Embodiments of the present application disclose a semiconductor structure, a formation method thereof and a memory. The semiconductor structure includes: a substrate; a channel located in the substrate, the channel being configured to form a gate structure; and a convex portion arranged on an inner wall of the channel. The embodiments of the present application can increase a channel length and solve a short-channel effect.

A semiconductor memory device includes active regions including first impurity regions and second impurity regions, word lines on the active regions and extended in a first direction, bit lines on the word lines and extended in a second direction crossing the first direction, the bit lines being connected to the first impurity regions, first contact plugs between the bit lines, the first contact plugs being connected to the second impurity regions, landing pads on the first contact plugs, respectively, and gap-fill structures filling spaces between the landing pads, top surfaces of the gap-fill structures being higher than top surfaces of the landing pads.

A semiconductor device and a method of fabricating a semiconductor device, the device including a semiconductor substrate that includes a trench defining an active region; a buried dielectric pattern in the trench; a silicon oxide layer between the buried dielectric pattern and an inner wall of the trench; and a polycrystalline silicon layer between the silicon oxide layer and the inner wall of the trench, wherein the polycrystalline silicon layer has a first surface in contact with the semiconductor substrate and a second surface in contact with the silicon oxide layer, and wherein the second surface includes a plurality of silicon grains that are uniformly distributed.

Disclosed are DRAM devices and methods of forming DRAM devices. One method may include forming a plurality of trenches and angled structures, each angled structure including a first sidewall opposite a second sidewall, wherein the second sidewall extends over an adjacent trench. The method may include forming a spacer along a bottom surface of the trench, along the second sidewall, and along the first sidewall, wherein the spacer has an opening at a bottom portion of the first sidewall. The method may include forming a drain in each of the angled structures by performing an ion implant, which impacts the first sidewall through the opening at the bottom portion of the first sidewall. The method may include removing the spacer from the first sidewall, forming a bitline over the spacer along the bottom surface of each of the trenches, and forming a series of wordlines along the angled structures.

A method of forming a semiconductor memory device includes the following steps. First of all, a substrate is provided, and a plurality of gates is formed in the substrate, along a first direction. Next, a semiconductor layer is formed on the substrate, covering the gates, and a plug is then in the semiconductor layer, between two of the gates. Then, a deposition process is performed to from a stacked structure on the semiconductor layer. Finally, the stacked structure is patterned to form a plurality of bit lines, with one of the bit lines directly in contact with the plug.

A semiconductor device includes a substrate, a pair of source/drain regions, a metal-containing layer, and a gate structure. The substrate includes a trench. The source/drain regions are disposed in the substrate on opposite sides of the trench. The metal-containing layer is disposed under the trench, wherein the metal-containing layer includes a metal silicide layer, and the metal-containing layer and the substrate on opposite sidewalls of the trench collectively form the channel region of the semiconductor device. The gate structure is disposed in the trench. The gate structure includes a gate dielectric layer disposed on opposite sidewalls of the trench, a buffer layer disposed on the metal-containing layer, and a gate conductive layer disposed on the buffer layer and filling in the trench.

A semiconductor device includes a semiconductor substrate and word line structures. A plurality of active areas are formed in the substrate, and the plurality of active areas are isolated by an isolation structure. The isolation structure includes first areas and second areas. A dimension of the second areas is larger than that of the first areas in first direction. The word line structures are below a surface of the substrate and extend in first direction. The word line structures penetrate the isolation structure and the plurality of active areas. A word line structure includes first sub-word line structures located in first areas and second sub-word line structures located in second areas. The first sub-word line structures have first dimension in second direction, and the second sub-word line structures have second dimension at least larger than first dimension in second direction. The second direction forms an included angle with first direction.

Embodiments relate to a semiconductor structure and a method for fabricating. The semiconductor structure includes: a substrate, word lines, bit lines, and word line isolation structures. Active pillars arranged in an array are provided on a surface of the substrate, and the active pillars include channel regions, and a top doped region positioned on an upper side of the channel region and a bottom doped region positioned on a lower side of the channel region. The word lines extend along a first direction and surround the channel regions of a row of the active pillars arranged along the first direction. The bit lines extend along a second direction and are electrically connected to the bottom doped regions of a column of the active pillars arranged along the second direction, and in a direction facing away from the surface of the substrate.

A semiconductor structure and a method for forming the same are provided. The method for forming the semiconductor structure includes: providing a substrate; etching the substrate to form multiple active areas, trenches each positioned between adjacent active areas, and air gaps positioned below the active areas; and forming a filler layer filling at least each of the trenches.

A method for forming a transistor structure includes steps as follows: A substrate with an original surface is prepared. Next a gate conductive region is formed, wherein at least a portion of the gate conductive region is disposed below the original surface, and a bottom wall and sidewalls of the gate conductive region is surrounded by a gate dielectric layer. Then, a first conductive region is formed, wherein a bottom wall of the first conductive region is aligned or substantially aligned with a top wall of the gate conductive region.