U.S. patent application number 13/224268 was filed with the patent office on 2013-03-07 for method, system, and device for l-shaped memory component.
This patent application is currently assigned to Micron Technology, Inc.. The applicant listed for this patent is Fabio Pellizer, Innocenzo Tortorelli. Invention is credited to Fabio Pellizer, Innocenzo Tortorelli.
Application Number | 20130058158 13/224268 |
Document ID | / |
Family ID | 47753096 |
Filed Date | 2013-03-07 |
United States Patent
Application |
20130058158 |
Kind Code |
A1 |
Pellizer; Fabio ; et
al. |
March 7, 2013 |
METHOD, SYSTEM, AND DEVICE FOR L-SHAPED MEMORY COMPONENT
Abstract
Embodiments disclosed herein may relate to forming reduced size
storage components in a cross-point memory array. In an embodiment,
a storage cell comprising an L-shaped storage component having an
approximately vertical portion extending from a first electrode
positioned below the storage material to a second electrode
positioned above and/or on the storage component. A storage cell
may further comprise a selector material positioned above and/or on
the second electrode and a third electrode positioned above and/or
on the selector material, wherein the approximately vertical
portion of the L-shaped storage component comprises a reduced size
storage component in a first dimension.
Inventors: |
Pellizer; Fabio; (Cornate
D'Adda, IT) ; Tortorelli; Innocenzo; (Moncalieri,
IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Pellizer; Fabio
Tortorelli; Innocenzo |
Cornate D'Adda
Moncalieri |
|
IT
IT |
|
|
Assignee: |
Micron Technology, Inc.
Boise
ID
|
Family ID: |
47753096 |
Appl. No.: |
13/224268 |
Filed: |
September 1, 2011 |
Current U.S.
Class: |
365/163 ; 257/4;
257/E21.004; 257/E45.001; 438/382 |
Current CPC
Class: |
H01L 45/06 20130101;
H01L 27/2463 20130101; H01L 27/2427 20130101; H01L 45/124 20130101;
H01L 45/1691 20130101 |
Class at
Publication: |
365/163 ;
438/382; 257/4; 257/E21.004; 257/E45.001 |
International
Class: |
G11C 11/00 20060101
G11C011/00; H01L 45/00 20060101 H01L045/00; H01L 21/8239 20060101
H01L021/8239 |
Claims
1. A method, comprising: forming a size of a first dimension and a
second dimension of one or more storage components for a first
trench and a second trench; the first trench positioned along a
first direction in a dielectric material and the second trench
positioned along a second direction in the dielectric material
approximately orthogonal to the first direction; wherein the size
of the first dimension is partially and/or substantially formed by
deposition of storage component material over and/or on the
dielectric material and the size of the second dimension is
partially and/or substantially formed by a lithographic
operation.
2. The method of claim 1, wherein the depositing the storage
component material comprises depositing phase change material over
and/or on the dielectric material.
3. The method of claim 2, wherein the phase change material
comprises a chalcogenide glass material.
4. The method of claim 1, wherein the depositing the storage
component material over and/or on the dielectric material comprises
depositing the storage component material over and/or on a nitride
material.
5. The method of claim 1, wherein the depositing the storage
component material over and/or on the dielectric material comprises
depositing the storage component material on one or more
approximately vertical walls of one or more of the first and second
trenches.
6. The method of claim 5, wherein the one or more storage
components comprise a memory array; and further comprising:
depositing an additional dielectric material over and/or on the
memory array, including filling the one or more of the first and
second trenches.
7. The method of claim 6, wherein the depositing the additional
dielectric material over and/or on the memory array comprises
depositing an oxide material over and/or on the memory array,
including filling the one or more of the first and second
trenches.
8. The method of claim 5, further comprising planarizing a top
surface of the memory array to remove a portion of the additional
dielectric material and portions of the storage component material
not located within the one or more of the first and second
trenches, and to expose one or more top edges of approximately
vertical portions of storage component material deposited on the
one or more approximately vertical walls of the one or more
trenches.
9. The method of claim 8, further comprising: depositing an
electrode material over and/or on the planarized surface of the
memory array; depositing a selector material over and/or on the
electrode material; and depositing an additional selector material
over and/or on the selector material.
10. The method of claim 9, further comprising etching one or more
additional trenches positioned approximately along the first
direction to at least partially isolate individual storage
components of the memory array.
11. The method of claim 9, wherein the etching the one or more
additional trenches positioned approximately along the first
direction comprises etching the one or more additional trenches
positioned approximately along the first direction through the
electrode material, the selector material, the additional electrode
material, the dielectric material within the one or more trenches,
and through a bottom electrode material.
12. The method of claim 11, further comprising filling the memory
array with additional dielectric material and planarizing the top
surface of the memory array to expose the additional electrode
material deposited on the selector material.
