Claims
- 1. A memory array comprising:a plurality of floating gate transistors connected in series, each floating gate transistor having formed, in a well of a substrate, a source and a drain region and a channel region separating said source and drain regions, a dopant concentration region displaced about a target region, said target region situated below said channel region, said dopant concentration region extending into said channel region such that said channel region has a non-uniform concentration of dopant; wherein said well has a first conductivity type, said source and said drain regions have a second conductivity type, and said dopant concentration region has said second conductivity type.
- 2. The memory array of claim 1 wherein said dopant concentration region is formed by a tilted ion implantation utilizing as a mask, at least a part of a gate structure of each floating gate transistor.
- 3. A transistor comprising:in a well structure of a substrate, a source and a drain region and a channel region separating said source and said regions, a dopant concentration region displaced about a target region, said target region situated below said channel region, said dopant concentration region extending into said channel region such that said channel region has a non-uniform concentration of dopant; wherein said well structure has a first conductivity type, said source and said drain regions have a second conductivity type, and said dopant concentration region has said second conductivity type.
- 4. The transistor of claim 3 wherein said dopant concentration region is provided by a tilted ion implantation utilizing as a mask, at least part of a gate structure of said transistor.
- 5. The transistor of claim 3, wherein the transistor is an NMOS transistor.
- 6. The NMOS transistor of claim 5, wherein the NMOS transistor is a floating gate transistor.
Parent Case Info
This application claims the benefit of Provisional application Ser. No. 60/165,882, filed Nov. 16, 1999.
US Referenced Citations (28)
Non-Patent Literature Citations (1)
Entry |
Yang, Edward S., “Microelectronic Devices”, McGraw-Hill Book Company, 1998, pp. 305-311. |
Provisional Applications (1)
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Number |
Date |
Country |
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60/165882 |
Nov 1999 |
US |