U.S. patent application number 11/958265 was filed with the patent office on 2008-07-10 for probes and media for high density data storage.
This patent application is currently assigned to NANOCHIP, INC.. Invention is credited to Thomas F. Rust.
Application Number | 20080165568 11/958265 |
Document ID | / |
Family ID | 32110196 |
Filed Date | 2008-07-10 |
United States Patent
Application |
20080165568 |
Kind Code |
A1 |
Rust; Thomas F. |
July 10, 2008 |
Probes and Media for High Density Data Storage
Abstract
A device in accordance with embodiments of the present invention
comprises a contact probe for high density data storage reading,
writing, erasing, or rewriting. In one embodiment, the contact
probe can include a silicon core having a conductive coating.
Contact probes in accordance with the present invention can be
applied to a phase change media, for example, to form an indicia in
the phase change media by changing the electrical resistivity of a
portion of the phase change media.
Inventors: |
Rust; Thomas F.; (Oakland,
CA) |
Correspondence
Address: |
FLIESLER MEYER LLP
650 CALIFORNIA STREET, 14TH FLOOR
SAN FRANCISCO
CA
94108
US
|
Assignee: |
NANOCHIP, INC.
Fremont
CA
|
Family ID: |
32110196 |
Appl. No.: |
11/958265 |
Filed: |
December 17, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11321136 |
Dec 29, 2005 |
7336524 |
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11958265 |
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10684661 |
Oct 14, 2003 |
7233517 |
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11321136 |
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60418923 |
Oct 15, 2002 |
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Current U.S.
Class: |
365/151 ;
365/174; G9B/5; G9B/5.04; G9B/9.002 |
Current CPC
Class: |
G11B 9/1409 20130101;
G11B 9/1472 20130101; G11B 5/00 20130101; G11B 9/14 20130101; G11B
2005/0002 20130101; G11B 11/20 20130101; B82Y 10/00 20130101; G11B
2005/0005 20130101; G11B 5/127 20130101 |
Class at
Publication: |
365/151 ;
365/174 |
International
Class: |
G11C 11/00 20060101
G11C011/00 |
Claims
1. A system for storing data, the system comprising: a memory
device having a media that is adapted to store data; a probe
electrically connectable with the memory device, the probe
including: a first portion formed from an insulator, and a second
portion formed from a conductor, the second portion being disposed
adjacent to the first portion; wherein the second portion
communicates electrically with the media to perform one of a read
and a write in the media; wherein the media has two or more ranges
of electrical resistivity to represent one or more data.
2. The system of claim 1, wherein when a current is applied between
the probe and the memory device, an electrical resistivity within
one of the two or more ranges of electrical resistivity can be
provided to a portion of the media.
3. The system of claim 1, wherein the probe is electrically
connected with the memory device when the probe contacts the memory
device.
4. The system of claim 1, wherein the media is a phase change
material.
5. A system for storing data, the system comprising: a memory
device having a media that is adapted to store data; a probe
electrically connectable with the memory device, the probe
including: a first portion formed from an insulator, and a second
portion formed from a conductor, the second portion being disposed
adjacent to the first portion; wherein the first portion and the
second portion can simultaneously contact the media and the second
portion communicates electrically with the media to perform one of
a read and a write in the media; wherein the media has two or more
ranges of electrical resistivity to represent one or more data.
6. The system of claim 5, wherein when a current is applied between
the probe and the memory device, an electrical resistivity within
one of the two or more ranges of electrical resistivity can be
provided to a portion of the media.
7. The system of claim 5, wherein the probe is electrically
connected with the memory device when the probe contacts the memory
device.
8. The system of claim 5, wherein the media is a phase change
material.
9. A system for storing data, the system comprising: a memory
device having a media that is adapted to store data; a probe
electrically connectable with the memory device, the probe
including: a first portion formed from an insulator, and a second
portion formed from a conductor, the second portion formed side by
side with the first portion; the first and second portion having
respective adjacent first and second edges, which first and second
edges can simultaneously contact the media; wherein the second
portion communicates electrically with the media to perform one of
a read and a write in the media; wherein the media has two or more
ranges of electrical resistivity to represent one or more data.
10. The system of claim 9, wherein when a current is applied
between the probe and the memory device, an electrical resistivity
within one of the two or more ranges of electrical resistivity can
be provided to a portion of the media.
11. The system of claim 9, wherein the probe is electrically
connected with the memory device when the probe contacts the memory
device.