13. The method of claim 1, wherein the forming the one or more
additional trenches positioned approximately along the direction
approximately orthogonal to the first direction in the one or more
materials of the memory array comprises etching one or more
sections of the one or more materials of the memory array utilizing
a reduced pitch mask.
14. A memory device, comprising: a storage cell comprising an
L-shaped storage component having an approximately vertical portion
extending from a first electrode positioned below the storage
material to a second electrode positioned above and/or on the
storage component, the storage cell further comprising a selector
material positioned above and/or on the second electrode and a
third electrode positioned above and/or on the selector material,
wherein the approximately vertical portion of the L-shaped storage
component comprises a reduced size storage component in a first
dimension.
15. The memory device of claim 14, wherein the storage cells
comprises a phase change memory with selector (PCMS) storage
cell.
16. The memory device of claim 15, wherein the storage cell further
comprises an integrated self-heating structure.
17. The memory device of claim 13, wherein the reduced size of the
storage component in the first dimension is partially and/or
substantially affected by a deposition of storage component
material on an approximately vertical wall of a trench located in a
dielectric material.
18. The memory device of claim 17, wherein the reduced size of the
storage component in the first dimension is partially and/or
substantially affected by a thickness of the storage component
material deposition.
19. The memory device of claim 18, wherein a size of the storage
component in a second dimension is partially and/or substantially
affected by an additional trench.
20. The apparatus of claim 19, wherein the additional trench is
positioned in a direction approximately orthogonal to the trench
located in the dielectric material.
21. A method, comprising: receiving one or more signals indicative
of a memory access command from a processor of a computing
platform; and accessing a phase change memory with selector (PCMS)
array of "L" shaped storage components in response to receiving the
memory access command, wherein the accessing includes changing a
state of one or more of the "L" shaped storage components of the
PCMS array, wherein the one or more of the PCMS array of the "L"
shaped storage components individually comprise an L-shaped storage
material having an approximately vertical portion extending from a
first electrode positioned below the storage component material to
a second electrode positioned above and/or on the storage component
material, the array of storage components further individually
comprising a selector material positioned above and/or on the
second electrode and a third electrode positioned above and/or on
the selector material, wherein the approximately vertical portions
of the L-shaped storage material of the individual storage
components comprise a reduced size storage component in a first
dimension.
22. The method of claim 21, wherein the size of the storage
component in the first dimension is partially and/or substantially
affected by a deposition of storage component material to one or
more approximately vertical walls of one or more trenches located
in a dielectric material.
23. The method of claim 22, wherein the size of the storage
component in a second dimension is partially and/or substantially
affected by one or more additional trenches formed in one or more
materials of the array of storage components.
24. The method of claim 23, wherein the one or more additional
trenches are positioned along a direction approximately orthogonal
to the one or more trenches located in the dielectric material.
Description
BACKGROUND
[0001] 1. Field
[0002] Subject matter disclosed herein may relate to integrated
circuit devices, and may relate, more particularly, to circuitry
related to a memory array.
[0003] 2. Information
[0004] Integrated circuit devices, such as memory devices, for
example, may be found in a wide range of electronic devices. For
example, memory devices may be used in computers, digital cameras,
cellular telephones, personal digital assistants, etc. Factors
related to a memory device that may be of interest to a system
designer in considering a memory device's suitability for any
particular application may include, physical size, storage density,
operating voltages, granularity of read/write operations,
throughput, transmission rate, and/or power consumption, for
example. Other example factors that may be of interest to system
designers include cost of manufacture, and/or ease of
manufacture.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Claimed subject matter is particularly pointed out and
distinctly claimed in the concluding portion of the specification.
However, both as to organization and/or method of operation,
together with objects, features, and/or advantages thereof, it may
best be understood by reference to the following detailed
description if read with the accompanying drawings in which:
[0006] FIG. 1 is an illustration depicting a cross-sectional view
of a phase change memory with a selector (PCMS) device, according
to an embodiment.
[0007] FIG. 2 is an illustration depicting a top view of a portion
of a memory device, according to an embodiment.
[0008] FIG. 3a is an illustration depicting a cross-sectional view
of a portion of an example technique for forming storage components
in a cross-point memory array, according to an embodiment.
[0009] FIG. 3b is an illustration depicting a cross-sectional view
of an additional portion of an example technique for forming
storage components in a cross-point memory array, according to an
embodiment.
[0010] FIG. 3c is an illustration depicting a cross-sectional view
of a subsequent processing step of a portion of an example
technique for forming storage components in a cross-point memory
array, according to an embodiment.
[0011] FIG. 3d is an illustration depicting a cross-sectional view
of a subsequent processing step of a portion of an example
technique for forming storage components in a cross-point memory
array, according to an, embodiment.
[0012] FIG. 3e is an illustration depicting a cross-sectional view
of a subsequent processing step of a portion of an example
technique for forming storage components in a cross-point memory
array, according to an embodiment.
