Abstract: An apparatus comprising a memory array comprising word lines, bit lines, and memory cells, one or more of the memory cells coupled to an associated word line and an associated bit line and comprising active areas and shallow trench isolation (STI) structures adjacent to a base material. The word lines are in the active areas and STI structures and bit line structures are adjacent to the active areas and the STI structures and oriented perpendicular to the word lines. The bit line structures comprise bit lines and bit contacts. Cell contact structures are laterally adjacent to the bit line structures and comprise cell contacts comprising an epitaxial semiconductive material. One or more of the bit contacts and the epitaxial semiconductive material comprise a doped epitaxial silicon material, the doped epitaxial silicon material exhibiting a relatively greater dopant concentration in a [110] crystal orientation than in a [100] or [111] crystal orientation. Methods of forming the apparatus are also disclosed.

Abstract: Some embodiments include a method in which an assembly is formed to have a first silicon-dioxide-containing-material and a second silicon-dioxide-containing-material. The first silicon-dioxide-containing-material has a higher concentration of dopant therein than does the second silicon-dioxide-containing-material. The first silicon-dioxide-containing-material is selectively removed relative to the second silicon-dioxide-containing-material using a mixture which includes hydrofluoric acid, a second acid and an organic solvent. The organic solvent may include at least one ester and/or at least one ether. The second acid may have a pKa of less than about 5.

Abstract: Some embodiments include a method in which an assembly is formed to have a first silicon-dioxide-containing-material and a second silicon-dioxide-containing-material. The first silicon-dioxide-containing-material has a higher concentration of dopant therein than does the second silicon-dioxide-containing-material. The first silicon-dioxide-containing-material is selectively removed relative to the second silicon-dioxide-containing-material using a mixture which includes hydrofluoric acid, a second acid and an organic solvent. The organic solvent may include at least one ester and/or at least one ether. The second acid may have a pKa of less than about 5.