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US5210429A Expired / Lapsed US ⏱️ 0.0 years remaining

Static RAM cell with conductive straps formed integrally with thin film transistor gates

Assignee: Sharp Corp
•
Filing: 1992-07-22
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Granted: 1993-05-11
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Expires: 2012-07-22
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Abstract

Abstract A static RAM cell including first and second bulk transistors having gate electrodes extended over an element isolation region and forming a flip-flop, third and fourth bulk transistors having source and drain regions and formed adjacently to the element isolation region, a first conductive strap layer for self-aligning the gate electrode of the first bulk transistor with the source or drain region of the third bulk transistor, and a second conductive strap layer for self-aligning the gate electrode of the second bulk transistor with the source or drain region of the fourth bulk transistor.

Inventors

  • 👤 Alberto O. Adan

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 03:08
CPC Classifications
H; H10; H10B; H10B10/00; H10B10/12; H10B10/125; H10B10/15; Y; Y10; Y10S; Y10S257/00; Y10S257/903

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 146 words
A static RAM cell comprising a flip-flop circuit having two inverters connected to each other, and two access transistors for connecting nodes of said flip-flop circuit to bit lines; wherein said inverters are formed on a semiconductor substrate and comprise first and second bulk transistors respectively having gate electrodes extending to a device isolating region, and thin film transistors having gate electrodes, said thin film transistors being formed on said first and second bulk transistors; wherein said access transistors comprise third and fourth bulk transistors having source/drain regions formed adjacent said device isolating region; and wherein said gate electrodes of said first and second bulk transistors are connected to said source/drain regions of said third and fourth bulk transistor, respectively through first and second conductive strap layers, said first and second conductive strap layers being formed integrally with the gate electrodes of said thin film transistors.
Claim 2
Dependent Claim 146 words
A static RAM cell comprising a flip-flop circuit having two inverters connected to each other, and two access transistors for connecting nodes of said flip-flop circuit to bit lines; wherein said inverters are formed on a semiconductor substrate and comprise first and second bulk transistors respectively having gate electrodes extending to a device isolating region, and thin film transistors having gate electrodes, said thin film transistors being formed on said first and second bulk transistors; wherein said access transistors comprise third and fourth bulk transistors having source/drain regions formed adjacent said device isolating region; and wherein said gate electrodes of said first and second bulk transistors are connected to said source/drain regions of said third and fourth bulk transistor, respectively through first and second conductive strap layers, said first and second conductive strap layers being formed integrally with the gate electrodes of said thin film transistors.
Claim 3
Dependent Claim 29 words
A static RAM cell according to claim 1, wherein the first and second conductive strap layers formed by polysilicon or polycide which is obtained by laminating silicide on polysilicon.
Claim 4
Dependent Claim 19 words
A static RAM cell according to claim 1, wherein the respective bulk transistors have gate electrodes formed by polysilicon.
Claim 5
Dependent Claim 37 words
A static RAM cell as in claim 1 wherein said thin film transistors are of a double insulated gate construction and each of said conductive strap layers forms an electrode of one of said thin film transistors.

References Cited (Backward Citations)

US4453175A Cited
US4792841A Cited
US4774203A Cited
US4984200A Cited
EP0365690A1 Cited
EP0420646A2 Cited
US5057898A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-05-10 1996-11-09 1997-05-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-05-10 2000-11-09 2001-05-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-05-10 2004-11-09 2005-05-11 $7700.00 Window Closed / Lapsed

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