[0013] FIG. 3f is an illustration depicting a cross-sectional view
of a subsequent processing step of a portion of an example
technique for forming storage components in a cross-point memory
array, according to an embodiment.
[0014] FIG. 3g is an illustration depicting a cross-sectional view
of a subsequent processing step of a portion of an example
technique for forming storage components in a cross-point memory
array, according to an embodiment.
[0015] FIG. 3h is an illustration depicting a cross-sectional view
of a subsequent processing step of a portion of an example
technique for forming storage components in a cross-point memory
array, according to an embodiment.
[0016] FIG. 3i is an illustration depicting a cross-sectional view
of a subsequent processing step of a portion of an example
technique for forming storage components in a cross-point memory
array, according to an embodiment.
[0017] FIG. 3j is an illustration depicting a cross-sectional view
of a subsequent processing step of a portion of an example
technique for forming storage components in a cross-point memory
array, according to an embodiment.
[0018] FIG. 3k is an illustration depicting a cross-sectional view
of a subsequent processing step of a portion of an example
technique for forming storage components in a cross-point memory
array, according to an embodiment.
[0019] FIG. 4 is a schematic block diagram depicting a system,
including a cross-point array memory device, according to an
embodiment.
[0020] Reference is made in the following detailed description to
the accompanying drawings, which form a part hereof, wherein like
numerals may designate like parts throughout to indicate
corresponding and/or analogous elements. It will be appreciated
that elements illustrated in the figures have not necessarily been
drawn to scale, such as for simplicity and/or clarity of
illustration. For example, dimensions of some elements may be
exaggerated relative to other elements for clarity. Further, it is
to be understood that other embodiments may be utilized.
Furthermore, structural and/or logical changes may be made without
departing from the scope of claimed subject matter. It should also
be noted that directions and/or references, for example, up, down,
top, bottom, and so on, may be used to facilitate discussion of
drawings and/or are not intended to restrict application of claimed
subject matter. Therefore, the following detailed description is
not to be taken to limit the scope of claimed subject matter and/or
equivalents.
DETAILED DESCRIPTION
[0021] Integrated circuit devices, such as non-volatile memory
devices, may be found in a wide range of electronic devices.
Non-volatile memory devices may be used in computers, digital
cameras, cellular telephones, and/or personal digital assistants,
to name but a few examples. Factors related to a memory device that
may be of interest in considering a memory device's suitability for
a particular application may include physical size, storage
density, operating voltages, granularity of read/write operations,
throughput, transmission rate, and/or power consumption. Other
example factors that may be of interest may include cost of
manufacture, and/or ease of manufacture. One example aspect of
memory array design that may affect one or more factors may include
integrated circuit die size. One or more process technologies
utilized to manufacture a memory device may at least in part
determine at least some of the factors, such as those mentioned
above, including storage density, physical size, and/or cost/ease
of manufacture, for example.
[0022] An example process for forming one or more storage
components in a phase change with selector (PCMS) memory array may
comprise depositing a storage component material over and/or on an
insulation layer having one or more trenches formed therein to
affect a first dimension of one or more storage components. An
example process may further comprise forming one or more trenches
in one or more materials of the memory array to affect a second
dimension of the storage components at least in part through a
lithographic operation utilizing a reduced pitch mask. In an
embodiment, for example, relatively high density storage arrays may
be accomplished while reducing programming current.
[0023] In an example embodiment, individual storage components may
comprise an "L" shape, wherein an approximately vertical portion of
an "L" shape comprises an aspect ratio at least partially affected
by a thickness of a deposition of storage component material on an
approximately vertical wall of a trench in one dimension and by an
additional trench formed in an approximately orthogonal direction
using a reduced pitch photolithographic mask in another dimension.
A reduced aspect ratio, for example, may allow for a reduction in
programming current. Also in an example embodiment, a horizontal
portion of the "L" shaped storage component, hereafter called lower
leg of an "L" shape, for an individual storage component may
contact an electrode positioned between a storage component and a
selector. A lower leg of an "L" shaped storage component may
provide increased contact area with an electrode, providing an
improved electrical connection with reduced resistance and further
help increase yield during manufacturing. In one or more example
embodiments, an increased contact area between a storage component
and an electrode may be provided while still providing a reduced
aspect ratio storage component. In this manner, reduced programming
current may be achieved and improved manufacturing yield may also
be achieved. However, claimed subject matter is not limited in
scope in these respects.
[0024] FIG. 1 is an illustration depicting a cross-sectional view
of an example embodiment 100 of a memory array. In an embodiment,
memory array 100 may comprise a phase change memory switch (PCMS)
array. A PCMS device may also be referred to as a "phase change
memory with selector" device. For an embodiment, a phase change
memory switch device, such as PCMS 100, may be implemented as a
cross-point memory array. In an embodiment of a PCMS cross-point
array, a plurality of approximately orthogonally directed
electrically conductive lines, referred to as "electrodes", may be
formed, with one subset of orthogonally directed electrodes in a
material positioned below an array of storage components and
another subset of orthogonally directed electrodes in a material
positioned above the array of storage components. As used herein,
the term "cross-point memory array" refers to a memory array having
two or more approximately orthogonally directed sets of electrodes.
