Claims
- 1. A method of constructing a storage capacitor for a DRAM cell having:
- a word line connected to the gate electrode of a MOSFET,
- a bit line connected to a first diffusion of said MOSFET, a first electrode of said capacitor connected to a reference potential,
- a second electrode of said capacitor connected to a second diffusion of said MOSFET, separated from said first electrode by a dielectric layer and having a cross-section in the form of at least one shell enclosing a core, which traverses diagonally from one memory cell to another memory cell, comprising the steps of:
- defining the MOSFET area and isolation area outside said MOSFET area,
- patterning said gate electrode,
- depositing and patterning a first oxide to isolate the gate from the second electrode of said capacitor,
- depositing a first polysilicon to form the lower portion of said shell,
- depositing and patterning a second oxide to form said core,
- depositing and patterning a second polysilicon to form the upper portion of said shell,
- depositing a third oxide to form the dielectric of said capacitor,
- depositing and patterning a third polysilicon to form the first electrode of said capacitor,
- depositing an interlayer dielectric,
- opening a contact window in said interlayer dielectric over said first diffusion for said bit line, and
- depositing and patterning a conducting said bit line.
- 2. A method of constructing a storage capacitor as described in claim 1, wherein the step of defining the MOSFET and isolation areas is accomplished by a LOCOS process.
- 3. A method of consturcting a storage capacitor as described in claim 1, wherein said second oxide is doped.
- 4. A method of constructing a storage capacitor as described in claim 1, wherein said third oxide is deposited with an oxide-nitride-oxide process.
- 5. A method of constructing a storage capacitor as described in claim 1, wherein said core is filled with dielectric material.
- 6. A method of constructing a storage capacitor as described in claim 1, wherein said core is partially filled with dielectric material.
- 7. A method of consturcting a storage capacitor as described in claim 1, wherein said core is hollow.
- 8. A method of constructing a storage capacitor as described in claim 1, wherein said core is filled with the same material as, and connected to, said first electrode.
- 9. A method of constructing a storage capacitor as described in claim 1, wherein one said shell is stacked with another said shell.
- 10. A method of constructing a storage capacitor as described in claim 1, wherein an insulating spacer is placed around said shell.
Parent Case Info
This application is a division of application Ser. No. 08/568,245, filed Dec. 6, 1995, pending.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
5045899 |
Arimoto |
Sep 1991 |
|
Divisions (1)
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Number |
Date |
Country |
Parent |
568245 |
Dec 1995 |
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