U.S. patent application number 15/905426 was filed with the patent office on 2018-07-12 for method of marking material and system therefore, and material marked according to same method.
The applicant listed for this patent is Chow Tai Fook Jewellery Company Limited. Invention is credited to Ho CHING, Koon Chung HUI, Ching Tom KONG.
Application Number | 20180193814 15/905426 |
Document ID | / |
Family ID | 50478242 |
Filed Date | 2018-07-12 |
United States Patent
Application |
20180193814 |
Kind Code |
A1 |
HUI; Koon Chung ; et
al. |
July 12, 2018 |
METHOD OF MARKING MATERIAL AND SYSTEM THEREFORE, AND MATERIAL
MARKED ACCORDING TO SAME METHOD
Abstract
A method of forming one or more protrusions on an outer surface
of a polished face of a solid state material, said method including
the step of applying focused inert gas ion beam local irradiation
towards an outer surface of a polished facet of a solid state
material in a way of protruding top surface material; wherein
irradiated focused inert gas ions from said focused inert gas ion
bean penetrate the outer surface of said polished facet of said
solid state material; and wherein irradiated focused inert gas ions
cause expansive strain within the solid state crystal lattice of
the solid state material below said outer surface at a pressure so
as to induce expansion of solid state crystal lattice, and form a
protrusion on the outer surface of the polished face of said solid
state material.
Inventors: |
HUI; Koon Chung; (Tseung
Kwan O, HK) ; CHING; Ho; (Kowloon, HK) ; KONG;
Ching Tom; (New Territories, HK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Chow Tai Fook Jewellery Company Limited |
Central |
|
HK |
|
|
Family ID: |
50478242 |
Appl. No.: |
15/905426 |
Filed: |
February 26, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14290369 |
May 29, 2014 |
9901895 |
|
|
15905426 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01J 19/081 20130101;
C30B 33/04 20130101; H01J 37/00 20130101; C30B 29/04 20130101; C30B
29/34 20130101; C30B 29/16 20130101; H01J 37/317 20130101; C30B
29/20 20130101; H01J 2237/31737 20130101; Y10T 428/24355 20150115;
H01J 2237/31713 20130101; B41M 3/14 20130101 |
International
Class: |
B01J 19/08 20060101
B01J019/08; C30B 33/04 20060101 C30B033/04; C30B 29/04 20060101
C30B029/04; H01J 37/00 20060101 H01J037/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 30, 2013 |
HK |
13106425.7 |
Claims
1. A method of forming one or more protrusions on an outer surface
of a polished facet of a solid state material, said method
including the step of: (i) applying focused inert gas ion beam
local irradiation towards an outer surface of a polished facet of a
solid state material in a way of protruding top surface material;
wherein irradiated focused inert gas ions from said focused inert
gas ion beam penetrate the outer surface of said polished facet of
said solid state material; and wherein irradiated focused inert gas
ions cause expansive strain within the solid state crystal lattice
of the solid state material below said outer surface at a pressure
so as to induce expansion of solid state crystal lattice, and form
a protrusion on the outer surface of the polished facet of said
solid state material.
2. A method of forming one or more protrusions according to claim
1, wherein said focused inert gas ion beam has a beam energy in the
range of from 5 keV to 50 keV and probe current in the range of 1
fA to 200 pA.
3. A method of forming one or more protrusions according to claim
1, wherein the solid state crystal lattice is in a form of a single
crystalline, poly-crystalline, or an amorphous form.
4. A method of forming one or more protrusions according to claim
1, wherein the solid state material is a material in solid state
form under ambient temperature and under a pressure from
atmospheric to high vacuum.
5. A method of forming one or more protrusions according to claim
1, wherein the solid state material is a precious stone, preferably
selected from the group including Diamond, Ruby, Sapphire, Emerald,
Pearl, Jade or the like.
6. A method of forming one or more protrusions according to claim
1, wherein the focused inert gas ion beam is an ion source from any
inert gas in Group VIII of the periodic table.
7. A method of forming one or more protrusions according to claim
1, wherein the polished facet of the solid state material has an
average surface roughness of less than 50 nm.
8. A method of forming one or more protrusions according to claim
1, wherein said protrusion has an average width in the nanometer or
micrometer order of magnitude, and an average height in the
nanometer or micrometer order of magnitude.
9. A method of forming one or more protrusions according to claim
1, wherein the distance from the outer surface of said solid state
material to the region of irradiated inert gas accumulation below
the outer surface is in the range of from 1 nm to 100 .mu.m.