For example, as depicted in FIG. 1, an example embodiment of a
cross-point memory array may comprise one set of electrodes, such
as electrodes depicted in electrode material 110, positioned along
a direction approximately orthogonal to a direction of another set
of electrodes, such as electrodes depicted in electrode material
140.
[0025] An electrically conductive component, such as an
"electrode", refers to component that may be utilized to route
signals and/or supply voltages within a metal material and/or
within a memory array. An electrically conductive component, such
as an electrode, may comprise a sufficiently electrically
conductive material, such as polysilicon, carbon, and/or metallic
material, such as tungsten, titanium nitride, and/or titanium
aluminum nitride, for example, for use in a memory device. Of
course, claimed subject matter is not limited in scope in these
respects. Other materials may, of course, also be used in an
embodiment.
[0026] In an embodiment, an electrode material, such as electrode
material 140, may be formed above one or more materials, such as
material 150, comprising one or more semiconductor materials and/or
one or more metal materials. An electrode material, such as
electrode material 110, may be positioned above a selector
material, such as material 120, and/or a storage component
material, such as material 130, in an embodiment. Semiconductor and
metal material 150 may, for example, comprise one or more decoder
circuits, such as one or more data/sense lines, for example a
bit-line, decoder circuits and/or one or more access lines, for
example a word-line, decoder circuits, in an embodiment.
Semiconductor and metal material 150 may further comprise, in an
embodiment, one or more metal materials comprising electrodes
utilized to route signals and/or supply voltages to electrode
material 140 and/or electrode material 110, in an embodiment. For
example, semiconductor and metal material 150 may comprise
electrically conductive interconnect that may electrically couple a
decoder circuit to an electrode in electrode material 140, although
claimed subject matter is not limited in this respect.
[0027] In an embodiment, electrically conductive electrodes of
electrode material 140 may lie along a direction approximately
orthogonal to a direction of electrically conductive electrodes of
electrode material 110. Also, in an embodiment, a storage component
material 130, and/or a selector material, such as selector material
120, may be formed and/or positioned between two or more electrode
materials, such as electrode material 140 and/or electrode material
110, in an embodiment.
[0028] Also, in an example embodiment, one or more decks of memory
may be formed. For example, memory device 100 may comprise a
one-deck memory array. Other embodiments may comprise a greater
amount of decks. For example, other embodiments may comprise four
decks, although claimed subject matter is not limited in this
respect. As used herein, a "deck" of memory may comprise an array
of memory cells and a plurality of electrodes. For example, a first
deck may comprise a plurality of access line, for example
word-line, electrodes, an array of storage components formed over
and/or on a plurality of word-line electrodes, and a plurality of
bit-line electrodes formed over and/or on a plurality of storage
components, for example. A second deck may comprise a plurality of
bit-line electrodes shared with a first deck and may further
comprise an additional array of storage components positioned over
and/or on a plurality of bit-line electrodes, according to an
embodiment. Also, for a second deck, an additional plurality of
word-line electrodes may be formed over and/or on an additional
array of storage components. Of course, claimed subject matter is
not limited in scope in these respects.
[0029] For a memory array, such as PCMS array 100, a storage
component may comprise a chalcogenide glass material, in an
embodiment. A PCMS storage component may be configured to retain or
store memory in at least two different selectable states. For
example in a binary system, the states are considered either a "0"
or a "1,", where a "set" state, representing a binary value of `1`,
for example, may correspond to a more crystalline , more conductive
state for a material of a storage component and a "reset" state,
representing a binary value of `0`, for example, corresponding to a
more amorphous, more resistive state of a storage component
material. In other systems, at least some individual memory cells
may be configured to store more than two levels or states of
information. In a PCMS memory array, heat sufficient to change a
phase of a storage component may be achieved by application of a
current and/or voltage pulse to the storage component, in an
embodiment. Further, in one or more example embodiments,
cross-point memory arrays may comprise one or more technologies
other than PCMS, such as resistive memory technologies and/or other
types of memory, and claimed subject matter is not limited in scope
in this respect.
[0030] FIG. 2 is an illustration depicting a top view of a portion
of example PCMS cross-point memory array 100. Depicted in FIG. 2 is
an electrode material 110 comprising a plurality of electrically
conductive electrodes laying in a direction and an electrode
material 140 comprising a plurality of electrically conductive
electrodes laying in a direction approximately orthogonal to the
direction of electrode material 110. FIG. 2 additionally shows
cross-sectional line segments `A`, and `B` that correspond to cross
sectional views A and B. In an embodiment, a storage component 105
of PCMS array 100, located between electrode materials 110 and/or
140, may be selected and/or accessed in part by energizing
appropriate electrodes in electrode material 140 and/or electrode
material 110. For an example, PCMS cross-point memory array, such
as array 100, one or more driver circuits, such as one or more
word-line driver circuits and/or one or more bit-line driver
circuits, may transmit one or more signals, such as one or more
word-line select signals and/or one or more bit-line select
signals, to one or more electrodes of electrode material 110 and/or
electrode material 140. In an embodiment, electrode material 140
may comprise a plurality of word-line electrodes, for example.
