Vanguard International Semiconductor Corporation

Industrial Technology Research Institute

Macronix International Co., Ltd.

Chih-Yuan Lu

Horng-Huei Tseng

Howard C Kirsch

Janmye Sung

Min-hwa Chi

Yi-Chou Chen

Yi Chou Chen

Hsiao-Chin Tuan

Howard Clayton Kirsch

Horng Huei Tseng

Hsiang-Lan Lung

Wen-Jer Tsai

Nicky C Lu

Jan Mye Sung

Hsiang-Ming J Chou

Hsing-Hai Chen

Ching-Tzong Sune

Li-Hsin Chuang

JanMye Sung

Hsiao-Pin Tseng

A memory core includes a bit line and a word line. The memory core also includes a core cell in electrical communication with the word line and the bit line. The core cell includes a threshold changing material. The threshold changing material is programmed to enable access to the core cell based upon a voltage applied to the word line. Methods for accessing a memory core cell also are described.

Transistor-free random access memory

A multilevel memory core includes a word line and a bit line. The multilevel memory core also includes a core cell in electrical communication with the word line and the bit line. The core cell includes a threshold changing material. The threshold changing material is programmed to define multiple levels for storage where each of the multiple levels for storage is associated with a corresponding threshold voltage. Methods for reading the multilevel memory core also are described.

Multi-level memory device and methods for programming and reading the same

Roughly described, a phase-change memory such as a chalcogenide-based memory is programmed optically and read electrically. No complex electrical circuits are required for programming the cells. On the other hand, this memory can be read by electrical circuitry directly. The read out speed is much faster than for optical disks, and integrated circuit chips made this way are more compatible with other electrical circuits than are optical disks. Thus memories according to the invention can have simple, low power-consuming, electrical circuits, and do not require slow and power-hungry disk drives for reading. The invention therefore provides a unique low power, fast read/write memory with simple electrical circuits.

Laser programmable electrically readable phase-change memory method and device

Methods and systems are provided for forming an electrical interconnect layer between two layers of an integrated circuit. The interconnect layer is formed using a material having a first electrical conductivity corresponding to a first state and a second electrical conductivity corresponding to a second state, where the first electrical conductivity is different from the second electrical conductivity. An area of the material of the interconnect layer may be selected, for example, using a mask. Then energy may be applied to the selected area to change the electrical conductivity of the material in the selected area of the interconnect layer. Thus, the present invention may be used to implement optical memory devices which may be read by an electrical circuit.

Method and system for lithography using phase-change material

A method of creating a Capacitor Over Metal, (COM), stacked capacitor structure, for a DRAM device, has been developed. The process features creating metal interconnect structures, prior to the creation of the COM, stacked capacitor structure. The metal structures are connected to underlying regions of the semiconductor substrate via polysilicon contact plugs, and metal studs, while the same metal structures are connected to overlying structures, such as the COM stacked capacitor structure, via additional metal studs. Planarization of passivating insulator layers, result in topology reductions, reducing the severity of opening via holes to specific metal structures.

Capacitor over metal DRAM structure

A clamp for fixturing a substrate when forming and thermal processing upon the substrate a thermally flowable layer. The clamp is formed from a backing member connected to a top member through a mechanical means. The backing member and the top member are sized such that a substrate may be clamped between the backing member and the top member. A portion of the top member overlaps the substrate and leaves exposed a first portion of the substrate when the substrate is clamped between the backing member and the top member. The top member has a cross-sectional profile such that a thermally flowable layer residue formed upon the top member when a thermally flowable layer is formed upon the substrate will not flow from the top member and bridge to the thermally flowable layer when the thermally flowable layer is thermally processed.

Substrate clamp design for minimizing substrate to clamp sticking during thermal processing of thermally flowable layers

A method for manufacturing an array of stacked capacitor is described that utilizes the sidewall of the capacitor node contact to increase the capacitance on a dynamic random access memory (DRAM) cell. The area occupied by the stacked capacitor is also restricted to the area over the FET source/drain area, thereby providing for the further reduction of the cell size. The method using a single mask level to form node contact openings in a thick insulating layer over the source/drain areas used for the node contact. A doped polysilicon layer is deposited filling the node contact openings and conformally coating the substrate. The polysilicon layer is oxidized to the thick insulating layer but not in the node contact openings. The oxidized portion of the polysilicon layer and the thick insulating layer are removed concurrently in a wet etch leaving free standing pillar-shaped bottom electrodes that also serve as the node contacts. The array of pillar-shaped stacked capacitors are completed by forming a interelectrode dielectric layer on the bottom electrodes and then depositing and patterning another doped polysilicon to form the top electrodes.

High density dynamic random access memory cell structure having a polysilicon pillar capacitor

An improved dynamic random access memory (DRAM) cell using a novel buried horizontal trench capacitor was achieved. A capacitor trench is etched in a silicon substrate. A first high-k dielectric layer is formed on the trench surface, and the trench is filled with a first polysilicon layer and polished back. A second high-k dielectric is deposited and patterned over the polySi-filled trench. A P,epitaxy is grown on the substrate that also grows inward over the trench, while an amorphous silicon layer of decreasing top surface area grows on the dielectric over the trench. A field oxide is formed in the epi surrounding and isolating a device area aligned over the trench capacitor. A node contact hole is etched in the epi/amorphous Si to the capacitor and has an oxide liner on the sidewall. A second polySi is deposited and etched back to form the node contact to the buried trench capacitor. The gate electrode (access transistor) is formed on the epi layer over the capacitor, and adjacent to the node contact which is connected to one of the two FET source/drain (S/D) areas, while the second S/D is connected to a bit line. The surface over the cell, free for the bit line, and the FET over the capacitor reduces the cell size, while the buried horizontal trench capacitor increases capacitance.