10. A method of forming one or more protrusions according to claim
1, wherein said one or more protrusions is provided so as to form
an identifiable mark or pattern.
11. A method of forming one or more protrusions according to claim
10, wherein the identifiable mark is in a form of a single or array
of dot, pillar, dome, hemisphere, line, irregular shape, symmetric
or asymmetric shape, or the like, wherein the identifiable mark may
be provided as a periodic line array, hole/dot array, circular
array, spiral array, fractal array or multiple periods array, or
the like.
12. A method of forming one of more protrusions according to claim
10, wherein the identifiable mark is provided as a continuous
protruded shape to form arbitrary patterns.
13. A method of forming one or more protrusions according to claim
1, wherein a plurality of protrusions are formed and are nanometer
sized so as to provide an information mark invisible to the naked
eye due to Rayleigh Criterion in optical limit.
14. A method of forming one or more protrusions according to claim
13, wherein said protrusions are arranged in a periodic array
viewable by specified lighting conditions and by a camera equipped
microscope in the visible and invisible light range.
15. A method of forming one or more protrusions according to claim
1, wherein said one or more protrusions forms an identifiable
security mark.
16. A method of forming one or more protrusions according to claim
1, wherein the integrity of said solid state material is preserved,
and there exists substantially no loss in mass.
17. A solid state material having one or more protrusions formed on
an outer surface of a polished facet of the solid state material,
wherein said one or more protrusions are formed by a method
according to claim 1.
18. A system for forming one or more protrusions on an outer
surface of a polished facet of a solid state material, wherein said
one or more protrusions are formed by a method according to claim
1.
Description
CROSS-REFERENCE TO PRIORITY APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/290,369, filed May 29, 2014, now U.S. Pat.
No. 9,901,895, which, in turn, claims priority to Hong Kong Short
Term Patent Application No. 13106425.7, filed May 30, 2013. Each of
these priority patent applications is incorporated herein by
reference in its entirety for all purposes.
FIELD OF THE INVENTION
[0002] The present invention relates to a method of providing a
marking on a solid state material. In particular, the present
invention relates to providing a marking on a surface of a solid
state material such as a gemstone or the like, whereby the marking
is not optically viewable.
BACKGROUND OF THE INVENTION
[0003] Marking of solid materials, in particular precious gemstones
or the like, may be required for example in identification or
quality markings. For the marking of gemstones, it is desirable
that marking be performed in a manner such that the gemstone is not
damaged or any damage is minimised, the integrity of the gemstone
is preserved, no significant loss in mass occurs, no chemical
residue remains, and the marking does not detract from the clarity
or colour of the gemstone.
[0004] For ornamental gemstones, the marking technique should not
be visible to the naked eye so as not to detract from the quality
of the stone from an aesthetic standpoint, whereby visible
identification of marking may detract from the visual result in
devaluation of a gemstone.
[0005] The techniques of etching, engraving and micro-milling
processes exist in the prior art, which may impact on the integrity
and quality of a gemstone, and may be viewed unfavourably.
Furthermore, such processes result in some amount of loss of
material, again which may be viewed unfavourably.
[0006] Other marking techniques exist within the prior art
including those such as disclosed in U.S. Pat. No. 6,391,215B1,
whereby an information mark is applied to a polished facet of a
diamond or silicon carbide gemstone whereby the gemstone is coated
with an electrically conductive layer. The electrically conductive
layer prevents the gemstone from becoming charged and the mark is
formed by a focused ion beam whereby a portion of the surface is
ablated to a requisite depth, and whereby the surface to which the
mark is applied is subsequently cleaned utilising a powerful
oxidizing agent.
OBJECT OF THE INVENTION
[0007] Accordingly, it is an object of the present invention to
provide a method of providing a marking on a solid state material
and a solid state material having said marking thereon, which
overcomes or at least partly ameliorates at least some of the
deficiencies as associated with the prior art.
SUMMARY OF THE INVENTION
[0008] In a first aspect, the present invention provides a method
of forming one or more protrusions on an outer surface of a
polished facet of a solid state material, said method including the
step of:
[0009] (i) applying focused inert gas ion beam local irradiation
towards an outer surface of a polished facet of a solid state
material in a way of protruding top surface material;
[0010] wherein irradiated focused inert gas ions from said focused
inert gas ion beam penetrate the outer surface of said polished
facet of said solid state material; and
[0011] wherein irradiated focused inert gas ions cause expansive
strain within the solid state crystal lattice of the solid state
material below said outer surface at a pressure so as to induce
expansion of solid state crystal lattice, and form a protrusion on
the outer surface of the polished facet of said solid state
material.