Also, in an embodiment, electrode material 110 may comprise a
plurality of bit-line electrodes, although claimed subject matter
is not limited in these respects. By transmitting a word-line
select signal to a word-line electrode of electrode material 140
and/or by transmitting a bit-select signal to a bit-line electrode
of electrode material 110 a particular storage component within
array 100 may be selected, for example.
[0031] In one or more embodiments, it may be advantageous to
provide higher density storage arrays, for example, while also
providing reduced storage component programming current. It may
further be advantageous to provide higher density storage arrays
and/or reduced storage component programming current without
significantly increasing cost and/or difficulty of manufacture, for
example. Of course, claimed subject matter is not limited in these
respects. These are merely non-limiting examples.
[0032] As mentioned previously, an example process for forming one
or more storage components in a phase change with selector (PCMS)
memory array may comprise depositing storage component material
over and/or on one or more trenches in a dielectric material to
decrease die size. One or more trenches may be formed in an area
above a plurality of rows individually comprising an electrode and
a selector such that bottom portions a storage component may
contact an electrode positioned between a storage component and a
selector, in an embodiment. An example process may further comprise
forming a trench in a material of the memory array to affect a size
of the storage components at least in part through a lithographic
operation utilizing a reduced pitch mask. Individual storage
components may comprise an "L" shape, wherein an approximately
vertical portion of an "L" shape comprises an aspect ratio at least
partially affected by a thickness of a deposition of storage
component material on an approximately vertical wall of a trench in
one dimension and by an additional trench formed in an
approximately orthogonal direction using a reduced pitch
photolithographic mask in another dimension. A reduced aspect
ratio, for example, may allow for a reduction in programming
current. Also in an example embodiment, a horizontal potion of the
"L" shaped storage component, hereafter called lower leg of an "L"
shape, for an individual storage component may contact an electrode
positioned between a storage component and a selector. A lower leg
of an "L" shaped storage component may provide increased contact
area with an electrode, providing an improved electrical connection
with reduced resistance and further help increase yield during
manufacturing. In one or more example embodiments, an increased
contact area between a storage component and an electrode may be
provided while still providing a reduced aspect ratio storage
component. However, claimed subject matter is not limited in scope
in these respects.
[0033] FIGS. 3a through 3k illustrate a process of forming PCMS 100
in accordance with an embodiment of the present technology.
Referring to FIG. 3a, Cross Section A depicts a cross-sectional
view of a portion of PCMS array 100 looking in an `x` direction,
and Cross Section B depicts a cross-sectional view of a portion of
PCMS array 100 looking in a `y` direction that is approximately
orthogonal to an `x` direction. FIGS. 3a through 3k depict an
example technique for forming at least some aspects of PCMS array
100. Of course, claimed subject matter is not limited in scope to
the particular examples described herein and as depicted in FIGS.
3a through 3k.
[0034] As illustrated in FIG. 3a, As illustrated in FIG. 3a, a
dielectric material 302, such as a nitride, may be formed by
deposition and/or other known processes over and/or on a
semiconductor and metal material 150, in an embodiment. Also in an
embodiment, a material, such as tungsten, may be deposited or
otherwise formed by known methods over and/or on a dielectric, such
as a nitride, to produce an electrode material 140. Electrode
material 140 may further comprise, for example, platinum, carbon,
titanium nitride, and/or titanium aluminum nitride, among others,
in an embodiment. Dielectric material 302 may comprise, for
example, silicon nitride and/or silicon oxynitride, in an
embodiment. Embodiments are not limited to a particular type of
dielectric material or electrode material. Note that at this point
in an example process, electrode material 140 may comprise a
deposited sheet of material, and so may not yet comprise individual
electrodes. In an implementation, electrode material 140 may
eventually comprise one or more electrodes approximately in
parallel and approximately along an `x` direction. Also, in an
embodiment, an additional dielectric material 306 may be formed by
deposition and/or other known processes over and/or on electrode
material 140, for example. Dielectric material 306 may comprise,
for example, silicon nitride and/or silicon oxynitride, in an
embodiment.
