← Back to Patent Explorer
US6507515B2 Expired / Lapsed US ⏱️ 0.0 years remaining

Semiconductor memory

Assignee: Fujitsu Semiconductor Ltd
•
Filing: 2002-01-17
•
Granted: 2003-01-14
•
Expires: 2022-01-17
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract First transistor rows are arranged, each including two transistors connected in series for selectively connecting any of memory cell rows to an input/output circuit. A switching transistor operates as a switch and a short transistor(s) each having a source and a drain shorted to each other function(s) as wiring. The first transistor rows are provided with a plurality of transistors in advance. Since there is no need to selectively form only such a transistor that is to be operated as a switch, there is no need to form ion-implanted regions for making a source and a drain per transistor. As a result, the spacing with which the transistors are arranged can be set without considering the layout rule of the diffusion layer regions. Since the transistors can be arranged closely, the layout area can be decreased and the chip size of the semiconductor memory can be reduced.

Inventors

  • 👤 Tsutomu Taniguchi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 06:41
CPC Classifications
H; H10; H10B; H10B69/00; G; G11; G11C; G11C16/00; G11C16/02; G11C16/06; G11C16/04; G11C16/0483; H10B41/00; H10B41/10; H10B41/30

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 89 words
A semiconductor memory comprising: a plurality of memory cell rows each having memory cells connected in series; an input/output circuit for inputting/outputting data to/from said memory cell rows; and a plurality of first transistor rows corresponding to each of said memory cell rows for selectively connecting any of said memory cell rows to said input/output circuit, said first transistor rows each including a switching transistor operating as a switch and a short transistor(s) each having a source and a drain shorted to each other, which are connected in series.
Claim 2
Dependent Claim 89 words
A semiconductor memory comprising: a plurality of memory cell rows each having memory cells connected in series; an input/output circuit for inputting/outputting data to/from said memory cell rows; and a plurality of first transistor rows corresponding to each of said memory cell rows for selectively connecting any of said memory cell rows to said input/output circuit, said first transistor rows each including a switching transistor operating as a switch and a short transistor(s) each having a source and a drain shorted to each other, which are connected in series.
Claim 3
Dependent Claim 39 words
The semiconductor memory according to claim 1 , comprising: local bit lines for connecting said memory cell rows to said first transistor rows, respectively; and a global bit line for connecting said first transistor rows to said input/output circuit.
Claim 4
Dependent Claim 53 words
The semiconductor memory according to claim 1 , comprising: a plurality of said memory cell rows corresponding to each of said first transistor rows; and selecting transistors in each of said memory cell rows for selectively connecting any of said memory cell rows to a corresponding transistor row of said first transistor rows.
Claim 5
Dependent Claim 30 words
The semiconductor memory according to claim 1 , wherein said source and said drain of said short transistor in each of said first transistor rows are shorted by metal wiring.
Claim 6
Dependent Claim 88 words
The semiconductor memory according to claim 1 , comprising: a voltage generator for supplying a predetermined voltage to the unselected memory cell row(s) among said memory cell rows; and a plurality of second transistor rows corresponding to each of said memory cell rows for selectively connecting said unselected memory cell row(s) to said voltage generator, said second transistor rows each including a switching transistor operating as a switch and a short transistor(s) each having a source and a drain shorted to each other, which are connected in series.
Claim 7
Dependent Claim 42 words
The semiconductor memory according to claim 5 , comprising: local bit lines for connecting said memory cell rows to said first and second transistor rows, respectively; and a common bit control line for connecting said second transistor rows to said voltage generator.
Claim 8
Dependent Claim 51 words
The semiconductor memory according to claim 6 , wherein said voltage generator supplies a first voltage and a second voltage to said local bit line(s) of said unselected memory cell row(s), respectively, when the selected memory cell row among said memory cell rows performs a read operation and a write operation.
Claim 9
Dependent Claim 26 words
The semiconductor memory according to claim 5 , wherein said input/output circuit and said voltage generator are arranged on both sides of said memory cell rows.
Claim 10
Dependent Claim 30 words
The semiconductor memory according to claim 1 , wherein said source and said drain of said short transistor in each of said second transistor rows are shorted by metal wiring.
Claim 11
Dependent Claim 34 words
The semiconductor memory according to claim 1 , wherein: said memory cells are nonvolatile memory cells each having a control gate and a floating gate; and said memory cell rows are of NAND type.

References Cited (Backward Citations)

US5293350A Cited
US5898616A Cited
US5909392A Cited
US6272046B1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2006-01-13 2006-07-15 2007-01-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2010-01-13 2010-07-15 2011-01-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2014-01-13 2014-07-15 2015-01-14 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag