In certain aspects, a method for forming a three-dimensional (3D) memory device is disclosed. A transistor is formed in a first region on a first side of a single crystalline silicon substrate. A step layer is formed in a second region on the first side of the single crystalline silicon substrate. A channel structure extending through a stack structure and in contact with the step layer is formed. The stack structure includes interleaved dielectric layers and conductive layers on the step layer. Part of the single crystalline silicon substrate that is in the second region is removed from a second side opposite to the first side of the single crystalline silicon substrate to expose the step layer from the second side.

First and second wells are formed in a semiconductor substrate. First and second trenches in the first second wells, respectively, each extend vertically and include a central conductor insulated by a first insulating layer. A second insulating layer is formed on a top surface of the semiconductor substrate. The second insulating layer is selectively thinned over the second trench. A polysilicon layer is deposited on the second insulating layer and then lithographically patterned to form: a first polysilicon portion over the first well that is electrically connected to the central conductor of the first trench to form a first capacitor plate, a second capacitor plate formed by the first well; and a second polysilicon portion over the second well forming a floating gate electrode of a floating gate transistor of a memory cell having an access transistor whose control gate is formed by the central conductor of the second trench.

Apparatus and methods are disclosed, including an apparatus that includes a number of tiers of a first semiconductor material, each tier including at least one access line of at least one memory cell and at least one source, channel and/or drain of at least one peripheral transistor, such as one used in an access line decoder circuit or a data line multiplexing circuit. The apparatus can also include a number of pillars of a second semiconductor material extending through the tiers of the first semiconductor material, each pillar including either a source, channel and/or drain of at least one of the memory cells, or a gate of at least one of the peripheral transistors. Methods of forming such apparatus are also described, along with other embodiments.

Provided is a method of manufacturing a memory device and a patterning method. The patterning method includes following steps. A control structure including stop layers and oxide layers stacked alternately, a hard mask layer, and a mask pattern are sequentially formed on a target layer. A photoresist layer is formed in the mask pattern on the hard mask layer. A portion of the hard mask layer and a portion of the control structure are removed to form first openings by using the photoresist layer and the mask pattern as a mask. The photoresist layer and the hard mask layer are removed to form a second opening having a bottom surface higher than that of the first openings. At least one etching process is performed so that the first and second openings extend into and divide the control structure and the target layer into stack structures.

Provided is a method of manufacturing a memory device and a patterning method. The patterning method includes following steps. A control structure including stop layers and oxide layers stacked alternately, a hard mask layer, and a mask pattern are sequentially formed on a target layer. A photoresist layer is formed in the mask pattern on the hard mask layer. A portion of the hard mask layer and a portion of the control structure are removed to form first openings by using the photoresist layer and the mask pattern as a mask. The photoresist layer and the hard mask layer are removed to form a second opening having a bottom surface higher than that of the first openings. At least one etching process is performed so that the first and second openings extend into and divide the control structure and the target layer into stack structures.

In certain aspects, a three-dimensional (3D) memory device includes a memory stack including interleaved conductive layers and dielectric layers, a channel structure extending through the memory stack, and a through array contact (TAC) extending through the memory stack. Edges of the conductive layers along a sidewall of the TAC are recessed. The TAC includes a conductor layer and a spacer over the sidewall of the TAC.

In certain aspects, a three-dimensional (3D) memory device includes a memory stack including interleaved conductive layers and dielectric layers, a channel structure extending through the memory stack, and a through array contact (TAC) extending through the memory stack. Edges of the conductive layers along a sidewall of the TAC are recessed. The TAC includes a conductor layer and a spacer over the sidewall of the TAC.

A flash includes a substrate. Two gate structures are disposed on the substrate. Each of the gate structures includes a floating gate and a control gate. The control gate is disposed on the floating gate. An erase gate is disposed between the gate structures. Two word lines are respectively disposed at a side of each of the gate structures. A top surface of each of the word lines includes a first concave surface and a sharp angle. The sharp angle is closed to a sidewall of the word line which the sharp angle resided. The sidewall is away from each of the gate structures. The sharp angle connects to the first concave surface.

A flash includes a substrate. Two gate structures are disposed on the substrate. Each of the gate structures includes a floating gate and a control gate. The control gate is disposed on the floating gate. An erase gate is disposed between the gate structures. Two word lines are respectively disposed at a side of each of the gate structures. A top surface of each of the word lines includes a first concave surface and a sharp angle. The sharp angle is closed to a sidewall of the word line which the sharp angle resided. The sidewall is away from each of the gate structures. The sharp angle connects to the first concave surface.

According to one embodiment, a semiconductor memory device includes: a first stacked body that includes a memory region, a stepped region, and a connection region arranged in a first direction; a plurality of first pillars that is disposed in the memory region, extends in the first stacked body in the stacking direction; a plurality of second pillars that includes a second insulating layer, has a layer structure different from a layer structure of the first pillars, and extends in the stacking direction in a position overlapping a stepped portion disposed in the stepped region in the stacking direction; and a plurality of third pillars that extends in the first stacked body in the stacking direction, and has a same layer structure as the layer structure of the first pillars, at least a part of the plurality of third pillars being disposed in the connection region.