Sandisk 3d LLC

Cypress Semiconductor Corporation

Sandisk Corporation

Usha Raghuram

Michael Konevecki

Samuel Vance Dunton

S Brad Herner

Christopher John Petti

Andrew J Walker

Tanmay Kumar

Michael L Chan

Maitreyee Mahajani

Steven J Radigan

James E Nulty

Sucheta Nallamothu

Mark Harold Clark

Steven Patrick Maxwell

Chan-Lon Yang

Chuanbin Pan

Vance Dunton

Paul Wai Kie Poon

Daniel J Arnzen

Kimberley A Kaufman

Sam G Geha

Hanna Bamnolker

Yoichiro Tanaka

Tinghao Frank Wang

Prashant B Phatak

A method of making a semiconductor device includes providing an insulating layer containing a plurality of openings, forming a first semiconductor layer in the plurality of openings in the insulating layer and over the insulating layer, and removing a first portion of the first semiconductor layer, such that first conductivity type second portions of the first semiconductor layer remain in lower portions of the plurality of openings in the insulating layer, and upper portions of the plurality of openings in the insulating layer remain unfilled. The method also includes forming a second semiconductor layer in the upper portions of the plurality of openings in the insulating layer and over the insulating layer, and removing a first portion of the second semiconductor layer located over the insulating layer. The second conductivity type second portions of the second semiconductor layer remain in upper portions of the plurality of openings in the insulating layer to form a plurality of pillar shaped diodes in the plurality of openings.

Pillar devices and methods of making thereof

Methods in accordance with the invention involve patterning and etching very small dimension pillars, such as in formation of a memory array in accordance with the invention. When dimensions of pillars become very small, the photoresist pillars used to pattern them may not have sufficient mechanical strength to survive the photoresist exposure and development process. Using methods according to the present invention, these photoresist pillars are printed and developed larger than their intended final dimension, such that they have increased mechanical strength, then are shrunk to the desired dimension during a preliminary etch performed before the etch of underlying material begins.

Patterning of submicron pillars in a memory array

A method is provided for forming a monolithic three dimensional memory array. The method includes forming a first memory level above a substrate, and monolithically forming a second memory level above the first memory level. The first memory level is formed by forming first substantially parallel conductors extending in a first direction, forming first pillars above the first conductors, each first pillar including a first conductive layer or layerstack above a vertically oriented diode, the first pillars formed in a single photolithography step, depositing a first dielectric layer above the first pillars, etching first trenches in the first dielectric layer, the first trenches extending in a second direction. After etching, a lowest point in the trenches is above a lowest point of the first conductive layer or layerstack, and the first conductive layer or layerstack does not include a resistivity-switching metal oxide or nitride. Numerous other aspects are provided.

Methods for protecting patterned features during trench etch

A method for fabricating a 3-D monolithic memory device in which a via and trench are etched using an amorphous carbon hard mask. The via extends in multiple levels of the device as a multi-level vertical interconnect. The trench extends laterally, such as to provide a word line or bit line for memory cells, or to provide other routing paths. A dual damascene process can be used in which the via is formed first and the trench is formed second, or the trench is formed first and the via is formed second. The technique is particularly suitable for deep via applications, such as for via depths of greater than 1 &#x3bc;m. A dielectric antireflective coating, optionally with a bottom antireflective coating, can be used to etch an amorphous carbon layer to provide the amorphous carbon hard mask.

Dual damascene with amorphous carbon for 3D deep via/trench application

A method of making a non-volatile memory device includes providing a substrate having a substrate surface, and forming a non-volatile memory array over the substrate surface. The non-volatile memory array includes an array of semiconductor diodes, and each semiconductor diode of the array of semiconductor diodes is disposed substantially parallel to the substrate surface.

Diode array and method of making thereof

A method is described to form a nonvolatile memory cell having a contact area between a phase-change material such as a chalcogenide and a heat source which is smaller than photolithographic limits. A conductive or semiconductor pillar is exposed at a dielectric surface and recessed by selective etch. A thin, conformal layer of a spacer material is deposited on the dielectric top surface, the pillar top surface, and the sidewalls of the recess, then removed from horizontal surfaces by anistropic etch, leaving a spacer on the sidewalls defining a reduced volume within the recess. The phase change material is deposited within the spacer, having a reduced contact area to the underlying conductive or semiconductor pillar.

Method of making a nonvolatile phase change memory cell having a reduced contact area

A method of making a device includes forming a device layer, forming an organic hard mask layer over the device layer, forming a first oxide hard mask layer over the organic hard mask layer, forming a DARC layer over the first oxide hard mask layer, forming a photoresist layer over the DARC layer, patterning the photoresist layer to form a photoresist pattern, and transferring the photoresist pattern to the device layer using the DARC layer, the first oxide hard mask layer and the organic hard mask layer.

Modified DARC stack for resist patterning

A semiconductor wafer assembly includes a base of dielectric. A layer of silicon is deposited thereover. A metal hard mask is deposited over the silicon. A dielectric hard mask is deposited over the metal hard mask. Photoresist is deposited over the dielectric hard mask, whereby a plurality of sacrificial columns is formed from the layer of metal hard mask through the photoresist such that the sacrificial columns extend out from the silicon layer. An interface layer is disposed between the layer of conductive material and the layer of hard mask to enhance adhesion between each of the plurality of sacrificial columns and the layer of conductive material to optimize the formation of junction diodes out of the silicon by preventing the plurality of sacrificial columns from being detached from the layer of silicon prematurely due to the sacrificial columns peeling or falling off.

Liner for tungsten/silicon dioxide interface in memory

A substantially planar surface coexposes conductive or semiconductor features and a dielectric etch stop material. A second dielectric material, different from the dielectric etch stop material, is deposited on the substantially planar surface. A selective etch etches a hole or trench in the second dielectric material, so that the etch stops on the conductive or semiconductor feature and the dielectric etch stop material. In a preferred embodiment the substantially planar surface is formed by filling gaps between the conductive or semiconductor features with a first dielectric such as oxide, recessing the oxide, filling with a second dielectric such as nitride, then planarizing to coexpose the nitride and the conductive or semiconductor features.

Method for reducing dielectric overetch using a dielectric etch stop at a planar surface

A method of plasma etching transition metal oxide thin films using carbon monoxide as the primary source gas. This permits carbonyl chemistries to be used at ambient temperature, without heating.

Method of plasma etching transition metal oxides

The invention provides for polysilicon vias connecting conductive polysilicon layers formed at different heights. Polysilicon vias are advantageously used in a monolithic three dimensional memory array of charge storage transistors. Polysilicon vias according to the present invention can be used, for example, to connect the channel layer of a first device level of charge storage transistor memory cells to the channel layer of a second device layer of such cells formed above the first device level. Similarly, vias according to the present invention can be used to connect the wordline of a first device level of charge storage transistor memory cells to the channel layer of a second device layer of such cells.

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San Jose, CA, United States of America

Usha Raghuram