[0012] Preferably, the focused inert gas ion beam has a beam energy
in the range of from 5 keV to 50 keV and probe current in the range
of 1 fA to 200 pA.
[0013] The solid state crystal lattice may be in the form of a
single crystalline, poly-crystalline, or amorphous form, and the
solid state material is a material in solid state form under
ambient temperature and under a pressure from atmospheric to high
vacuum.
[0014] Prefer ably the solid state material is a precious stone.
More preferably, the solid state material is a material selected
from the group including Diamond, Ruby, Sapphire, Emerald, Pearl,
Jade or the like.
[0015] The focused inert gas ion beam is an ion source which may be
selected from any inert gas in Group VIII of the periodic
table.
[0016] Preferably, the polished facet of the solid state material
has an average surface roughness of less than 50 nm.
[0017] Preferably, the protrusion has an average width in the
nanometer or micrometer order of magnitude, and an average height
in the nanometer or micrometer order of magnitude.
[0018] The distance from the outer surface of said solid state
material to the region of irradiated inert gas accumulation below
the outer surface is preferably in the range of from 1 nm to 100
.mu.m.
[0019] The protrusion may be provided so as to form an identifiable
mark or pattern, and the identifiable mark is in the form of a
single or array of dot, pillar, dome, hemisphere, line, irregular
shape, symmetric or asymmetric shape, or the like.
[0020] The identifiable mark may be provided as a periodic line
array, hole/dot array, circular array, spiral array, fractal array
or multiple periods array, or the like.
[0021] Alternatively, the identifiable mark may be provided as a
continuous protruded shape to form arbitrary patterns.
[0022] A plurality of protrusions may be formed that are nanometer
sized so as to provide an information mark invisible to the naked
eye due to Rayleigh Criterion in optical limit. The protrusions may
be arranged in a periodic array viewable by specified lighting
conditions and by a camera equipped microscope in the visible and
invisible light range. The one or more protrusions forms an
identifiable security mark.
[0023] The method preferably maintains integrity of said solid
state material such that there exists substantially no loss in
mass.
[0024] In a second aspect, the present invention provides a solid
state material having one or more protrusions formed on an outer
surface of a polished facet of the solid state material, wherein
said one or more protrusions are formed from a method including the
step of:
[0025] (i) applying focused inert gas ion beam local irradiation
towards an outer surface of a polished facet of a solid state
material in a way of protruding top surface material;
[0026] wherein irradiated focused inert gas ions from said focused
inert gas ion beam penetrate the outer surface of said polished
facet of said solid state material; and
[0027] wherein irradiated focused inert gas ions cause expansive
strain within the solid state crystal lattice of the solid state
material below said outer surface at a pressure so as to induce
expansion of solid state crystal lattice, and form a protrusion on
the outer surface of the polished facet of said solid state
material.
[0028] Preferably, the focused inert gas ion beam has a beam energy
in the range of from 5 keV to 50 keV and probe current in the range
of 1 fA to 200 pA.
[0029] The solid state crystal lattice may be in a form of single
crystalline, poly-crystalline, or amorphous form. The solid state
material is a material in solid state form under ambient
temperature and under a pressure from atmospheric to high
vacuum.
[0030] The solid state material is preferably a precious stone, and
more preferably selected from the group including Diamond, Ruby,
Sapphire, Emerald, Pearl, Jade or the like.
[0031] The focused inert gas ion beam utilised to form said one or
more protrusions is an ion source which may be selected from any
inert gas in Group VIII of the periodic table.
[0032] Preferably, the polished facet of the solid state material
has an average surface roughness of less than 50 nm.
[0033] The protrusion preferably has an average width in the
nanometer or micrometer order of magnitude, and an average height
in the nanometer or micrometer order of magnitude.
[0034] Preferably, the distance from the outer surface of said
solid state material to the region of irradiated inert gas
accumulation below the outer surface is in the range of from 1 nm
to 100 .mu.m.
[0035] The one or more protrusions are preferably provided so as to
form an identifiable mark or pattern. The identifiable mark may be
in a form of single or array of dot, pillar, dome, hemisphere,
line, irregular shape, symmetric or asymmetric shape, or the
like.
[0036] Alternatively, the identifiable mark may be provided as a
periodic line array, hole/dot array, circular array, spiral array,
fractal array or multiple periods array, or the like, or the
identifiable mark may be provided as a continuous protruded shape
to form arbitrary patterns.