[0035] FIG. 3b shows a subsequent stage of the process following
the process described in FIG. 3a. As illustrated in FIG. 3b, a
trench 301 may be formed by etching and/or other known processes in
a dielectric material 306, for example. In an embodiment, an
etching process may stop approximately at electrode material 140,
for example. In an embodiment, a photoresist etch mask may be
formed utilizing a lithographic technique, for example, to
substantially protect PCMS array 100 outside of an area designated
for trench 301 during an etching process, although the scope of
claimed subject matter is not limited in this respect. A storage
component material 340 may be formed by deposition and/or other
known processes over and/or on a surface of PCMS array 100,
including within trench 301. In an embodiment, storage component
material 340 may be deposited in a conformal manner. In an
embodiment, storage component material 340 may comprise a
chalcogenide glass material, for example. An additional dielectric
material 307 may be formed by deposition and/or other known
processes over and/or on storage component material 340, in an
embodiment. Dielectric material 307 may comprise, for example,
silicon nitride and/or silicon oxynitride, in an embodiment. Again,
other materials are also possible in other embodiments.
[0036] FIG. 3c shows a subsequent stage of the process following
the process described in FIG. 3b. As illustrated in FIG. 3c, a
dielectric material 308, such as an oxide, may be formed by
deposition and/or other known processes over and/or on PCMS array
100, including filling trench 301. In an embodiment, dielectric
material 308 may comprise silicon oxide, for example.
[0037] FIG. 3d shows a subsequent stage of the process following
the process described in FIG. 3c. As illustrated in FIG. 3d, PCMS
array 100 may be substantially planarized to remove portions of
dielectric material 308 not within trench 301 and/or storage
component material 340 not within trench 301. Planarization, in an
embodiment, may further expose portions of storage component
material 340 at a top surface of PCMS 100. Also, in an embodiment,
an example planarization process may comprise a chemical/mechanical
polish (CMP) technique, although claimed subject matter is not
limited in scope in this respect. As used herein, the term "wall"
as it relates to a trench refers to an approximately vertical
boundary of a trench formed, for example, by an etching
process.
[0038] FIG. 3e shows a subsequent stage of the process following
the process described in FIG. 3d. As depicted in FIG. 3e, an
electrode material, such as middle electrode 360, may be formed by
deposition and/or other known processes over and/or on PCMS array
100. In an embodiment, middle electrode 360 may comprise carbon,
titanium nitride, and/or titanium aluminum nitride, for example,
although claimed subject matter is not limited in this respect.
Additionally, a selector material 120 may be formed by deposition
and/or other known processes over and/or on middle electrode 360.
In an embodiment, selector material 120 may comprise a chalcogenide
glass material. However, in an embodiment, selector material 120
may comprise a different chalcogenide material than that utilized
for storage component material 340.
[0039] FIG. 3f shows a subsequent stage of the process following
the process described in FIG. 3e. FIG. 3f illustrates a plurality
of trenches, such as trenches 303, formed by etching and/or other
known processes in PCMS array 100 to provide a plurality of rows
along a `y` direction. In an embodiment, an example etching process
may etch upper electrode 370, selector material 120, and/or middle
electrode 360, as illustrated by trenches 303 in FIG. 3f. An
example etching process may further etch dielectric material 308
previously deposited in trench 301 and/or a portion of an
approximately horizontal section of storage component material 340
previously positioned at a bottom of trench 301, as also
illustrated by trenches 303. Additionally, in an embodiment, an
example etching process may etch through sections of dielectric
material 306 and further may partially etch sections of dielectric
material 302, as additionally illustrated by trenches 303.
[0040] During etching, in an example embodiment, components of
storage component material 340 located within filled trench 301 may
be partially and/or substantially protected by portions of
dielectric material 308 and/or by portions of dielectric material
307 located within filled trench 301, except for portions of
storage component material 340 at the bottom of trench 301. An
example etching process may form a plurality of individual
electrodes in electrode material 140, in an embodiment. In an
embodiment, a plurality of electrodes of electrode material 140 may
comprise a plurality of word-line electrodes for PCMS array 100,
although claimed subject matter is not limited in this respect.
[0041] An example etching process may further partially and/or
substantially result in forming storage components 305, in an
embodiment. Storage components 305 may, in an example embodiment,
comprise an "L"-shaped storage component. In an embodiment, storage
components 305 may be formed in one dimension in accordance with a
deposition of storage component material over and/or on
approximately vertical walls of a trench, such as trench 301. In an
embodiment, a width of a storage component in a dimension formed by
deposition of storage component material may comprise a width that
is smaller than would otherwise be available through conventional
lithographic techniques. In this manner, a reduced-size storage
component relative to standard pitch, for example, for a PCMS
array, such as PCMS array 100, may be realized.
[0042] FIG. 3g shows a subsequent stage of the process following
the process described in FIG. 3f. As illustrated in FIG. 3g,
trenches 303 may be filled by deposition of additional dielectric
material, such as nitride 320, to provide some additional stability
and/or electrical isolation, for example. Nitride 306 may comprise,
for example, silicon nitride and/or silicon oxynitride, in an
embodiment, although claimed subject matter is not limited in scope
in this respect.