Dynamic random access memory (DRAM) cell having a buried horizontal trench capacitor by a novel fabrication method

A process for fabricating a DRAM cell, with an area equal to five times the minimum feature, squared, (5F,), has been developed. The process features the use of selectively formed, N&plus; single crystalline, silicon plugs, on underlying source/drain regions. The N&plus; single crystalline, silicon plugs, epitaxial deposited, are used to connect overlying crown shaped capacitor structures, to underlying source/drain region, as well as to connect a bit line metal structure, to another source/drain region.

Method to fabricate a DRAM cell with an area equal to five times the minimum used feature, squared

A method for fabricating a DRAM cell, on a SOI layer, is described, featuring the incorporation of a two dimensional, trench capacitor structure, for increased DRAM cell signal, and the use of a polysilicon storage node structure to connect the SOI layer to the semiconductor substrate, to eliminate a floating body effect. A two dimensional trench is created by initially forming a vertical trench, through the SOI layer, through the underlying insulator layer, and into the semiconductor substrate. An isotropic etch is than performed to laterally remove a specific amount of insulator layer, exposed in the vertical trench, creating the lateral component of the two dimensional trench. A deposited polysilicon layer, coating the sides of the two dimensional trench, is used as the storage node structure, for the two dimensional, trench capacitor structure, while also connecting the SOI layer to the semiconductor substrate.

Method for fabricating a DRAM cell structure on an SOI wafer incorporating a two dimensional trench capacitor

The present invention provides a method for fabricating a multiple pillar shaped capacitor which has pillars of a smaller dimension than the resolution of the photolithography tool. The invention has two embodiments for forming the pillars and third embodiment for patterning a conductive layer into discrete bottom electrodes. The method begins by forming a conductive layer on a first planarization layer. For the first embodiment, the pillars are formed using a photolithography mask with a pattern of spaced transparent areas. The dimensions of the spaced transparent areas and distances between the spaced transparent areas are smaller that the resolution of the lithographic tool. Spaced oxide islands are formed with the mask and are used as an etch mask to form spaced pillars from the conductive layer. The second embodiment for forming the pillars involves using small titanium silicide islands as an etch mask to define the pillars. The third embodiment uses two resist layers and a photo mask shifting (offset) technique to form small spaces between the electrodes. Lastly, a capacitor dielectric layer and a top electrode are formed over the bottom electrodes thereby completing the capacitor with a pillar structure.

Method for forming a capacitor with a multiple pillar structure

A method and design for stitching polysilicon wordlines to straps formed of interconnected metal line segments formed in two or more metallization levels. Each strap comprises a continuous conductive metal line passing alternatively from one metal layer to another in a selected sequence. The sequence of segments in each strap alternates in phase with the sequence in next nearest neighbor straps but may be in phase with second nearest neighbor straps. Thereby the pitch of strap segments on each metallization level is at least twice that of the subjacent polysilicon wordlines. The total length of each metal in each strap is the same in all straps. This arrangement allows the use of metals having different resistivities in each strap with all the straps having identical overall resistance. The metals used in the two or more levels may also have different minimum design rules without compromising the identical overall performance of all the straps. In a second embodiment a method and design is described for doubling the length of polysilicon sub-wordlines in a sub-wordline memory array without reducing performance by connecting sub-wordline to sub-wordline decoders by metal straps connected to the sub-wordlines midpoints.

Design for high density memory with relaxed metal pitch

Method for fabricating a DRAM cell structure on an SOI wafer

An improved DRAM cell using a novel buried reservoir capacitor is achieved. The method forms an array of N.sup.+ doped regions in a substrate. P-wells are formed in an epitaxy layer on the substrate. A field oxide (FOX) is formed surrounding the device areas aligned over the N.sup.+ regions. Holes are etched in the epi layer to the N.sup.+ regions, and a selective wet etch removes the N.sup.+ doped regions to form cavities. A thin dielectric layer is deposited on the cavity walls, and an N.sup.+ polysilicon layer is deposited and polished back to form the buried reservoir capacitors. The N.sup.+ polysilicon in the holes forms the capacitor node contacts for the FETs in the device areas. The array of DRAM cells is completed by growing a gate oxide, depositing and patterning a first polycide layer to form FET gate electrodes on the device areas over the capacitors, thereby providing increased capacitance while reducing the cell area. Lightly doped source/drain (LDD) areas, sidewall spacers and heavily doped source/drain contacts are formed for the FETs. A node strap is formed between one source/drain contact and the node contact to make good electrical contact. An insulating layer is deposited having bit line contact holes, and a second polycide layer is patterned to form the bit lines for the DRAM.

Growing community of inventors

Hsinchu, Taiwan

Chih-Yuan Lu