[0037] The solid state material may have a plurality of protrusions
formed which are nanometer sized so as to provide an information
mark invisible to the naked eye due to Rayleigh Criterion in
optical limit. The protrusions may be arranged in a periodic array
viewable by specified lighting conditions and by a camera equipped
microscope in the visible and invisible light range.
[0038] The one or more protrusions may form an identifiable
security mark.
[0039] The integrity of solid state material is preserved such that
during formation of the one or more protrusions, there exists
substantially no loss in mass of the solid state material.
[0040] In a third aspect, the present invention provides a system
for forming one or more protrusions on an outer surface of a
polished facet of a solid state material, said system
including:
[0041] a focused inert gas ion beam device for applying focused
inert gas ion beam local irradiation towards an outer surface of a
polished facet of a solid state material
[0042] a computer control device for controlling discharge of a
focused inert gas ion beam local irradiation towards an outer
surface of a polished facet of a solid state material,
[0043] wherein the computer control device controls irradiated
focused inert gas ions from said focused inert gas ion beam so as
to penetrate the outer surface of said polished facet of said solid
state material; and irradiated focused inert gas ions cause
expansive strain within the solid state crystal lattice of the
solid state material below said outer surface at a pressure so as
to induce expansion of solid state crystal lattice, and so as to
form a protrusion on the outer surface of the polished facet of
said solid state material.
[0044] Preferably, the focused inert gas ion beam device has a beam
energy in the range of from 5 keV to 50 keV and probe current in
the range of 1 fA to 200 pA.
[0045] The focused inert gas ion beam utilised to form said one or
more protrusions is an ion source which may be selected from any
inert gas in Group VIII of the periodic table.
[0046] The system provides a protrusion having an average width in
the nanometer or micrometer order of magnitude, and an average
height in the nanometer or micrometer order of magnitude.
[0047] Preferably, the system is adapted to provide a protrusion
whereby the distance from the outer surface of said solid state
material to the region of irradiated inert gas accumulation below
the outer surface is in the range of from 1 nm to 100 .mu.m.
[0048] The system is adapted so as to provide an identifiable mark
or pattern on an outer surface of a polished facet of a solid state
material. The identifiable mark provided by the system may be in a
form of a single or array of dot, pillar, dome, hemisphere, line,
irregular shape, symmetric or asymmetric shape, or the like.
[0049] Alternatively, the identifiable mark may be provided as a
periodic line array, hole/dot array, circular array, spiral array,
fractal array or multiple periods array, or the like. The
identifiable mark may be provided as a continuous protruded shape
to form arbitrary patterns.
[0050] Preferably, the system is adapted to provide a plurality of
protrusions which are nanometer sized so as to provide an
information mark invisible to the naked eye due to Rayleigh
Criterion in optical limit.
[0051] The system is preferably adapted so as to provide a
plurality of protrusions which are arranged in a periodic array
viewable by specified lighting conditions and by a camera equipped
microscope in the visible and invisible light range.
[0052] The system may be adapted to provide one or more protrusions
so as to form an identifiable security mark.
[0053] The system is adapted so as to maintain the integrity of
said solid state material during formation of the one or more
protrusions, and such that there exists substantially no loss in
mass of the solid state material.
[0054] Preferably, the system is adapted so as to provide one or
more protrusions on the outer surface of a precious stone. More
preferably, the system is adapted so as to provide one or more
protrusions on the outer surface of a Diamond, Ruby, Sapphire,
Emerald, Pearl, Jade or the like.
[0055] The system is preferably adapted so as to provide one or
more protrusions on a polished facet of the solid state material
having an average surface roughness of less than 50 nm.
[0056] The system is preferably adapted so as to provide one or
more protrusions on the outer surface of a solid state material,
wherein the one or more protrusions has an average width in the
nanometer or micrometer order of magnitude, and an average height
in the nanometer or micrometer order of magnitude.
[0057] Preferably, the system is adapted so as to provide one or
more protrusions on the outer surface of a solid state material
such that the region of irradiated inert gas accumulation below the
outer surface is in the range of from 1 nm to 100 .mu.m.
