Sandisk 3d LLC

Sandisk Corporation

Matrix Semiconductor, Inc.

Calvin K Li

Christopher John Petti

Kang-Jay Hsia

James Montague Cleeves

Michael A Vyvoda

Vivek Subramanian

N Johan Knall

Yung-Tin Chen

Paul Wai Kie Poon

En-Hsing Chen

Samuel Vance Dunton

A method of forming a memory cell is provided. The method includes forming a first pillar-shaped element that includes a first semiconductor material, forming a first opening self-aligned with the first pillar-shaped element, and depositing a second semiconductor material in the first opening to form a second pillar-shaped element above the first pillar-shaped element. Other aspects are also provided.

Method of fabricating a self-aligning damascene memory structure

An integrated circuit including vertically oriented diode structures between conductors and methods of fabricating the same are provided. Two-terminal devices such as passive element memory cells can include a diode steering element in series with an antifuse and/or other state change element. The devices are formed using pillar structures at the intersections of upper and lower sets of conductors. The height of the pillar structures are reduced by forming part of the diode for each pillar in a rail stack with one of the conductors. A diode in one embodiment can include a first diode component of a first conductivity type and a second diode component of a second conductivity type. A portion of one of the diode components is divided into first and second portions with one on the portions being formed in the rail stack where it is shared with other diodes formed using pillars at the rail stack.

Non-volatile memory arrays comprising rail stacks with a shared diode component portion for diodes of electrically isolated pillars

A method of forming a memory cell is provided, the method including forming a first pillar-shaped element comprising a first semiconductor material, forming a first mold comprising an opening self-aligned with the first pillar-shaped element, and depositing a second semiconductor material in the opening to form a second pillar-shaped element above the first pillar-shaped element. Other aspects are also provided.

A mask is reused to form the same pattern in multiple layers in semiconductor processing. Reference marks that allow alignment accuracy to be checked are also formed with the mask. The manner of using the mask advantageously mitigates interference between reference marks in different layers.

Mask reuse in semiconductor processing

Test structures are formed during semiconductor processing. The test structures allow performance characteristics to be monitored as the process proceeds. The test structures are formed with a single mask that is used in a manner that also allows alignment marks to be formed which do not interfere with one another as subsequent levels are patterned. The manner of using the mask also allows different types of test structures having different features to be formed. The different types of test structures can provide insight into performance characteristics of different types of devices.

Test structure formation in semiconductor processing

A method is provided to form densely spaced metal lines. A first set of metal lines is formed by etching a first metal layer. A thin dielectric layer is conformally deposited on the first metal lines. A second metal is deposited on the thin dielectric layer, filling gaps between the first metal lines. The second metal layer is planarized to form second metal lines interposed between the first metal lines, coexposing the thin dielectric layer and the second metal layer at a substantially planar surface. In some embodiments, planarization continues to remove the thin dielectric covering tops of the first metal lines, coexposing the first metal lines and the second metal lines, separated by the thin dielectric layer, at a substantially planar surface.

Forming complimentary metal features using conformal insulator layer

Different types of test structures are formed during semiconductor processing. One type of test structure comprises features that are aligned with one another and that are formed from different layers. Other types of test structures comprise features formed from respective layers that are not aligned with other test structure features. The different types of test structures are formed with a single mask that is used in a manner that also allows alignment marks to be formed which do not interfere with one another as subsequent layers are patterned. The different types of test structures can provide insight into performance characteristics of different types of devices as the semiconductor process proceeds.

Semiconductor test structures

A method of forming a three-dimensional, non-volatile memory array utilizing damascene fabrication techniques is disclosed. A bottom set of conductors is formed and a set of first pillar shaped elements of heavily doped semiconductor material as formed thereon. A mold is formed of insulating material having pillar shaped openings self-aligned with the first pillar shaped elements and a second semiconductor is deposited over the mold to form second pillar shaped elements aligned with the first pillar shaped elements. The pillar elements formed may be further processed by forming another mold of insulating material having trench openings aligned with the pillar shaped elements and then filling the trenches with conductive material to form conductors coupled to the pillar shaped elements.

A three dimensional circuit structure including tapered pillars between first and second signal lines. An apparatus including a first plurality of spaced apart coplanar conductors disposed in a first plane over a substrate; a second plurality of spaced apart coplanar conductors disposed in a second plane, the second plane parallel to and different from the first plane; and a plurality of cells disposed between one of the first conductors and one of the second conductors, wherein each of the plurality of cells have a re-entrant profile.

Patterning three dimensional structures

An apparatus including a circuit of n circuit levels formed over a substrate from a first level to a nth level, wherein n is greater than one, and each of the n circuit levels has a material parameter change that is at least in part caused by a thermal processing operation that is applied to more than one of the n circuit levels simultaneously. An apparatus including a circuit of a plurality of circuit levels, each of the plurality of circuit levels having substantially similar material parameters.

Thermal processing for three dimensional circuits

Wafers of the present invention comprise a semiconductor layer and a dielectric layer. The semiconductor layer is patterned to form semiconductor regions, and the dielectric layer is deposited on top of the semiconductor layer. Chemical mechanical planarization (CMP) is performed to remove a portion of the dielectric layer, exposing the upper surfaces of the semiconductor regions. The amount of CMP necessary to expose all of the semiconductor regions on the wafer is reduced, because the dielectric is targeted to deposit up to the upper edge of the semiconductor regions in the spaces in between the semiconductor regions. This technique reduces non-uniformities in the thickness of the dielectric and semiconductor layers across the wafer. The thickness of the dielectric or semiconductor layer deposited on polish monitor pads located at the edges of each die may be monitored to determine when enough CMP has been performed to expose each of the semiconductor regions.

Structure and method for wafer comprising dielectric and semiconductor

The invention is directed to a method of forming a three dimensional circuit including introducing a three dimensional circuit over a substrate. In one embodiment, the three dimensional circuit includes a circuit structure in a stacked configuration between a first signal line and a second signal line, where the two signal lines comprise similar materials. The method includes selectively patterning the second signal line material and the circuit without patterning the first signal line. One way the second signal line is patterned without patterning the first signal line is by modifying the etch chemistry. A second way the second signal line is patterned without patterning the first signal line is by including an etch stop between the first signal line and the second signal line. The invention is also directed at targeting a desired edge angle of a stacked circuit structure. In terms of patterning techniques, a desired edge angle is targeted by modifying, for example, the etch chemistry from one that is generally anisotropic to one that has a horizontal component to achieve an edge angle that is slightly re-entrant (i.e., having negative slope).

Postponing at least some thermal processing operations, as multiple levels of a three dimensional circuit are formed.

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Fremont, CA, United States of America

Calvin K Li