Abstract: A stacked surrounding reintrant wall capacitor (SSRWC) using a modified stacked capacitor storage cell fabrication process. The SSRWC is made up of polysilicon structure, having an elongated v-shaped cross-section, located at a buried contact and extending to an adjacent storage node overlaid by polysilicon with a dielectric sandwiched in between. The addition of the polysilicon structure increases storage capability 50% without enlarging the surface area defined for a normal stacked capacitor cell.

Abstract: A mushroom double stacked capacitor (mushroom cell) using a modified stacked capacitor storage cell fabrication process. The mushroom cell is made up of polysilicon structure, having a mushroom extended V-shaped cross-section. The storage node plate of the mushroom cell is overlaid by polysilicon with a dielectric sandwiched in between and connects to an access device's active area via a buried contact. The plate extends to an adjacent storage node but is isolated from the adjacent node by less than the critical resolution dimension of a given lithographic technology. The shape of the polysilicon structure increases storage capability 200% or more without enlarging the surface area defined for a normal buried digit line stacked capacitor cell.

Abstract: A DRAM fabrication process is disclosed for constructing a reduced resistance digit-line. The digit-line is so constructed as to maintain low resistance as it crosses the gaps between word-lines. By bridging gaps having a dimension less than or falling below a calculated critical gap spacing, and following the contours of gaps having a dimension greater or falling above that critical gap dimension, the digit-line resistance can be minimized.

Abstract: An existing stacked capacitor fabrication process is modified to construct a three-dimensional stacked capacitor, referred to as a Double Ring Stacked Cell or DRSC. The DRSC design defines a capacitor storage cell that in the present invention is used in a DRAM process. The DRSC is made up of a polysilicon storage node structure having circular polysilicon ringed upper portion centered about a lower portion that makes contact to an active area via a buried contact. The polysilicon storage node structure is overlaid by polysilicon with a dielectric sandwiched in between to form a completed DRSC capacitor. The novel 3-dimensional shaped polysilicon storage node plate having double polysilicon rings, allows substantial capacitor plate surface area of 200% or more to be gained at the storage node over that of a conventional STC.

Abstract: A stacked textured container capacitor (STCC) using a modified stacked capacitor storage cell fabrication process. The STCC is made up of a texturized polysilicon structure, having an elongated u-shaped cross-section, located at a buried contact and extending to an adjacent storage node overlaid by polysilicon with a dielectric sandwiched in between. With the 3-dimensional shape and texturized surface of a polysilicon storage node plate substantial capacitor plate surface area of 200% or more is gained at the storage node.

Abstract: This invention relates to semiconductor circuit memory storage devices and more particularly to a process to develop three-dimensional stacked cell capacitors using a PZT ferroelectric material as a storage cell dielectric for use in high-density dynamic random access memory (DRAM) arrays. The present invention employs using PZT ferroelectric for the storage cell dielectric in three-dimensional stacked capacitor technology and develops an existing stacked capacitor fabrication process to construct a PZT three-dimensional stacked capacitor cell (the EFSC) that will allow denser storage cell fabrication with minimal increases of overall memory array dimensions. A capacitance gain of 3 to 10X or more over that of a conventional 3-dimensional storage cell is gained by using PZT ferroelectric as the storage cell dielectric.

Abstract: A method is disclosed for forming a capacitor on a semiconductor wafer. A first electrically conductive layer is applied atop the wafer and engages exposed active areas. A first dielectric layer is next applied. The first dielectric and conductive layers are then patterned to define an outline for the lower capacitor plate. A second dielectric layer, having an etch rate which is slower than the first, is then applied and planarized or otherwise etched down to the first dielectric layer. The first dielectric layer is then etched down to the first conductive layer to produce upwardly projecting walls of second dielectric material surrounding the lower capacitor plate outline. A second electrically conductive layer is then applied. It is then anisotropically etched to provide a first electrically conductive wall extending upwardly from the first conductive layer. A third dielectric layer is then applied.

Abstract: A double dynamic random access memory (DRAM) cell comprising two vertically stacked access transistors and storage capacitors. A first access transistor is formed on a silicon substrate. A seed contact to the first access transistor is then utilized for growing an intermediate silicon substrate by Confined Lateral Selective Epitaxial Overgrowth (CLSEG). A second access transistor is formed upon the intermediate silicon substrate. A storage capacitor for the first access transistor may be formed as a trench capacitor in the silicon substrate. A storage capacitor for the second access transistor may be stacked on the second access transistor. A common buried bit line connects the two access transistors.

Abstract: An existing stacked capacitor fabrication process is modified to construct a three-dimensional stacked capacitor, referred to hereinafter as a stacked E cell or SEC. The SEC design defines a capacitor storage cell that in the present invention is used in a DRAM process. The SEC is made up of a polysilicon storage node structure having an E-shaped cross-sectional upper portion and a lower portion making contact to an active area via a buried contact. The polysilicon storage node structure is overlaid by polysilicon with a dielectric sandwiched in between to form a completed SEC capacitor. With the 3-dimensional shape and a texturized surface of a polysilicon storage node plate, substantial capacitor plate surface area of 3 to 5X is gained at the storage node.

Abstract: A method is disclosed for forming a capacitor on a semiconductor wafer which utilizes top and back sides of a capacitor node for capacitance maximization. First and second dielectric layers, having different etch rates, are applied atop the wafer, and a contact opening is etched therethrough. Poly is applied and etched to begin formation of one node of the capacitor. A layer of oxide is then formed atop the poly capacitor node. The first dielectric layer is then etched, leaving a projecting or floating capacitor node which is surrounded by the second dielectric material and oxide formed thereatop. The surrounding material is then etched, the capacitor dielectric applied, and the poly of the second capacitor nod applied and selectively etched.

Abstract: A process for creating a DRAM array having feature widths that transcend the resolution limit of the employed photolithographic process using only five photomasking steps.

Abstract: The present invention utilizes a wet or vapor isotropic etchback process of carefully controlled duration to create a field-effect transistor having reduced-slope, staircase-profile sidewall spacers formed from a pair of TEOS oxide layers. The spacer's reduced sidewall slope and staircase profile facilitates digit line deposition and aids in reducing the existence of short-prone polysilicon stringers.