BRIEF DESCRIPTION OF THE DRAWINGS
[0058] Preferred embodiments of the present invention will be
explained in further detail below by way of examples and with
reference to the accompanying drawings, in which:--FIG. 1 shows an
exemplary schematic diagram of a configuration of a focused inert
gas ion beam system as utilised in embodiments of the present
invention;
[0059] FIG. 2 shows an exemplary schematic representation of a
computer stimulated interaction volume of incident energetic
focused inert gas ions with a solid state material specimen at a
top surface region, in accordance with embodiments of the present
invention;
[0060] FIG. 3 shows an exemplary schematic representation depicting
interaction of primary incident energetic inert gas ion with a
solid state specimen, the Figure showing the production of charged
particles such as electrons and ions along the displaced path of
incident ion, in accordance with embodiments of the present
invention;
[0061] FIG. 4 depicts an ion microscope image of an experimentally
protruded array of nanometer sized dots, in accordance with
embodiments of the present invention;
[0062] FIG. 5 depicts an ion microscope image of a further
experimentally protruded array of nanometer sized dots, in
accordance with embodiments of the present invention;
[0063] FIG. 6 depicts an ion microscope image of another
experimentally protruded array of nanometer sized dots, in
accordance with embodiments of the present invention;
[0064] FIG. 7a depicts a graph showing a schematic representation
of a surface profile of an untreated flat surface;
[0065] FIG. 7b depicts a graph of a schematic representation of the
profile of protruded surface according to embodiments of the
present invention;
[0066] FIG. 8 depicts a schematic three-dimensional contour
representation of a protruded surface profile on a flat surface
with proportional dimensions in reference to the experimental
results as described with reference to FIGS. 4, 5 and 6;
[0067] FIG. 9a depicts an ion microscope image of an untreated
surface on a single crustal diamond facet with a programmed dot
array to be incident by focused inert gas ion beam in accordance
with embodiments of the present invention; and
[0068] FIG. 9b depicts an ion microscope image of the surface of
the single crystal diamond facet of FIG. 9a, after incident by
focused inert bas ion beam at assigned position on the diamond
specimen surface, in accordance with embodiments of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0069] Referring to FIG. 1, there is shown an exemplary schematic
diagram of a configuration of a focused inert gas ion beam system
100 as utilised in accordance with embodiments of the marking
method of the present invention.
[0070] In comparison to typical scanning electron microscopy (SEM),
the focused inert gas ion beam system 100 has a similar basic
configuration, whereby the schematic diagram of FIG. 1 shows the
configuration of a focused inert gas ion beam system 100 for
producing and imaging the protruded array of nanometer sized dots
in accordance with embodiments of the present invention is
shown.
[0071] The gas sources 101 at the top of the electrostatic lens
column 102 may be any known inert gases in Group VIII of the
periodic table, and the choice of inert gas sources utilised
depends on the requisite resulting resolution and fabrication time.
Further, an inert gas is preferably utilised in order to minimise
any alterations in electrical, optical, or chemical properties of a
specimen to be marked.
[0072] For example, for the fabrication of protruded nanometer
sized dots is shown and discussed further below in reference to
FIG. 4, FIG. 5 and FIG. 6, a low pressure of the inert gas with
light atomic mass is preferred, such as Helium or Neon gas for the
gas source 101 of the focused inert gas ion beam system 100.
[0073] Once the inert gas ion is emitted from the gas source 101,
it is accelerated and focused along the top of the electrostatic
lens column 102, and then deflected by scanning deflectors 103 and
104 which are controlled by a computer system, typically a
mainframe computer control system or the like, which finally forms
a scanning focused inert gas ion beam 105 to incident on surface of
a specimen 109.
[0074] During the scanning or continuous incident of the focused
inert gas ion beam 105 to incident on surface of the specimen 109,
a beam 108 of electrons or negative charges emitted from an
emission device 106 and 107, such as electron flood gun or charge
compensator, is used to compensate the positively charged up
specimen surface 109 due to continuous incident of gas ions on
specimen surface 109.
[0075] As the charged up ions inhibit further incident of focused
inert gas ions 105, this results in image burr or drift in position
or shape of a requisite protruded mark.
[0076] During incident of the focused inert gas ion beam 105 on the
surface of the specimen 109, the interaction of incident inert gas
ions with the surface of the specimen 109 produces different
charged species 110 such as electrons or ions which are detected by
an ion or electron detector 111 for imaging, species qualification
and quantification.
[0077] Referring to FIG. 2, there is shown an exemplary schematic
representation of a computer simulated interaction volume of
incident energetic focused inert gas ions with a solid state
material specimen 203 at a top surface region, 202 in accordance
with the present invention, whereby an example of the computer
simulated Monte Carlo plot is depicted showing of the trajectory of
the incident ions 204 during the interaction of an incident
energetic focused inert gas ion beam 201 with a top surface region
202 of a solid state material specimen 203.