[0043] FIG. 3h shows a subsequent stage of the process following
the process described in FIG. 3g. As depicted in FIG. 3h,
dielectric material, such as nitride 320, may be planarized until
upper electrode 370 is substantially exposed. Also, in an
embodiment, an example planarization process may comprise a CMP
technique, although claimed subject matter is not limited in scope
in this respect.
[0044] FIG. 3i shows a subsequent stage of the process following
the process described in FIG. 3h. As illustrated at FIG. 3i, a
metallic material, such as tungsten, may be formed by deposition
and/or other known processes over and/or on PCMS array 100 to form
electrode material 110. Electrode material 110 may further
comprise, for example, platinum, carbon, titanium nitride, and/or
titanium aluminum nitride, among others, in an embodiment.
[0045] FIG. 3j shows a subsequent stage of the process following
the process described in FIG. 3i. As depicted in FIG. 3j, a
plurality of trenches 313 may be formed by etching and/or other
known processes into PCMS array 100. In an embodiment, trenches 313
may be positioned along a direction approximately orthogonal to
trenches 303. In an embodiment, an example etching process may etch
sections of electrode material 110, upper electrode 370, selector
material 120, middle electrode 360, and/or dielectric material 306.
Also, an example etching process in accordance with an embodiment
may etch electrode material 140, at least partially. In an example
embodiment, an anisotropic etch may be used.
[0046] In an embodiment, an etching process may be accomplished
utilizing a photolithographic operation. During the etch process,
portions of PCMS array 100 not intended to be etched may be
protected by a mask. Additionally, it may be noted that trenches,
such as trenches 313, may define an additional dimension of an
aspect ratio, also referred to as a cross-section, of approximately
vertical portions of one or more storage components, such as
storage components 305. In this manner, one dimension of an aspect
ratio, or cross section, of approximately vertical portions of
storage components 305 may be at least partially affected by a
thickness of a deposition of storage component material on a wall
of trench 301, and another dimension of an aspect ratio, or
cross-section, of approximately vertical portions of storage
components 305 may at least partially be affected by an example
etching process utilizing a lithographic operation. However,
claimed subject matter is not limited in scope in these
respects.
[0047] FIG. 3k shows a subsequent stage of the process following
the process described in FIG. 3j. As illustrated in FIG. 3k,
additional dielectric material, such as nitride 320, may be
deposited over and/or on PCMS 100 and within trenches 313 to
encapsulate storage components 305, in an embodiment, for example.
Deposition of additional dielectric material 320 may provide
structural stability, as well as electrical isolation for
individual aspects of PCMS array 100. However, claimed subject
matter is not limited in scope in these respects.
[0048] FIG. 4 is a schematic block diagram depicting an example
system 400 including an example PCMS 420. In an embodiment, PCMS
420 may comprise a storage area 422 including a PCMS cross-point
memory array, such as in accordance with one or more of examples.
PCMS 420 may, in an example embodiment, be coupled to a processor
410 by way of an interconnect 415.
[0049] PCMS 420 in an embodiment may comprise a control unit 426.
Additionally, storage area 422 may store instructions 424 that may
include one or more applications that may be executed by processor
410, according with an embodiment. Processor 410 may transmit a
memory access command to PCMS 420, for example. Control unit 426
may access one or more memory cells of storage area 422 at least in
part in response to receiving the memory access command from
processor 410, according to an embodiment. Of course, computing
platform 400 is merely one example of a system implemented in
accordance with claimed subject matter, and the scope of claimed
subject matter is not limited in these respects.
[0050] The term "computing platform" as used herein refers to a
system and/or a device that includes the ability to process and/or
store data in the form of signals or states. Thus, a computing
platform, in this context, may comprise hardware, software,
firmware or any combination thereof (other than software per se).
Computing platform 400, as depicted in FIG. 4, is merely one such
example, and the scope of claimed subject matter is not limited in
these respects. For one or more embodiments, a computing platform
may comprise any of a wide range of digital electronic devices,
including, but not limited to, personal desktop or notebook
computers, high-definition televisions, digital versatile disc
(DVD) players or recorders, game consoles, satellite television
receivers, cellular telephones, personal digital assistants, mobile
audio or video playback or recording devices, or any combination of
the above. Further, unless specifically stated otherwise, a process
as described herein, with reference to flow diagrams or otherwise,
may also be executed and/or controlled, in whole or in part, by a
computing platform.
[0051] The terms, "and", "or", and "and/or" as used herein may
include a variety of meanings that also are expected to depend at
least in part upon the context in which such terms are used.
Typically, "or" if used to associate a list, such as A, B or C, is
intended to mean A, B, and C, here used in the inclusive sense, as
well as A, B or C, here used in the exclusive sense. In addition,
the term "one or more" as used herein may be used to describe any
feature, structure, or characteristic in the singular or may be
used to describe a plurality or some other combination of features,
structures or characteristics. Though, it should be noted that this
is merely an illustrative example and claimed subject matter is not
limited to this example.
