U.S. patent application number 11/931230 was filed with the patent office on 2008-10-02 for method and apparatus for fabricating or altering microstructures using local chemical alterations.
Invention is credited to SUPRATIK GUHA, Hendrik F. Hamann, Herschel M. Marchman, Robert J. Von Gutfeld.
Application Number | 20080236745 11/931230 |
Document ID | / |
Family ID | 34550178 |
Filed Date | 2008-10-02 |
United States Patent
Application |
20080236745 |
Kind Code |
A1 |
GUHA; SUPRATIK ; et
al. |
October 2, 2008 |
METHOD AND APPARATUS FOR FABRICATING OR ALTERING MICROSTRUCTURES
USING LOCAL CHEMICAL ALTERATIONS
Abstract
A method and apparatus for fabricating or altering a
microstructure use means for heating to facilitate a local chemical
reaction that forms or alters the submicrostructure.
Inventors: |
GUHA; SUPRATIK; (Chappaqua,
NY) ; Hamann; Hendrik F.; (Yorktown Heights, NY)
; Marchman; Herschel M.; (Poughquag, NY) ; Von
Gutfeld; Robert J.; (New York, NY) |
Correspondence
Address: |
Moser, Patterson & Sheridan, LLP
Suite 100, 595 Shrewsbury Avenue
Shrewsburry
NJ
07702
US
|
Family ID: |
34550178 |
Appl. No.: |
11/931230 |
Filed: |
October 31, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10696771 |
Oct 29, 2003 |
7329361 |
|
|
11931230 |
|
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Current U.S.
Class: |
156/345.11 ;
118/58; 118/715; 156/345.37; 257/E21.251; 257/E21.252; 257/E21.309;
257/E21.31; 257/E21.411; 257/E21.595; 257/E29.297 |
Current CPC
Class: |
H01L 21/31116 20130101;
H01L 21/31111 20130101; H01L 21/32134 20130101; Y10S 977/891
20130101; Y10S 977/855 20130101; Y10S 977/857 20130101; H01L
29/66742 20130101; Y10S 977/89 20130101; Y10S 977/892 20130101;
H01L 29/78684 20130101; H01L 21/32135 20130101; H01L 21/76892
20130101 |
Class at
Publication: |
156/345.11 ;
156/345.37; 118/58; 118/715 |
International
Class: |
C23F 1/08 20060101
C23F001/08; B05C 11/00 20060101 B05C011/00; C23C 16/00 20060101
C23C016/00 |
Claims
1. An apparatus for chemical fabricating or altering a
submicrostructure on an object, comprising: a means for heating a
local region on the object; and a controller for positioning the
heating means proximate to said local region of the object where
the submicrostructure is formed or altered using a local chemical
reaction facilitated by the heating means.
2. The apparatus of claim 1, wherein the local region is provided
with reactants for the chemical reaction.
3. The apparatus of claim 2, wherein the reactants are provided in
at least one of a liquid phase, solid phase and a gaseous phase,
where the liquid phase comprising at least one of a thin layer form
and a droplet form.
4. The apparatus of claim 1, wherein the chemical reaction effects
at least one of etching, depositing, and removing material from the
object.
5. The apparatus of claim 1, wherein the heating means is adapted
to a first end of a cantilever, where said cantilever has a second
end coupled to a device for positioning the heating means.
6. The apparatus of claim 1, wherein the heating means comprises at
least one of a nanoheater and a thermal transducer.
7. The apparatus of claim 6, wherein a heat-emitting surface of the
thermal transducer has topographic dimensions in a range of about
10 to 200 nm.
8. The apparatus of claim 1, wherein a heat-conductive medium is
provided between said heating means and said local region.
9. The apparatus of claim 8, wherein the heat-conductive medium
comprises at least one of a lubricant and a reactant.
10. The apparatus of claim 1, wherein the submicrostructure is a
defect-eliminating feature formed or altered on a portion of a
lithographic reticle or mask.
