filling the region of removed sidewall with said polysilicon.
- 7. A method as set forth in claim 6 wherein, in step (a), an oxide layer is provided over said substrate, said step of removing said portions of said sidewall includes removal of a portion of said oxide layer and said step of filling said region of removed sidewall also include filling said region of removed oxide layer.
- 8. A method as set forth in claim 7 wherein a silicon nitride layer is provided over said oxide layer in step (a).
Parent Case Info
This is a continuation of application Ser. No. 07/314,326, filed 02/22/89, now abandoned.
US Referenced Citations (8)
Foreign Referenced Citations (3)
Number |
Date |
Country |
0172772 |
Feb 1986 |
EPX |
0137647 |
Oct 1981 |
JPX |
0032646 |
Feb 1989 |
JPX |
Continuations (1)
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Number |
Date |
Country |
Parent |
314326 |
Feb 1989 |
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