[0052] Methodologies described herein may be implemented by various
techniques depending, at least in part, on applications according
to particular features or examples. For example, methodologies may
be implemented in hardware, firmware, or combinations thereof,
along with software (other than software per se). In a hardware
embodiment, for example, a processing unit may be implemented
within one or more application specific integrated circuits
(ASICs), digital signal processors (DSPs), digital signal
processing devices (DSPDs), programmable logic devices (PLDs),
field programmable gate arrays (FPGAs), processors, controllers,
micro-controllers, microprocessors, electronic devices, other
devices units designed to perform the functions described herein,
or combinations thereof.
[0053] In the preceding detailed description, numerous specific
details have been set forth to provide a thorough understanding of
claimed subject matter. However, it will be understood by those
skilled in the art that claimed subject matter may be practiced
without these specific details. In other instances, methods and/or
apparatuses that would be known by one of ordinary skill have not
been described in detail so as not to obscure claimed subject
matter.
[0054] Some portions of the preceding detailed description have
been presented in terms of logic, algorithms and/or symbolic
representations of operations on binary states stored within a
memory of a specific apparatus or special purpose computing device
or platform. In the context of this particular specification, the
term specific apparatus or the like includes a general purpose
computer once it is programmed to perform particular functions
pursuant to instructions from program software. Algorithmic
descriptions and/or symbolic representations are examples of
techniques used by those of ordinary skill in the signal processing
and/or related arts to convey the substance of their work to others
skilled in the art. An algorithm is here, and generally, is
considered to be a self-consistent sequence of operations and/or
similar signal processing leading to a desired result. In this
context, operations and/or processing involve physical manipulation
of physical quantities. Typically, although not necessarily, such
quantities may take the form of electrical and/or magnetic signals
capable of being stored, transferred, combined, compared or
otherwise manipulated as electronic signals representing
information. It has proven convenient at times, principally for
reasons of common usage, to refer to such signals as bits, data,
values, elements, symbols, characters, terms, numbers, numerals,
information, or the like. It should be understood, however, that
all of these or similar terms are to be associated with appropriate
physical quantities and are merely convenient labels. Unless
specifically stated otherwise, as apparent from the following
discussion, it is appreciated that throughout this specification
discussions utilizing terms such as "processing," "computing,"
"calculating," "determining", "establishing", "obtaining",
"identifying", "selecting", "generating", or the like may refer to
actions and/or processes of a specific apparatus, such as a special
purpose computer or a similar special purpose electronic computing
device. In the context of this specification, therefore, a special
purpose computer and/or a similar special purpose electronic
computing device is capable of manipulating and/or transforming
signals, typically represented as physical electronic and/or
magnetic quantities within memories, registers, and/or other
information storage devices, transmission devices, or display
devices of the special purpose computer and/or similar special
purpose electronic computing device. In the context of this
particular patent application, the term "specific apparatus" may
include a general purpose computer once it is programmed to perform
particular functions pursuant to instructions from program
software.
[0055] In some circumstances, operation of a memory device, such as
a change in state from a binary one to a binary zero or vice-versa,
for example, may comprise a transformation, such as a physical
transformation. With particular types of memory devices, such a
physical transformation may comprise a physical transformation of
an article to a different state or thing. For example, but without
limitation, for some types of memory devices, a change in state may
involve an accumulation and/or storage of charge or a release of
stored charge. Likewise, in other memory devices, a change of state
may comprise a physical change and/or transformation in magnetic
orientation or a physical change and/or transformation in molecular
structure, such as from crystalline to amorphous or vice-versa. In
still other memory devices, a change in physical state may involve
quantum mechanical phenomena, such as, superposition, entanglement,
or the like, which may involve quantum bits (qubits), for example.
The foregoing is not intended to be an exhaustive list of all
examples in which a change in state for a binary one to a binary
zero or vice-versa in a memory device may comprise a
transformation, such as a physical transformation. Rather, the
foregoing are intended as illustrative examples.
[0056] A computer-readable (storage) medium typically may be
non-transitory and/or comprise a non-transitory device. In this
context, a non-transitory storage medium may include a device that
is tangible, meaning that the device has a concrete physical form,
although the device may change its physical state. Thus, for
example, non-transitory refers to a device remaining tangible
despite this change in state.
[0057] While there has been illustrated and/or described what are
presently considered to be example features, it will be understood
by those skilled in the art that various other modifications may be
made, and/or equivalents may be substituted, without departing from
claimed subject matter. Additionally, many modifications may be
made to adapt a particular situation to the teachings of claimed
subject matter without departing from the central concept described
herein.
[0058] Therefore, it is intended that claimed subject matter not be
limited to the particular examples disclosed, but that such claimed
subject matter may also include all aspects falling within the
scope of appended claims, and/or equivalents thereof.
* * * * *