11. The apparatus of claim 10, wherein the chemical reaction
performs at least one of etching a film in an opaque region,
depositing a film in an opaque region, etching a film in a
transparent region, and depositing a film in said transparent
region.
12. The apparatus of claim 1, wherein the submicrostructure is a
portion of an integrated circuit.
13. The apparatus of claim 12, wherein the portion is at least one
of a line, a conductive via, a contact pad, and a dielectric
pad.
14. The apparatus of claim 1, wherein the submicrostructure is a
portion of a field effect transistor.
15. The apparatus of claim 14, wherein the chemical reaction is at
least one of reactions forming a channel region, forming source and
drain regions, forming a gate dielectric, and forming a gate
electrode.
16. The apparatus of claim 1, wherein the submicrostructure is an
information-containing portion of a recording medium.
17. The apparatus of claim 16, wherein the recording medium
comprises at least one of digital video discs (DVD) and compact
recording (CD-ROM) disks.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 10/696,771, filed Oct. 29, 2003, which is herein
incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to a method and
apparatus for fabricating or altering microstructures. More
specifically, the present invention relates to fabricating or
altering submicrostructures using local chemical alterations
facilitated by a heating means, e.g., a thermal transducer or a
nanoheater.
[0004] 2. Description of the Related Art
[0005] Devices such as integrated circuits, lithographic
reticles/masks, and recording media, among others, comprise various
microstructures that perform critical functions within the device.
Such microstructure are generally formed on substrates (e.g.,
semiconductor or glass substrates, plastic discs, and the like) and
include portions of electronic circuits (e.g., conductive lines,
vias, transistors, insulative layers) and optical circuits, such as
transparent, opaque, and phase-shifting regions of the
reticles/masks, reflective regions of recording media, and the
like.
[0006] Methods used to repair, as well as manufacture the
microstructures exploit a plurality of technologies, such as laser
heating, thermo-mechanical machining, electron and ion beam
machining, along with an array of technologies used in fabrication
of integrated circuits. However, in applications such as making
alterations or repairing defects in lithographic reticles/masks or
integrated circuits, patterning information in recording media, and
the like, these technologies are frequently inefficient or cannot
provide a localized action (i.e., resolution) needed to manufacture
a desired microstructure or correct the defect.
[0007] Therefore, there is a need in the art for an improved method
and apparatus for fabricating or altering microstructures.
SUMMARY OF THE INVENTION
[0008] In one embodiment, the present invention discloses a method
of fabricating or altering microstructures (or submicrostructures
such as nanostructures in one embodiment) using a heating means
such as a thermal transducer or a nanoheater that facilitates a
local chemical reaction to form or alter a nanostructure. Exemplary
applications of the method include forming and altering portions of
integrated circuits and lithographic reticles/masks, patterning
information on recording media, and the like.
[0009] Another aspect of the invention is an apparatus performing
the inventive method.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The teachings of the present invention can be readily
understood by considering the following detailed description in
conjunction with the accompanying drawings, in which:
[0011] FIG. 1 depicts a flow diagram of a method for fabricating or
altering microstructures in accordance with one embodiment of the
present invention;
[0012] FIG. 2 depicts a schematic diagram of an exemplary apparatus
performing the method of FIG. 1;
[0013] FIGS. 3A-3D depict schematic diagrams of various embodiments
of a thermal transducer and nanoheater of the kind that may be used
in the apparatus of FIG. 2;
[0014] FIG. 4 depicts a series of exemplary graphs illustrating
dependence of local temperature distribution and chemical reaction
rate using the nanoheater (means of heating) of FIG. 3D;
[0015] FIG. 5 depicts a flow diagram illustrating embodiments of a
portion of the method of FIG. 1 in various applications of the
present invention;
[0016] FIGS. 6A-6D depict a series of schematic, top plan views of
objects having microstructures being fabricated using the method of
FIG. 1; and
[0017] FIGS. 7A-7F depict a series of schematic, cross-sectional
views of a substrate having a field effect transistor being
fabricated using the method of FIG. 1.
