Claims
- 1. A memory cell of the type used in a semiconductor memory device for storing binary data of two bits, said memory cell comprising:
- a MOS transistor, said MOS transistor including a drain region, a source region, a channel region, and a gate electrode, said MOS transistor having a plurality of threshold voltage portions, wherein the threshold voltage of said MOS transistor is varied according to the data to be stored in said memory cell, and one of said threshold voltage portions extends with a predetermined length from one side of said channel region with respect to the length direction of said channel region.
- 2. The memory cell according to claim 1, wherein said MOS transistor has at least two threshold voltage portions, a threshold voltage of one of said threshold voltage portions is higher than a threshold voltage of other of said threshold voltage portions.
- 3. The memory cell according to claim 2, wherein said one of said threshold voltage portions has such a predetermined length as to be in contact with said drain region and out of contact with said source region.
- 4. The memory cell according to claim 2, wherein said one of said threshold voltage portions has such a predetermined length as to be in contact with said source region and out of contact with said drain region.
- 5. The memory cell according to claim 2, wherein one of said threshold voltage portions has such a predetermined length as to be in contact with said drain region and out of contact with said source region, and another of said threshold voltage poritons has such a predetermined length as to be in contact with said source region and out of contact with said drain region.
Priority Claims (1)
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Date |
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6-011029 |
Feb 1994 |
JPX |
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Parent Case Info
This is a continuation of application Ser. No. 08/891,959 filed Jul. 14, 1997, now U.S. Pat. No. 5,793,690, which application is hereby incorporated by reference in its entirety. Application Ser. No. 08/891,959 was a division of application Ser. No. 08/382,491 filed Feb. 1, 1995, now U.S. Pat. No. 5,650,656.
US Referenced Citations (16)
Foreign Referenced Citations (5)
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448141 |
Sep 1991 |
EPX |
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JPX |
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JPX |
2084828 |
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GBX |
8001119 |
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WOX |
Non-Patent Literature Citations (1)
Entry |
"Mid-Level Current Generator Circuit", IBM Technical Disclosure Bulletin, vol. 33, No. 1B, Jun. 1990, pp. 386-388. |
Divisions (1)
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Number |
Date |
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Parent |
382491 |
Feb 1995 |
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Continuations (1)
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Parent |
891959 |
Jul 1997 |
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