1. A semiconductor memory device comprising:
a semiconductor substrate;
a cell array layer which is formed above the semiconductor substrate and includes a first wiring and a second wiring, which cross each other, and a memory cell connected to the first and second wirings at an intersection thereof;
a third wiring formed on a first wiring layer below the cell array layer;
a fourth wiring formed on a second wiring layer above the cell array layer; and
a contact extending in a stacking direction for connecting the third wiring and the fourth wiring, wherein
the semiconductor memory device further comprises
a redundant wiring layer being formed between the first wiring layer and the second wiring layer,
the redundant wiring layer being formed with a redundant wiring having a portion extending in the same direction as at least one of the third wiring and the fourth wiring, and
the third wiring and the redundant wiring, and the fourth wiring and the redundant wiring being connected by a plurality of contacts arranged along the portion extending in the same direction as the third wiring or the fourth wiring.
2. The semiconductor memory device according to claim 1, wherein
the redundant wiring layer is formed on the same wiring layer as that of at least one of the first wiring and the second wiring of the memory cell layer.
3. The semiconductor memory device according to claim 1, wherein
a plurality of redundant wiring layers are provided, and
the redundant wirings are formed on the different redundant wiring layers and connected to each other by the plurality of contacts.
4. The semiconductor memory device according to claim 1, wherein
the third wiring is orthogonal to the fourth wiring, and
the redundant wiring is formed into an L-shape having a portion extending in the same direction as the third wiring and a portion extending in the same direction as the fourth wiring.
5. The semiconductor memory device according to claim 4, wherein
the L-shaped redundant wiring is shifted in the same direction as the third wiring and in the same direction as the fourth wiring with respect to the other L-shaped redundant wiring adjacent to the redundant wiring.
6. The semiconductor memory device according to claim 3, wherein
the third wiring is orthogonal to the fourth wiring,
a part of the redundant wiring is formed into an L-shape having a portion extending in the same direction as the third wiring and a portion extending in the same direction as the fourth wiring, and
a part of the other redundant wiring is formed into a reed shape extending in the same direction as the third wiring or the fourth wiring.
7. The semiconductor memory device according to claim 1, wherein
the memory cell includes a variable resistor.
8. The semiconductor memory device according to claim 7, wherein
the memory cell includes a diode connected to the variable resistor in series.
9. A semiconductor memory device comprising:
a semiconductor substrate;
a cell array layer which is formed above the semiconductor substrate and includes a first wiring and a second wiring, which cross each other, and a memory cell connected to the first and second wirings at an intersection thereof;
a third wiring formed on a first wiring layer below the cell array layer;
a fourth wiring formed on a second wiring layer above the cell array layer; and
a contact extending in a stacking direction for connecting the third wiring and the fourth wiring, wherein
the semiconductor memory device further comprises
a redundant wiring layer being formed between the first wiring layer and the second wiring layer, and
the third wiring and the redundant wiring, and the fourth wiring and the redundant wiring being connected by a contact having a width, in the direction in which the third wiring or the fourth wiring extends, greater than a width of the third wiring or the fourth wiring.
10. The semiconductor memory device according to claim 9, wherein
the redundant wiring layer is formed on the same wiring layer as that of at least one of the first wiring and the second wiring of the memory cell layer.
11. The semiconductor memory device according to claim 9, wherein
the third wiring and the fourth wiring are respectively extend in the directions which are at right angles to each other, and
a width and a length of the redundant wiring are set to be greater than the widths of the third wiring and the fourth wiring.
12. The semiconductor memory device according to claim 9, wherein
the redundant wiring is formed to have a rectangular shape.
13. A semiconductor memory device comprising:
a semiconductor substrate;
a plurality of memory blocks formed above the semiconductor substrate in a matrix and each of which includes stacked cell array layers, the cell array layer including a first wiring and a second wiring, which cross each other, and a memory cell connected to the first and second wirings at an intersection thereof;
a third wiring formed on a first wiring layer below the cell array layer;
a fourth wiring formed on a second wiring layer above the cell array layer; and
a contact extending in a stacking direction for connecting the third wiring and the fourth wiring, wherein
the semiconductor memory device further comprises
a redundant wiring layer being formed between the first wiring layer and the second wiring layer,
the redundant wiring being formed on the redundant wiring layer and having a portion extending in the same direction as at least one of the third wiring and the fourth wiring, and
the third wiring and the redundant wiring, and the fourth wiring and the redundant wiring being connected by a plurality of contacts arranged along the portion extending in the same direction as the third wiring or the fourth wiring.