12. The system of claim 9, wherein the media is a phase change
material.
Description
CLAIM TO PRIORITY
[0001] This application is a continuation of U.S. patent
application Ser. No. 11/321,136 filed on Dec. 29, 2005, entitled
ATOMIC PROBES AND MEDIA FOR HIGH DENSITY DATA STORAGE, which is a
continuation of U.S. patent application Ser. No. 10/684,661 filed
on Oct. 14, 2003, entitled ATOMIC PROBES AND MEDIA FOR HIGH DENSITY
DATA STORAGE, now U.S. Pat. No. 7,233,517 issued on Jun. 19, 2007,
and claims priority to the following U.S. Provisional Patent
Application:
[0002] U.S. Provisional Patent Application No. 60/418,923 entitled
"Atomic Probes and Media for High Density Data Storage," Attorney
Docket No. NANO-01014US0, filed Oct. 15, 2002.
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0003] This application incorporates by reference all of the
following co-pending applications:
[0004] U.S. patent application Ser. No. 10/684,883, entitled
"Molecular Memory Integrated Circuit Utilizing Non-Vibrating
Cantilevers," Attorney Docket No. NANO-01011US1, filed Oct. 14,
2003;
[0005] U.S. patent application Ser. No. 10/684,760, entitled "Fault
Tolerant Micro-Electro Mechanical Actuators," Attorney Docket No.
NANO-01015US1, filed Oct. 14, 2003;
[0006] U.S. patent application Ser. No. 10/685,045, entitled "Phase
Change Media for High Density Data Storage," Attorney Docket No.
NANO-01019US1, filed Oct. 14, 2003;
[0007] U.S. Provisional Patent Application No. 60/418,616 entitled
"Molecular Memory Integrated Circuit Utilizing Non-Vibrating
Cantilevers," Attorney Docket No. NANO-01011US0, filed Oct. 15,
2002;
[0008] U.S. Provisional Patent Application No. 60/418,612 entitled
"Fault Tolerant Micro-Electro Mechanical Actuators," Attorney
Docket No. NANO-01015US0, filed Oct. 15, 2002;
[0009] U.S. Provisional Patent Application No. 60/418,618 entitled
"Molecular Memory Integrated Circuit," Attorney Docket No.
NANO-01016US0, filed Oct. 15, 2002; and
[0010] U.S. Provisional Patent Application No. 60/418,619 entitled
"Phase Change Media for High Density Data Storage," Attorney Docket
No. NANO-01019US0, filed Oct. 15, 2002.
BACKGROUND OF THE INVENTION
[0011] 1. Field of the Invention
[0012] This invention relates to media for high density data
storage in molecular memory integrated circuits for use in
micro-electric mechanical systems (MEMS).
[0013] 2. Description of the Related Art
[0014] Phase change media are used in the data storage industry as
an alternative to traditional recording devices such as magnetic
recorders (tape recorders and hard disk drives) and solid state
transistors (EEPROM and FLASH). CD-RW data storage discs and
recording drives utilize phase change technology to enable
write-erase capability on a compact disc-style media format. Like
other phase change media technology, CD-RWs take advantage of
changes in optical properties when media material is heated above
ambient temperature to induce a phase change from a crystalline
state to an amorphous state.
[0015] Data storage devices using optical phase change media have
enabled inexpensive, medium density storage with the flexibility of
erase and rewrite capability. Unfortunately, current technology
does not enable the very high densities required for use in today's
high capacity portable electronics and tomorrow's next generation
technology such as systems-on-a-chip and MEMs. Consequently, there
is a need for solutions which permit higher density data storage,
while still providing the flexibility of current phase change media
solutions.
SUMMARY OF THE INVENTION
[0016] High density data storage requires a media in which to store
data. One such media is a phase change media that alters its
resistivity when data is written to the media. The media can
include an overcoat. The overcoat can help reduce physical damage
inflicted on the media from a device such as a cantilever tip in a
molecular memory integrated circuit used to write to or read from
the media. Additionally, data written to the media can be in many
states. Hence, the media can store digital data and/or analog
data.
[0017] Other objects, aspects and advantages of the invention can
be obtained from reviewing the figures, specification and
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Further details of the present invention are explained with
the help of the attached drawings in which:
[0019] FIG. 1 is an embodiment of the invention that shows a
cross-section of a media device in an unwritten state.
