摘要:
A method for clearing an isolation collar from a first interior surface of a deep trench at a location above a storage capacitor while leaving the isolation collar at other surfaces of the deep trench. A barrier material is deposited above a node conductor of the storage capacitor. A layer of silicon is deposited over the barrier material. Dopant ions are implanted at an angle into the layer of deposited silicon within the deep trench, thereby leaving the deposited silicon unimplanted along one side of the deep trench. The unimplanted silicon is etched. The isolation collar is removed in locations previously covered by the unimplanted silicon, leaving the isolation collar in locations covered by the implanted silicon.
摘要:
An easily manufactured connecting structure from a node conductor of trench capacitor device is characterized at least in part by the presence of an isolation collar located above the node conductor, at least a portion of the collar having an exterior surface which is substantially conformal with at least a portion of an adjacent wall of the trench, a buried strap region in the trench above the node conductor, the strap region being bounded laterally by the isolation collar except at an opening in the collar. The connecting structure is preferably formed by a method involving clearing an isolation collar from a first interior surface of a deep trench at a location above a storage capacitor while leaving the isolation collar at other surfaces of the deep trench.
摘要:
A method of forming a vertical transistor. A pad layer is formed over a semiconductor substrate. A trough is formed through the pad layer and in the semiconductor substrate. A bit line is formed buried in the trough. The bit line is enclosed by a dielectric material. A strap is formed extending through the dielectric material to connect the bit line to the semiconductor substrate. The trough is filled above the bit line with a conductor. The conductor is cut along its longitudinal axis such that the conductor remains on one side of the trough. Wordline troughs are formed, substantially orthogonal to the bit line, above the semiconductor substrate. A portion of the conductor is removed under the wordline trough to separate the conductor into separate gate conductors. Wordlines are formed in the wordline trough connected to the separate gate conductors.
摘要:
A memory cell containing double-gated vertical metal oxide semiconductor field effect transistors (MOSFETs) and isolation regions such as shallow trench isolation, STI, regions that are self-aligned to the wordlines and bitlines of the cell are provided. The inventive memory cell substantially eliminates the backgating problem and floating well effects that are typically present in prior art memory cells. A method of fabricating the inventive memory cell is also provided.
摘要:
The distance between buried straps in a DRAM array of trench capacitor/vertical transistor cells is increased by offsetting adjacent cells by a vertical offset distance, so that the total distance between adjacent straps is increased without increasing the horizontal distance between cells.
摘要:
A memory cell containing double-gated vertical metal oxide semiconductor field effect transistors (MOSFETs) and isolation regions such as shallow trench isolation, STI, regions that are self-aligned to the wordlines and bitlines of the cell are provided. The inventive memory cell substantially eliminates the backgating problem and floating well effects that are typically present in prior art memory cells. A method of fabricating the inventive memory cell is also provided.
摘要:
A DRAM cell storage capacitor is formed above the bottom of a deep trench (DT) below an FET transistor. The DT has upper, central and lower portions with sidewalls. A capacitor plate electrode, surrounding the lower DT portion that is doped with a first dopant type, is separated by an interface from a well region surrounding the upper and central portions of the DT that are doped with an opposite dopant type. A source/drain region formed at the top of the cell is doped with the first dopant type. A node dielectric layer that covers the sidewalls and bottom of the lower and central portions of the DT is filled with a node electrode of the capacitor, doped with the first dopant type, fills the space inside the node dielectric layer in the lower part of the DT. Above a recessed node dielectric layer a strap region space is filled with a buried-strap conductor. An oxide (TTO) layer is formed over the node electrode and the buried-strap in the DT. A peripheral gate oxide layer, which coats sidewalls of the DT above the TTO, defines a space which is filled with the FET gate electrode. An outdiffusion region, doped with the first dopant type, is formed in the well region near the buried-strap. The cell has a first state and an opposite state of operation. A punch-through device, formed in the well between the outdiffusion region and the interface, provides a self-refreshing punchthrough current in the cell between the well and the plate in the first state of cell operation. A reverse bias junction leakage current occurs in the cell between the buried-strap and the P-well to refresh the opposite state of cell operation.
摘要:
A method for providing dual work function doping and borderless array diffusion contacts includes providing a semiconductor substrate, a gate insulator, a conductor on the gate insulator, an insulating cap on the conductor and insulating spacers on sidewalls of a portion of the conductor and the insulating cap. The method also includes doping portions of the semiconductor substrate and the conductor with a first conductive type and other portions with a second conductive type. The conductor may be annealed such that dopants of the first and second conductive types spread over the respective conductors.
摘要:
The present invention provides a vertical memory device formed in a silicon-on-insulator substrate, where a bitline contacting the upper surface of the silicon-on-insulator substrate is electrically connected to the vertical memory device through an upper strap diffusion region formed through a buried oxide layer. The upper strap diffusion region is formed by laterally etching a portion of the buried oxide region to produce a divot, in which doped polysilicon is deposited. The upper strap region diffusion region also provides the source for the vertical transistor of the vertical memory device. The vertical memory device may also be integrated with a support region having logic devices formed atop the silicon-on-insulator substrate.
摘要:
A method of fabricating a vertical field effect transistor (“FET”) is provided which includes a transistor body region and source and drain regions disposed in a single-crystal semiconductor-on-insulator (“SOI”) region of a substrate adjacent a sidewall of a trench. The substrate includes a buried insulator layer underlying the SOI region and a bulk region underlying the buried insulator layer. A buried strap conductively connects the SOI region to a lower node disposed below the SOI region and a body contact extends from the transistor body region to the bulk region of the substrate, the body contact being insulated from the buried strap.