14. The semiconductor memory device according to claim 13, wherein
the redundant wiring layer is formed on the same wiring layer as that of at least one of the first wiring and the second wiring of the memory cell layer.
15. The semiconductor memory device according to claim 13, wherein
a plurality of redundant wiring layers are provided, and
the redundant wirings are formed on the different redundant layers are connected to each other by the plurality of contacts.
16. The semiconductor memory device according to claim 13, wherein
the third wiring is orthogonal to the fourth wiring, and
the redundant wiring is formed into an L-shape having a portion extending in the same direction as the third wiring and a portion extending in the same direction as the fourth wiring.
17. The semiconductor memory device according to claim 16, wherein
the L-shaped redundant wiring is shifted in the same direction as the third wiring and in the same direction as the fourth wiring with respect to the other L-shaped redundant wiring adjacent to the redundant wiring.
18. The semiconductor memory device according to claim 15, wherein
the third wiring is orthogonal to the fourth wiring,
a part of the redundant wiring is formed into an L-shape having a portion extending in the same direction as the third wiring and a portion extending in the same direction as the fourth wiring, and
a part of the other redundant wiring is formed into a reed shape extending in the same direction as the third wiring or the fourth wiring.
19. The semiconductor memory device according to claim 13, wherein
the redundant wiring is provided between the adjacent memory blocks.
20. The semiconductor memory device according to claim 13, wherein
the contact is provided in a contact area between the adjacent memory blocks.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A hinge mechanism comprising:
first and second chock plates and an adjustable shaft, each of the chock plates including an aperture in the form of a figure eight, having similar first and second circular portions connected by a neck portion of a width less than the diameter of the circular portions, and the shaft longitudinally adjustable between a first retracted position in which the sections of the shaft aligned with each of the chock plates have a cross-section which corresponds to the circular portions of the aperture and a second extended position in which the section of the shaft aligned with each of the chock plates have a cross-section of a diameter which is less than the width of neck portion.
2. A hinge mechanism according to claim 1, the shaft comprising:
a set of two cam rams, one ram mounted at either end of a pivot shaft, each of the cam rams comprising a cylinder, a ram shaft extending through the cylinder and slideable therein and a circular ram plate mounted on a first end of the ram shaft, the ram shaft having a diameter is less than the width of neck portion and the cam plate having a cross-section which corresponds to one of the circular portions of the figure eight aperture.
3. An arrangement for the raising and lowering of a mast, which comprises an upper mast portion and a base, wherein the upper mast portion is rotatable about a horizontal pivot axis, located in the base of the mast, the arrangement comprising:
(i) docking means for restraining the upper mast portion against rotation;
(ii) attachment for attaching drive means for driving the docking means between a first engaged configuration wherein the upper mast portion is restrained against rotation and a second disengaged configuration wherein the upper mast portion is free to rotate; and
(iii) locking means selectable via an intermediate unlocked configuration between a first locked configuration wherein the docking means is engaged and a second unlocked configuration wherein the docking means is disengaged,
characterized in that the locking means comprises a hinge mechanism which comprises first and second chock plates and an adjustable shaft, each of the chock plates including an aperture in the form of a figure eight having similar first and second circular portions connected by a neck portion of a width less than the diameter of the circular portions and the shaft is longitudinally adjustable between a first retracted position in which the sections of the shaft aligned with each of the chock plates have a cross-section which corresponds to the circular portion of the aperture and a second extended position in which the sections of the shaft aligned with each of the chock plates have a cross-section of a diameter which is less than the width of neck portion.
4. An arrangement according to claim 3 characterized in that the shaft comprising:
a set of two cam rams, one ram mounted at either end of a pivot shaft, each of the cam rams comprising a cylinder, a ram shaft extending through the cylinder and slideable therein and a circular cam plate mounted on a first end of the ram shaft, the ram shaft having a diameter which is less than the width of neck portion and the cam plate having a cross-section which corresponds to a circular portion of the figure eight aperture.