Apparatuses including buried digit lines
Methods of forming semiconductor device structures include forming trenches in an array region and in a buried digit line end region, forming a metal material in the trenches, filling the trenches with a mask material, removing the mask material in the trenches to expose a portion of the metal material, and removing the exposed portion of the metal material. A plurality of conductive contacts is formed in direct contact with the metal material in the buried digit line end region. Methods of forming a buried digit line contact include forming conductive contacts physically contacting metal material in trenches in a buried digit line end region. Vertical memory devices and apparatuses include metallic connections disposed between a buried digit line and a conductive contact in a buried digit line end region.
1. An apparatus comprising a memory cell array comprising an array region and an end region proximate to the array region, wherein the memory cell array comprises:
at least one buried bit line extending in a first direction, the at least one buried bit line comprising a first portion in the array region and a second portion in the end region, the first portion comprising first connection parts, and the second portion comprising at least one second connection part;
pillar transistors in the array region, each of the pillar transistors in contact with an associated one of the first connection parts of the first portion of the at least one buried bit line;
buried word lines in the array region, each of the buried word lines extending in a second direction along a sidewall of an associated one of the pillar transistors, and the second direction being substantially perpendicular to the first direction;
at least one semiconductor pillar in the end region, the at least one semiconductor pillar in contact with the at least one second connection part of the second portion of the at least one buried bit line; and
at least one conductive connection in the end region, the at least one conductive connection protruding upwardly from the at least one second connection part of the second portion of the at least one buried bit line along a sidewall of the at least one semiconductor pillar.
2. The apparatus of claim 1 , wherein the memory cell array further comprises at least one conductive contact in the end region, the at least one conductive contact in contact with the at least one conductive connection.
3. The apparatus of claim 2 , wherein each of the at least one buried bit line, the at least one conductive connection and the at least one conductive contact comprises a metal.
4. The apparatus of claim 2 , wherein each of the buried word lines is higher in level than the at least one buried bit line.
5. The apparatus of claim 4 , wherein the at least one conductive connection protrudes upwardly higher than each of the buried word lines.
6. The apparatus of claim 1 , wherein the at least one semiconductor pillar includes a first recess region that is in contact with the at least one second connection part of the second portion of the at least one buried bit line.
7. The apparatus of claim 6 , wherein each of the pillar transistors comprises a lower portion, an upper portion and a middle portion between the lower portion and the upper portion, the lower portion including a second recess region that is in contact with an associated one of the first connection parts of the first portion of the at least one buried bit line.
8. The apparatus of claim 1 , wherein:
the at least one semiconductor pillar comprises a first lower portion of a first conductivity type, a first upper portion of the first conductivity type and a first middle portion of a second conductivity type between the first lower portion and the first upper portion, the first lower portion including a first recess region that is in contact with the at least one second connection part of the second portion of the at least one buried bit line; and
each of the pillar transistors comprises a second lower portion of the first conductivity type, a second upper portion of the first conductivity type and a second middle portion of the second conductivity type between the second lower portion and the second upper portion, the second lower portion including a second recess region that is in contact with an associated one of the first connection parts of the first portion of the at least one buried bit line.