[0078] The Monte Carlo simulation of the interaction is based upon
Helium ion as the source of incident energetic focused inert gas
ion beam 201 which is accelerated at 30 keV and the solid state
material specimen 203 is silicon substrate.
[0079] The cross-section of interaction volume of the solid state
material specimen 203 is defined with the penetration depth 205 and
dispersed width 206 which is perpendicular to penetration depth 205
of incident ions, and the Monte Carlo simulated numerical results
of the penetration depth 205 and dispersed width 206 is about 100
nm. Further, due to a high penetration depth and less lateral
straggle of Helium gas ion into the silicon substrate, the size of
the focused ion beam spot 207 at the top surface region 202, in
range of 10 nm, is as small as 1 nm or less in order to fulfill the
requisite criteria of embodiments of the present invention in
creating requisite nanometer sized structures or marks.
[0080] Referring to FIG. 3, the detailed interaction of incident
energetic inert gas ion 301 with a solid state material 305 as
utilised in accordance with embodiments of the present invention is
schematically shown.
[0081] For explanatory purposes of embodiments of the present
invention, the experimental environment is assumed to be in high
vacuum, such as at pressure of 5.times.10.sup.-6 Torr or lower
pressure, and the energetic inert gas ion 301 incident along the
path 302 is at an incident angle 303 to the surface or interface
304 between vacuum and the solid state specimen 305.
[0082] At the instance of energetic inert gas ion 301 incident at
the specimen surface or interface 304, possible energetic species
306 may be generated such as secondary electrons, Auger electrons,
X-ray, secondary ions, sputtered particles from the solid state
specimen 305, or even back-scattered energetic inert gas ion
301.
[0083] The circumstance of said possible energetic species depends
on the atomic mass and carried energy of energetic inert gas ion
301, density and crystallinity of the solid state specimen 305,
chemical bonding between atoms, and the charge state of the
specimen surface or interface 304.
[0084] If the energetic inert gas ion 301 has sufficient energy,
then there exists a high probability of entry of said energetic
species into the solid state specimen 305 and continued to
penetration.
[0085] Along the propagation paths 309 and 312, the energetic inert
gas ion 301 may possibly undergo inelastic collision with adjacent
atoms inside the solid state specimen 305, and one possibility is
the generation of energetic species 311 such as secondary ion or
secondary electron and possibly coming along the path 310 out from
the specimen surface or interface 304.
[0086] Another possibility is for said possible energetic species
to stop at certain local regions for example 308 and 313 as
depicted inside the solid state specimen 305 due to energy loss as
resulting in accumulation of inert gas ion or amorphisation of
crystalline at local regions 308 and 313.
[0087] By appropriate control of the condition of the incident
angle 303 of the energetic inert gas ion 301, accelerating voltage,
and species selection of energetic inert gas ion 301, the incident
energetic inert gas ion 301 has high probability to stop at region
308 and result in either or both accumulation of inert gas ion or
amorphisation of crystalline at local region which has lower
density but larger volume than crystalline structure.
[0088] Thus, local internal strain is built up within the solid
state specimen 305 slightly below the specimen surface or interface
304 which finally leads to expansion of solid state crystalloid
lattice at the specimen surface or interface 304, hence resulting
in the formation of a protruded dot 307 in accordance with
embodiments of the present invention.
[0089] Referring to the ion microscope image as depicted in FIG. 4,
there is shown an experimentally protruded array of nanometer sized
dots 401 on single crystal diamond facet 402 by the focused inert
gas ion beam system.
[0090] The acceleration voltage of gas ions utilised is about 35
kV, and the beam current utilised is about 0.5 pA with ions dose of
about 0.1 nC/.mu.m.sup.2, and the dwell time is of about 1 us. As
will be understood, other applicable acceleration voltages and beam
currents may be utilised, whilst falling within the scope of the
present invention. For example, a focused inert gas ion beam device
utilising focused inert gas ion beam having a beam energy in the
range of from 5 keV to 50 keV and probe current in the range of 1
fA to 200 pA, will be understood to be applicable, although
utilizing equipment capable of generating parameters outside of 5
keV to 50 keV and probe current in the range of 1 fA to 200 pA, may
also be considered by those skilled in the art to be applicable to
embodiments of the present invention.