[0020] FIG. 2 is another embodiment of the invention that shows a
cross-section of a media device including data bit.
[0021] FIG. 3 is another embodiment of the invention that shows a
cross-section of a media device including a data bit where an
embodiment of a cantilever tip is connected with the media
device.
[0022] FIG. 4 is another embodiment of the invention that shows a
cross-section of a media device including a data bit where another
embodiment of another cantilever tip is connected with the media
device.
[0023] FIGS. 5A, 5B, and 5C depict another embodiment of the
invention showing another atomic probe with a coating on five sides
of a core.
[0024] FIGS. 6A, 6B, and 6C depict another embodiment of the
invention showing another atomic probe with a coating on one side
of a core. FIG. 6D depict yet another embodiment of the
invention.
[0025] FIGS. 7A, 7B, and 7C depict another embodiment of the
invention showing another atomic probe with a coating formed on the
end of a core. FIG. 7D depicts yet another embodiment of the
invention.
[0026] FIGS. 8A, 8B, and 8C depict another embodiment of the
invention showing another atomic probe with a coating banded on a
core. FIG. 8D depicts yet another embodiment of the invention.
[0027] FIGS. 9A, 9B, and 9C depict another embodiment of the
invention showing another atomic probe with a coating on one side
of a core, where coating has a protective material connected with
it.
[0028] FIG. 10 is a scanning electron microscope view of another
embodiment of the invention showing another atomic probe with a
coating.
DETAILED DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 is an embodiment of the invention that shows a
cross-section of the media device 100 in an unwritten state. The
media device 100 includes a substrate 102, an undercoat 104, a
media 106 and an overcoat 108. Substrate 102 supports the media
device. Undercoat 104 can be formed on top of substrate 102,
however, undercoat 104 is not required. Next, media 106 is formed
and then an overcoat 108 is placed after the media 106.
[0030] Media device 100 can be made from a variety of materials.
For instance, in one embodiment, media device 100 can include an
undercoat 104. Undercoat 104 can be placed over the substrate. The
substrate is typically a material with a low conductivity. In one
embodiment, undercoat 104 is a highly conductive material. For
instance, one embodiment uses a material for undercoat 104 that
includes tungsten. Yet another embodiment of undercoat 104 includes
platinum. Other embodiments of undercoat 104 can include gold,
aluminum, or copper.
[0031] While undercoat 104 has been described as being a highly
conductive material, undercoat 104 can also be an insulator. For
instance, undercoat 104 can be made from an oxide or nitride
material, thereby insulating the media 106 from the substrate
102.
[0032] In another embodiment, media device 100 includes an overcoat
108. Overcoat 108 is made from a material that is different from
media 106. The overcoat 108 is selected to prevent physical damage
to the media or to the probe tip when the probe tip comes into
contact with overcoat 108. The overcoat is selected to reduce wear
of the overcoat and probe tip over an extended time period.
Overcoat 108 typically has a low conductance characteristic, but a
high hardness characteristic. For instance, in one embodiment
overcoat 108 is made from titanium nitride, which is a poor
conductor, but is hard. In another embodiment, overcoat 108 can be
made of a diamond-like carbon. The conductivity of diamond-like
carbon can be adjusted in the manufacturing process through a
variety of techniques. One such technique includes using a dopant
such as nitrogen in the formation of the diamond-like carbon.
[0033] In yet another embodiment of media device 100, overcoat 108
can be an insulator. For instance, overcoat 108 can be an insulator
such as nitride, for example silicon nitride. If an insulator is
used for overcoat 108, then any current applied to memory device
100 will have to tunnel through the insulator before reaching the
media 106. Thus, in one embodiment, the insulator used for overcoat
108 is kept relatively thin, thereby reducing the amount of
tunneling required before a current can interact with media 106. In
another embodiment, the insulator for overcoat 108 is an oxide. A
number of different insulators are useful for overcoat 108, and
these insulators have an advantage of being very hard.
[0034] In other embodiments of media device 100, media 106 is a
phase change material. In still other embodiments of media device
100, media 106 is a phase change material such as germanium,
tellurium and/or antimony and is commonly known as a chalcogenide.
As a phase change material is subjected to different temperatures,
the phase of the material changes between crystalline and amorphous
states. As a result of this phase change, the resistivity of the
material changes. This resistivity change is quite large in phase
change materials and can be easily detected by a probe tip that has
a conductive coating on it by passing current through the tip and
the media.
