A semiconductor structure includes a semiconductor substrate including a first active region and a chop region. The semiconductor structure also includes a source/drain region disposed in the first active region, an isolation structure disposed in the chop region, and a gate structure extending at least across the isolation structure in the chop region. The gate structure includes a gate electrode layer and a gate lining layer lining on the gate electrode layer. The gate lining layer includes a first portion having an upper surface that is lower than a bottom surface of the source/drain region.

The present disclosure provides a method for preparing a semiconductor memory device with air gaps between conductive features. The method includes forming an isolation layer defining a first active region in a substrate; forming a first doped region in the first active region; forming a first word line buried in a first trench adjacent to the first doped region; and forming a high-level bit line contact positioned on the first doped region; forming a first air gap surrounding the high-level bit line contact. The forming of the first word line comprises: forming a lower electrode structure and an upper electrode structure on the lower electrode structure. The forming of the upper electrode structure comprises: forming a source layer substantially covering a sidewall of the first trench; forming a conductive layer on the source layer; and forming a work-function adjustment layer disposed between the source layer and the conductive layer.

Methods for DRAM device with a buried word line are described. The method includes forming a metal cap layer and a molybdenum conductor layer in a feature on a substrate. The method includes depositing the metal cap layer on the substrate by physical vapor deposition (PVD) and depositing the molybdenum conductor layer by atomic layer deposition (ALD) on the metal cap layer.

An apparatus includes: a semiconductor substrate; an isolation region in the semiconductor substrate, the isolation region including an isolation trench filled with an insulating material therein; a plurality of island-shaped active regions in the semiconductor substrate surrounded by the isolation region; and a buried word-line having a bottom, the buried word-line at least passing across the isolation region between the plurality of active regions; wherein the isolation trench includes upper, middle and lower portions, each of the upper and lower portions has a substantially flat surface and the middle portion has a bulged surface.

A semiconductor device includes a substrate having at least a trench formed therein. A conductive material fills a lower portion of the trench. A barrier layer is between the conductive material and the substrate. An insulating layer is in the trench and completely covers the conductive material and the barrier layer, wherein a portion of the insulating layer covering the barrier layer has a bird's peak profile.

A semiconductor structure includes a two-dimensional array of unit cell structures overlying a substrate. Each unit cell structure includes an active layer, a gate dielectric underlying the active layer, two gate electrodes underlying the gate dielectric, and two source electrodes and a drain electrode overlying the active layer. Word lines underlie the active layers. Each unit cell structure includes portions of a respective set of four word lines, which includes two word lines that are electrically connected to two electrodes in the unit cell structure and two additional word lines that are electrically isolated from the two electrodes in the unit cell structure.

Provided is a memory device including a substrate, a plurality of bit-line structures, a plurality of bit-line contacts, and a plurality of protective structures. The substrate has a plurality of active areas. The plurality of bit-line structures are disposed on the substrate in parallel along a X direction. The plurality of bit-line contacts are respectively disposed at overlaps of the plurality of bit-line structures and the plurality of active areas, and electrically connect the plurality of bit-line structures and the plurality of active areas. The plurality of protective structures are disposed at least on a first sidewall and a second sidewall of the plurality of bit-line contacts. A method of forming a memory device is also provided.

Methods of forming memory devices are described. A molybdenum silicide nucleation layer is formed, and the substrate is soaked in a titanium precursor prior to a bulk molybdenum gap fill process. In other embodiments, a molybdenum silicide film is formed in a first process cycle and a second process cycle is performed where the substrate is exposed to a titanium precursor. In further embodiments, a substrate having at least one feature thereon is exposed to a first titanium precursor and a nitrogen-containing reactant. The substrate is then soaked in a second titanium precursor, and then is exposed to a first molybdenum precursor followed by exposure to a silane to form a molybdenum silicide layer on a surface of the substrate.

A semiconductor device includes bit line structures disposed on a substrate, each bit line structure comprising a bit line and an insulating spacer structure, buried contacts which fill lower portions of spaces between bit line structures in the substrate, and landing pads which fill upper portions of the spaces, extend from upper surfaces of the buried contacts to upper surfaces of the bit line structures, and are spaced apart from each other by insulating structures. A first insulating structure is disposed between a first landing pad and a first bit line structure. The first insulating structure includes a sidewall extending along a sidewall of the first landing pad toward the substrate. In a direction extending toward the substrate, the sidewall of the first insulating structure gets closer to a first sidewall of the first bit line structure.

Embodiments of the present disclosure provide a forming method of a semiconductor structure and a semiconductor structure. The forming method includes: providing a base, the base includes a central region and dummy regions, and the central region includes a molding region and cutting regions; forming multiple spaced core pillars on the base; forming an initial mask layer surrounding and covering a sidewall of each core pillar on the base; removing the initial mask layers located in each cutting region to form multiple spaced mask sidewall strips in the molding region, and retaining at least one of the initial mask layers in each dummy region as a ring-shaped sidewall; removing the core pillars located in the central region and the dummy regions; and etching the base to form multiple functional structures, and etching the base to form dummy functional structures on two sides of the multiple functional structures.