Methods of forming microelectronic devices

A method of forming a microelectronic device, comprising:

• forming a first wafer comprising a semiconductor material, control logic devices including comprising portions of the semiconductor material, and oxide dielectric material covering the semiconductor material and the control logic devices;
• forming a second wafer comprising additional semiconductor material and additional oxide dielectric material over the additional semiconductor material;
• attaching the second wafer to the first wafer using oxide-oxide bonding between the additional oxide dielectric material and the oxide dielectric material;
• forming access devices using portions of the additional semiconductor material;
• forming word lines and digit lines operatively associated with the access devices;
• forming contact structures penetrating the word lines and the digit lines and in electrical communication with the control logic devices;
• forming capacitors over and in electrical communication with the access devices to form memory cells;
• and
• forming routing structures over the capacitors and in electrical communication with the memory cells and the control logic devices.

A method of forming a microelectronic device, comprising:

• forming a control circuitry structure comprising semiconductor material, control logic devices at least partially overlying the semiconductor material, and isolation material covering the semiconductor material and the control logic devices;
• forming an additional structure comprising additional semiconductor material and additional isolation material over the additional semiconductor material;
• bonding the additional isolation material of the additional structure to the isolation material of the control circuitry structure to form an assembly including the additional structure vertically overlying and attached to the control circuitry structure;
• and
• forming transistors comprising portions of the additional semiconductor material after forming the assembly;
• and
• forming capacitors vertically over and coupled to transistors to form a modified assembly including dynamic random access memory (DRAM) cells, the DRAM cells respectively comprising one of the transistors and one of the capacitors.