[0035] In yet another embodiment of media device 100, media 106 can
be a magneto optic material.
[0036] In addition to overcoat 108, media device 100 can include a
lubricant 101 that is placed on top of overcoat 108. For instance,
in one embodiment, lubricant 101 can be molybdenum disulfide.
Lubricant 101 can be a liquid. Lubricant 101 can also be any number
of thin liquids. Lubricant 101 can be applied to overcoat 108 by
many different methods. In one embodiment, lubricant 101 is
deposited on top of overcoat 108 using a deposition process. In
another embodiment, lubricant 101 is sprayed onto overcoat 108.
[0037] One method of making the media device 100 is with a
traditional semiconductor manufacturing processes. Yet another
method of making media device 100 is to use a shadow mask. Thus, a
mask wafer that contains at least one aperture is placed over a
final wafer, which will contain a memory device 100. The mask wafer
and final wafer are then subjected to a deposition process. During
the deposition process, chemicals pass through the shadow mask and
are deposited to form a media device 100.
[0038] FIG. 2 is another embodiment of the invention that shows a
cross-section of the media device 200 including data bit. Media
device 200 includes a substrate 202, an optional undercoat 204, a
media 206, and an overcoat 208. The media 206 further includes a
data bit 210, which represents data stored in the memory device
200.
[0039] The media can be of many different types. One embodiment is
where media device 200 includes a charge storage type media 206.
Charge storage media stores data as trapped charges in dielectrics.
Thus, for charge storage media, media 206 would be a dielectric
material that traps charges when media 206 includes a written
state. Changing media 206 back to an unwritten state simply
requires the removal of the trapped charges. For instance, a
positive current can be used to store charges in media 206. A
negative current can then be used to remove the stored charges from
media 206.
[0040] Another embodiment is where media device 200 is a phase
change media. Thus, media 206 can include a material that has a
resistance characteristic at an ambient state, but the resistance
characteristic changes in response to temperature changes. For
instance, as a current is applied such that the current passes
through media 206, the temperature of media 206 is increased. After
media 206 is heated to a predetermined temperature, the current is
removed from media 206, causing the temperature of media 206 to
decrease back to the ambient state of media 206. During the cooling
of media 206, the resistivity of media 206 changes from its
original state, the state before the current was applied. This
resistance change is caused by the thermal writing of a crystalline
bit. When the resistive characteristics of media 206 change from
its original state, then media 206 is said to be in a written or
crystalline state. To erase the written state from memory 206, a
second current is applied to media 206. The second current causes
media 206 to heat to a second and higher temperature. The second
current is then removed from media 206, causing media 206 to cool
back to an ambient temperature. As media 206 cools, the resistivity
of media 206 returns to the resistivity media 206 had at its
original amorphous state, or a close approximation to the original
resistivity state of media 206.
[0041] Another embodiment of a phase change material for media 206
requires media 206 to be heated to a higher temperature for a
written state to exist. For instance, applying a first current to
media 206 such that media 206 is heated to a temperature
approximately equal to 170.degree. C. to 200.degree. C. As media
206 cools back to an ambient state, then the resistivity of media
206 will decrease. To reset media 206 back to an unwritten state, a
second current is applied to media 206 causing media 206 to heat to
a temperature somewhere in the range of 600.degree. C. As media 206
cools back to an ambient state, any written state to the area of
media 206 subjected to the second current and heated to 600.degree.
C. will revert back to the resistivity that media 206 possessed
before having been changed to a written state.
[0042] Different materials can be used for media 206 to adjust the
operating range for memory writing and resetting the media 206 back
to an unwritten state. Altering the proportions of the elements in
a chalcogenide is one way of altering the written and erased
temperatures.
[0043] Yet another embodiment of the media device 200 has the
resistivity of media 206 changed in a similar way, except that
media 206 is also self-quenching. Thus, media 206 begins at an
unwritten, ambient state. A first current is applied to media 206,
thereby heating media 206 to a first predetermined temperature. For
instance, a write operation can require that media 206 be heated to
a temperature of at least 170.degree. C. Then, the first current is
removed from media 206 and media 206 begins to cool. As media 206
cools, the resistivity of media 206 changes such that the new
resistivity characteristic can be interpreted as a written state.
This state can cause the resistivity of media 206 to increase or
decrease, depending on the material used for media 206.