[0091] The incident position of the focused inert gas ion beam is
programmed by the computer and then controlled by scanning lens
column 103 and 104 as exemplified and described with to FIG. 1, and
as results as shown in FIG. 4, the array of 3.times.3 protruded
nanometer sized dots is formed with each protruded nanometer sized
dots 401 having diameter of about 130 nm and the vertical period
403 and horizontal period 405 with reference to the plane of the
diamond facet 402, displacement between centers of adjacent
protruded nanometer sized dots 401, are same of about 200 nm.
[0092] The field of view of whole image in this example as shown in
both vertical and horizontal directions is 2.00 .mu.m.times.2.00
.mu.m under magnification of 57,150.times., which in this example
is imaged by the same focused inert gas ion beam system after
fabrication of protruded nanometer sized dots 401, and with the
same acceleration voltage of gas ions but less beam current than
under scanning mode.
[0093] The scale bar 404 is shown for reference to the dimension of
the protruded nanometer sized dots 401.
[0094] Similarly to FIG. 4, FIG. 5 shows an exemplary embodiment of
a protruded array of nanometer sized dots 501 fabricated by the
focused inert gas ion beam system on single crystal diamond facet
502, however the diameter of the protruded nanometer sized dots 501
in this example is reduced to 80 nm and both the vertical period
503, and the horizontal period 505 is increased to 400 nm.
[0095] The reduction of the protruded nanometer sized dots 501
diameter is achieved by reducing the inert gas ions dose to less
than 0.05 nC/.mu.m.sup.2 and also reducing the beam current to less
than 0.5 pA.
[0096] The imaging conditions of FIG. 5 are the same as set in FIG.
4 with the scale bar 505 for reference.
[0097] By way of a further exemplary embodiment, further reducing
the inert gas ions dose, for example to 0.03 nC/.mu.m.sup.2 or
less, and also further reducing the beam current to 0.4 pA or less,
the diameter of the protruded nanometer sized dots 601 is reduced
to 50 nm fabricated on single crystal diamond facet 602 as shown in
FIG. 6.
[0098] The array of protruded nanometer sized dots 601 has both the
same vertical period 603 and horizontal period 605 as shown in FIG.
5 with a similar scale bar 604 for reference and comparative
purposes.
[0099] As will be understood and appreciated by those skilled in
the art, the exemplary embodiments as described with reference to
FIG. 4, FIG. 5, and FIG. 6 show that the diameter of protruded
nanometer sized dots can be controlled by appropriately tuning the
incident gas ions dose and the probe current, hence the beam size
of incident gas ions, from diameter of 200 nm shown in FIG. 4, to a
significantly lower size down to 50 nm shown in FIG. 6.
[0100] Furthermore, the change of the both vertical and horizontal
periods in the protruded array of nanometer sized dots from 200 nm
as shown in FIG. 4 to 400 nm as shown in both FIG. 5, and FIG. 6,
indicate that the focused inert gas ion beam has the ability and
efficacy to be utilised to fabricate those protruded nanometer
sized dots at arbitrary positions on a specimen surface as a result
of a protruded mark in a form of a single or array of dot, pillar,
dome, hemisphere, line, irregular shape, symmetric or asymmetric
shape, or arbitrary shape which is in periodic line array, hole/dot
array, circular array, spiral array, fractal array or multiple
periods array, by way of example.
[0101] Reference is made to FIGS. 7a and 7b, in order to further
explain the geometry of the protruded nanometer sized dots, whereby
a schematic graph shows the cross-sections between the surface
profiles of untreated flat specimen surface 702 and the protruded
surface 703 with nanometer sized dots.
[0102] With reference to the Z-direction axis 701, the untreated
flat surface 702 of FIG. 7a is at the level of Z=0 whilst the
protruded surface 703 of FIG. 7b is deformed to the positive sign
of Z-direction, thus having a profile higher than the untreated
flat surface 702.
[0103] Further space upper than the untreated flat surface 702 or
the protruded surface 703 may be exposed to air/vacuum in the
positive sign of Z-direction axis, whilst in the negative side of
Z-direction the specimen depth may be finite or semi-infinite.
[0104] The height 705 of the protruded surface 703 is defined as
being from the displacement of the protruded surface 703 top from
Z=0 while the width or diameter 704 of the protruded surface 703 or
dot is defined as the greatest displacement between two lowest
points in the surface profile of the protruded surface 703 just
above Z=0.
[0105] Referring to FIG. 8, there is shown an example of schematic
three-dimensional contour diagram of a protruded mark 801 profile
so as to provide for enhanced illustration, appreciation and
understanding of the shape of the protruded mark 801 fabricated on
flat surface 802 by focused inert gas ion beam.
