Relaxed-pitch method of aligning active area to digit line
AssigneeMicron Technology, Inc.
InventorAnton P. Eppich
Life of this patent
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Abstract
According to one aspect of the invention, a memory device is disclosed. The memory device comprises a substantially linear active area comprising a source and at least two drains defining a first axis. The memory device further comprises at least two substantially parallel word lines, at least a portion of a first word line located between a first drain and the source, and at least a portion of a second word line located between a second drain and the source, which word lines define a second axis. The memory device further comprises a digit line coupled to the source, wherein the digit line forms a substantially zig-zag pattern.
Claims21
A method of manufacturing a memory device, the method comprising:
- defining at least one substantially linear active area within a substrate, said active area comprising a shared source, a first drain, and a second drain, the shared source, the first drain and the second drain defining a first axis;
- defining a first gate between the shared source and the first drain;
- defining a second gate between the shared source and the second drain;
- defining at least one pair of substantially parallel word lines within the substrate by a pitch-doubling technique such that each of the pair has a first width, said pair of word lines defining a second axis lengthwise wherein a first word line of the pair is coupled to the first gate, wherein a second word line of the pair is coupled to the second gate, wherein a third axis runs perpendicular to the second axis;
- and
- defining at least one digit line above the substrate in a substantially zig-zag pattern, wherein the digit line has a width about double that of the first width, wherein at least a portion of the digit line extends above and is coupled to the shared source, the portion defining a fourth axis, wherein an acute angle between the third axis and the fourth axis is within the range of 20° to 30°.
A method of manufacturing a memory device, the method comprising:
- forming two or more elongated active areas each having an axis along its length, each of the elongated active areas having a shared source, two drains, and two gates;
- forming four or more storage capacitors for storage for the DRAM device, wherein a node of a storage capacitor is coupled to a drain of the elongated active areas;
- forming four or more elongated word lines that run parallel to each other, each having an axis along its length and a pair of which extend adjacent a corresponding one of the elongated active areas, wherein the four or more elongated word lines are approximately half a width of a digit line;
- and
- forming one or more digit lines, each having a zigzag pattern such that a digit line undulates above and below an imaginary center axis, wherein the center axis is perpendicular to the axes of the elongated word lines, the zigzag pattern comprising a repeating pattern of at least a first linear portion and a second linear portion, wherein the first linear portion crosses the center axis from a first side of the center axis, and the second linear portion crosses the center axis from a second side of the center axis, wherein the first linear portion and the second linear portion cross the center axis with acute angles of 20° to 30°.
Dependencies are inferred from the claim text.