Subsequently, to erase the written memory to media 206, a second
current is applied to media 206. Media 206 is heated to a second
temperature (for instance, media 206 can be heated to a temperature
of at least 600.degree. C.). As media 206 cools, the resistivity of
media 206 is returned back to a state approximately equal to the
original state of media 206, thereby erasing the written data in
media 206.
[0044] The written states within media 206, however, can be also be
changed back to the ambient state of media 206, or an unwritten
state, by applying heating to a large region of the memory device
200. For instance, memory device 200 can apply a current to a
buried heater under the memory device 200. This heating can be
applied to all of the memory locations in the memory device 200
such that the resistivity characteristics of media 206 is returned
to the ambient state throughout the entire memory device 200.
[0045] As described above in some of the various embodiments of
media device 200, the ambient, or unwritten, state of memory device
200 has the media 206 having a high resistivity, and the written
state of media 206 having a low resistivity. In other embodiments
these states can be reversed such that the ambient, or unwritten
state, for memory device 200 has media 206 having a low resistivity
and a written state has media 206 having a high resistivity.
[0046] Another embodiment of memory device 200 can have media 206
capable of having a plurality of resistivity states. For example,
at the ambient state, the media 206 of memory device 200 can have a
first resistivity. Media 206 can then be heated to different
temperatures and then cooled, thereby changing the resistivity of
media 206. One embodiment senses whether the resistivity for media
206 is at or near the ambient state for media 206 or at some state
that is sufficiently different to be measured as a state different
than ambient, or unwritten. Another embodiment is able to sense a
plurality of resistivity states that media 206 can possess.
[0047] For instance, media 206 begins with some first resistivity
characteristic at an ambient, or unwritten state. A first current
is then applied to media 206, thereby heating media 206 to a first
temperature. The first current is then removed from media 206,
which thereby begins to cool. As media 206 cools, media 206 gains a
second resistivity characteristic. In one embodiment, the second
resistivity characteristic of media 206 can be measured more
precisely than simply whether the second resistivity characteristic
is different from the first resistivity characteristic. The second
resistivity characteristic can vary depending on the temperature
that the media 206 is heated to by the first current. Thus, the
different resistivity characteristics that can be represented by
the second resistivity characteristic can be representative of a
range of data values. This range of data values can be classified
in discrete ranges to represent analog values. Alternatively, the
precise value of the resistivity characteristic for media 206 can
be measured for more precise analog data storage. Measurements of
the resistivity are preferentially obtained by taking measurements
which are relative to a first state of the media, but can also be
obtained by taking absolute value measurements. Another method of
measurement extracts the data as the derivative of the measured
data.
[0048] Media 206 can posses a large dynamic range for resistivity
states, thereby allowing analog data storage. The dynamic range for
the resistivity characteristic of media 206 can be approximately
1000-10,000 (or 10A3 to 10A4) orders of magnitude. In one
embodiment, however, heating from the probe on the phase change
material can cause only a very small area of media 206 to undergo a
change in its resistivity. In this form a smaller dynamic range may
be observed, as only a small region of the media is altered.
[0049] FIG. 3 is another embodiment of the invention that shows a
cross-section of the media device 300 including a data bit where an
embodiment of an atomic probe 311 is in contact with the media
device 300. Atomic probe 311 includes a core 310 and a coating 312.
Media device 300 includes a substrate 302 connected with undercoat
304. Undercoat 304 of memory device 300 is connected with media
306. Media 306 includes a data bit 314. Media 306 and data bit 314
are connected with overcoat 308. Atomic probe 311 is in contact
with overcoat 308. Memory device 300 can be any one of the
embodiments described above in FIGS. 1 and 2.
[0050] One embodiment of the atomic probe 311 includes core 310 and
coating 312 with a generally conical shape. For instance, atomic
probe 311 has a generally conical shape, however, atomic probe 311
can also be described as having a generally trapezoidal shape.
Atomic probe 311 can have a radius of curvature 313 from a few
nanometers to as much as fifty nanometers or more. The radius of
curvature 313 is measured from a line 309 generally extending down
the center of the atomic probe 311. Atomic probe 311 is generally
symmetrical along the line 309, but as will be seen below, atomic
probe 311 is not limited to being symmetrical along the line
309.