[0106] The height of the protruded mark, has the same definition as
705 explained and discussed in reference to FIG. 7b, whereby the
protruded mark 801 extends from the flat surface 802 in reference
to axis 803, while the width and depth have the same definition as
704 as explained and described in reference to FIG. 7a and FIG. 7b,
of the protruded mark 801 are in reference to 804 and 805
respectively.
[0107] In reference to the illustrative example of FIG. 8 to those
protruded nanometer sized dots shown in FIG. 4, FIG. 5 and FIG. 6,
the dimension units of all axes 803, 804 and 805 are in
nanometers.
[0108] Referring to the ion microscope images shown in FIG. 9a and
FIG. 9b, an exemplary embodiment of the invention is shown whereby
the feasibility is demonstrated of fabricating a predetermined and
designed nanometer sized continue pattern or mark 905 on single
crystal diamond facet 902 and 906 by a programmed array 903,
whereby the energetic inert gas ion incident at which is shown as
white dots 901. The displacement between centers of adjacent white
dots 901 is about 120 nm with reference to the scale bar 904.
[0109] By controlling the dose and beam current of the incident
energetic inert gas ions, in order to achieve each protruded
nanometer sized dot having a diameter of not less than 120 nm, a
continued protruded line 905 and further a two-dimensional
protruded pattern or mark 907 on facet 906 with a size of around
800 nm.times.800 nm, with reference to the scale bar 908, instead
of discrete dots has been formed as shown in FIG. 9b.
[0110] Those skilled in the art will appreciate that the present
invention allows for the provision of numerous other and alternate
embodiments utilising the methodology and process of the present
invention, so as to provide marking to a solid state material in a
predetermined manner, for a variety of applications depending upon
the requirements of such applications.
[0111] The present invention provides a method and system for the
application of a marking to a solid state material and a marked
solid state material resulting therefrom, preferably a precious
stone, which provides marking having the advantages including those
of the following: [0112] (i) marking which is not unsightly and
which may not be readily viewed without the knowledge of specific
parameters for the viewing and identification of such marking;
[0113] (ii) marking, which when applied to precious stones or
gemstones, allows for identification for security purposes, as well
as tracking and origin purchases, benefits and advantages in the
precious stone industry; [0114] (iii) security purposes for marking
of solid state materials which may be identified in the event of
impropriety, theft or the like; [0115] (iv) marking of a solid
state material, without the disadvantages associated with
destructive and invasive methods of marking such as etching,
ablation, millings, engravings or the like; [0116] (v) a
methodology and product thereof which does not result in removal of
material or any significant loss in weight or mass of the solid
state material to which the marking is to be applied; [0117] (vi) a
methodology and product thereof which does not alter the optical
properties of a solid state material, and which does not
detrimentally affect the clarity or colour of the solid state
material; [0118] (vii) a methodology and product thereof which
utilises an inert gas, and does not introduce contaminants or
impurities to the solid state material; [0119] (viii) a methodology
and product thereof which obviates the necessity of post-processing
of the solid state material; [0120] (ix) a methodology and product
thereof that requires no significant removal of material from the
surface of solid state material; [0121] (x) a methodology and
product thereof which obviates the necessity of pre-treatment of
coating of the solid state material prior to application of
marking; [0122] (xi) a methodology and product thereof, having no
associated chemical residue; [0123] (xii) a methodology and product
thereof which obviates the necessity of post-processing and the
utilisation of complex post-processing techniques such as chemical
and plasma cleaning and the like.
[0124] By providing a method of marking a surface of solid state
material by applying focused inert gas ion beam local irradiation
in a way of protruding up a top surface of a material to form
patterns or marks, due to expansion of solid state crystalloid
lattice underneath its top surface by the force of inert gas
accumulation or amorphisation of crystalline underneath, instead of
etching, engraving, milling or removing top surface material, which
are concerned as destructive and invasive and ablative to the solid
state material, the present invention provides significant
advantages over those of the prior art.
[0125] Those skilled in the art will appreciate the advantages
associated with such a marking technique and methodology for solid
state material which may be utilised and implemented in other
applications in addition to those as described in the exemplary
embodiments and examples thereof.
[0126] While the present invention has been explained by reference
to the examples or preferred embodiments described above, it will
be appreciated that those are examples to assist understanding of
the present invention and are not meant to be restrictive.
Variations or modifications which are obvious or trivial to persons
skilled in the art, as well as improvements made thereon, should be
considered as equivalents of this invention.
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