[0051] In one embodiment, either to write a data bit 314 or read a
data bit 314 to the memory device 300, the atomic probe 311 should
make contact with the memory device 300. This contact can occur
where atomic probe 311 contacts the overcoat 308 of the memory
device 300. The point of contact on the atomic probe 311 is
generally conductive. Thus, in one embodiment, the atomic probe 311
includes a core 310, which is an insulator, that is partially
covered by a conductive coating 312. The coating 312 of atomic
probe 311 makes contact with overcoat 308 of memory device 300
during access of memory device 300.
[0052] In another embodiment of the invention, during a read
operation, atomic probe 311 does not have to make direct contact
with overcoat 308 of memory device 300. Instead, atomic probe 311
is brought in close proximity with memory device 300 such that
coating 312 can sense whether a piece of data 314 exists. For
instance, if memory device 300 were of a charged storage type
memory, then atomic probe 311 would sense the electric and/or
magnetic field strength of data 314 through coating 312.
[0053] In one embodiment, the core 310 of atomic probe 311 can
include oxides, amorphous silicon, or other insulators. The coating
312 of atomic probe 311 is a conductor and can include any number
of different components. For instance, coating 312 can include
titanium nitride, platinum, gold, aluminum, tungsten, tungsten
carbide, tungsten oxide, diamond-like carbon, platinum iridium,
copper, doped silicon or a mixture of such conductors. The choice
of material for coating 312 of atomic probe 311 is influenced by
the chosen application for the atomic probe 311. For instance, some
applications require the coating 312 to be an exceptional conductor
like platinum, while others do not require such a high
conductivity. Titanium nitride can be used for coating 312 and
would be beneficial if the application valued a hard coating 312
over a highly conductive coating 312.
[0054] One embodiment of the invention controls the shape of the
coating 312 such that it is rectangular in shape. Thus, during a
write function to the memory device 300, the data 314 formed will
have a generally rectangular shape as opposed to a spherical
shape.
[0055] FIG. 4 is another embodiment of the invention that shows a
cross-section of the media including a data bit where another
embodiment of another cantilever tip, or atomic probe 411, is
connected with the media. Again, a media device 400 is shown that
can be any of the memory devices previously discussed. Media device
400 includes a substrate 402, an undercoat 404, a media 406, and an
overcoat 408. Media device 400, as shown, has been written to and a
bit of data 414 formed. Atomic probe includes a core 410 connected
with a coating 412.
[0056] Shown in FIG. 4, is an embodiment of the invention where the
coating 412 of atomic probe 411 is only on one side of atomic probe
411. Thus, when atomic probe 411 makes contact with media device
400, a smaller portion of atomic probe 411 can potentially affect
media device 400. For instance, during a write operation by the
atomic probe 411 where media 400 is a phase change media, coating
412 provides a path for conducting a current through media device
400. The contact area of coating 412 is smaller than the contact
area of coating 312 from FIG. 3. Thus, the amount of media 406 that
can be influenced by a current flowing through coating 412 is less
than the amount of media 306 that can be influenced by a current
flowing through coating 312 from FIG. 3.
[0057] FIGS. 5A, 5B, and 5C depict another embodiment of the
invention showing another atomic probe 520 with a coating 524 on
five sides of a core 522. FIG. 5 shows three views of atomic probe
520. FIG. 5A is a side view of atomic probe 520 where coating 524
is connected with core 522. As can be seen in FIG. 5A, coating 524
covers an entire side of atomic probe 520. FIG. 5B is a top view of
atomic probe 520. FIG. 5B shows that the coating 524 protects the
core 522 along five surfaces. The center square portion of FIG. 5B
is the area that makes contact with a media device. One such media
device can be similar to media device 300 of FIG. 3. FIG. 5C shows
a three dimensional view of atomic probe 520. As can be seen from
FIG. 5C, coating 524 extends away from core 522.
[0058] FIGS. 6A, 6B, and 6C depict another embodiment of the
invention showing another atomic probe 620 with a coating 624 on
one side of a core 622. FIG. 6 shows three views of atomic probe
620. FIG. 6A is a side view of atomic probe 620 where coating 624
is connected with core 622. Coating 624 is only on one side of core
622 in FIG. 6. Also, coating 624 extends past the tip 623 of core
622 or may be even with the end of core 622. Thus, as the atomic
probe 620 is brought into contact with a media device, coating 624
will make contact with the media device. FIG. 6B shows a top view
of atomic probe 620 and FIG. 6C shows a three dimensional view of
atomic probe 620 with the coating 624 only on one side of core
622.
[0059] In an alternative embodiment, coating 624 can be flush with
the tip 623 of core 622 similar to the atomic probe 411 shown in
FIG. 4.
[0060] In another embodiment of the invention, the coating 634 of
FIG. 6D does not rest to the side of core 642, as shown in FIG. 6A,
but rather, coating 634 is embedded into core 642. An example of
this would be applying a preferential doping to one side of a
single crystal silicon core, causing the embedded area to be
conductive, while the core would remain substantially an
insulator.
[0061] FIGS. 7A, 7B and 7C depict another embodiment of the
invention showing another atomic probe 720 with a coating 724
formed on the end of a core 722. In the embodiment of the invention
shown in FIG. 7, coating 724 is has a generally button like shape.
Unlike the embodiments of the invention shown in FIGS. 5C and 6C,
the coating 724 in FIG. 7C has a generally cylindrical shape. FIG.
7B shows a top view of atomic probe 720 and FIG. 7C shows a three
dimensional view of atomic probe 720.
[0062] The material used for coating 724 can be any of the
materials previously disclosed. In an alternative embodiment,
however, coating 724 can include carbon nano-tubes. Carbon
nano-tubes are useful because they are very small with known
dimensions. Thus, the cross-section of a carbon nano-tube is very
small. Furthermore, carbon nano-tubes are very strong, thus they
can provide the hardness needed for extended life of an atomic
probe. Moreover, the structural make-up of a carbon nano-tube
coating is capable of handling temperatures well in excess of
600.degree. C.
[0063] In another embodiment of the invention, the coating 734 of
FIG. 7D does not rest top of core 742, as shown in FIG. 7, but
rather, coating 734 is embedded into core 742.
[0064] In these embodiments the core is conductive, or the core is
coated with a conductive coating, such that a conductive path
exists between the carbon nanotube and the probe. There also exists
a conductive path to the cantilever conductor on which the atomic
probe sits.
[0065] FIGS. 8A, 8B, and 8C depict another embodiment of the
invention showing another atomic probe 820 with a coating 822
banded on a core 824. FIG. 8A shows coating 824 draped over the
core 822 of atomic probe 820. FIG. 8B shows how coating 824 is a
thin piece of material relative to the dimensions of the core 822.
FIG. 8C is a three dimensional view of atomic probe 820 showing how
the coating 824 is draped over core 822. In another embodiment,
FIG. 8D, coating 834 is also recessed into core 842. The reduced
contact area of coating 824, or coating 834, shrinks the affected
media, of a media device, when signals are passed through the
coating 824, or the coating 834, contact is made with a media
device by the coating 824, or the coating 834. Thus, during a write
operation, less media is influenced by the atomic probe 820.
Consequentially, more data can be stored in a media device than if
a coating 824, or coating 834, with a larger contact surface were
used.
[0066] FIGS. 9A, 9B and 9C depict another embodiment of the
invention showing another atomic probe 920 with a coating 924 on
one side of a core 922, where coating 924 has a protective material
926 connected with it. FIG. 9A shows a side view of atomic probe
920. Core 922 is connected with coating 924. Coating 924 is also
connected with a protective material 926. FIG. 9B shows a top view
of atomic probe 920 and FIG. 9C shows a three dimensional view of
atomic probe 920.
[0067] As atomic probe 920 makes contact with a media device, the
atomic probe 920 can be dragged or pushed along the media device.
Such actions can cause mechanical stresses on the atomic probe 920,
and coating 924 in particular. The addition of protective material
926 gives additional support to coating 924, reducing the chance of
coating 924 suffering damage due to contact with the media
device.
[0068] FIG. 10 is a scanning electron microscope view of another
embodiment of the invention showing another atomic probe. As can be
seen from FIG. 10, an atomic probe 1020 is shown with a tip 1030.
The diameter of the base of the atomic probe 1020 is less than two
micrometers as can be seen by the scale 1032.
[0069] The foregoing description of the present invention have been
presented for purposes of illustration and description. It is not
intended to be exhaustive or to limit the invention to the precise
forms disclosed. Many modifications and variations will be apparent
to practitioners skilled in this art. The embodiments were chosen
and described in order to best explain the principles of the
invention and its practical application, thereby enabling others
skilled in the art to understand the invention for various
embodiments and with various modifications as are suited to the
particular use contemplated. It is intended that the scope of the
invention be defined by the following claims and their
equivalents.
* * * * *