[0018] To facilitate understanding, identical reference numerals
have been used, where possible, to designate identical elements
that are common to the figures.
[0019] It is to be noted, however, that the appended drawings
illustrate only exemplary embodiments of this invention and are
therefore not to be considered limiting of its scope, for the
invention may admit to other equally effective embodiments.
DETAILED DESCRIPTION
[0020] The present invention is a method and apparatus for
fabricating or altering microstructures using a heating means,
e.g., a thermal transducer or a nanoheater that facilitates a local
chemical reaction to form a microstructure. Throughout the present
disclosure, the terms "thermal transducer" and "nanoheater" are
interchangeably used, but it should not be interpreted as limiting
the present invention. However, generally we refer to thermal
transducer where a larger heat spot is reduced via geometrical to a
smaller heat spot while the nanoheater generates a very small heat
spot directly. Herein, the term "microstructure" relates to
portions of devices and integrated circuits that are formed or
repaired using the inventive method. It should also be noted that
the present invention may operate at a very localized region of an
object, to fabricate or alter a "submicrostructure", e.g., a
nanostructure on the object. Thus, by fabricating or altering the
"submicrostructure" of the object, it is understood that a
"microstructure" of the device can be altered or fabricated. The
term "local" relates to a very small region of the object, e.g.,
where a nanostructure being altered or fabricated is less than or
equal to an area of 0.1.times.0.1 micrometer square. Thus, heating
a local region of the object means that a small region of the
object is locally heated such that a chemical reaction may occur to
produce a nanostructure having an approximate area of 0.1.times.0.1
micrometer square or less.
[0021] FIG. 1 depicts a flow diagram for one embodiment of the
inventive method for fabricating microstructures as a method 100.
The method 100 includes the processing steps that are performed
upon an object where at least one microstructure is formed or
altered.
[0022] FIG. 2 depicts a schematic diagram of an exemplary apparatus
200 performing the method of FIG. 1 in accordance with one
embodiment of the invention. The images in FIG. 2 are not depicted
to scale and are simplified for illustrative purposes. To best
understand the invention, the reader should simultaneously refer to
FIG. 1 and FIG. 2.
[0023] The method 100 starts at step 101 and proceeds to step 102.
At step 102, an object 202 (e.g., semiconductor or glass substrate,
plastic disc, and the like) having one or more regions 204 where a
microstructure should be formed (one region 204 is shown) is
provided to the apparatus 200 and positioned on a support pedestal
206, which comprises typically a piezo electric module. In
operation, a system controller 220, in a conventional manner,
controls operation of the apparatus 200.
[0024] At step 104, reactants that can be used to form the desired
microstructure are selectively supplied, at an ambient temperature,
to the region 204 or, alternatively, to a plurality of such
regions. For most applications, a rate of a chemical reaction is
exponentially proportional to the absolute temperature. As such, at
the ambient temperature, the reactants do not react or react at a
very low rate.
[0025] At step 106, means for heating a region 210 is positioned
proximate the region 204. In one embodiment, the means for heating
a region 210 may comprise a thermal transducer or a nanoheater,
which is attached 212 (e.g., an electrical nanoheater) to a
flexible cantilever 214. Such thermal transducers and nanoheaters
are disclosed, for example, in commonly assigned U.S. Pat. No.
6,532,125, issued Mar. 11, 2003, and U.S. Pat. No. 6,433,310,
issued Aug. 13, 2002, which are incorporated herein by reference.
Salient features of the nanoheaters and thermal transducers are
discussed below in reference to FIG. 3, wherein suffixes "a"
through "d" are used to differentiate between various embodiments
of the thermal transducer and nanoheaters. In the depicted
preferred embodiment, the means for heating the region 210
illustratively comprises an electric nanoheater 212d.
[0026] The nanoheater 212d is located near a first end 216 of the
cantilever 214 while second end 224 is coupled to a motion
controller 218 that, in operation, positions the nanoheater 212d
proximate to the region 204. In one embodiment, the motion
controller 218 determines positioning of both the nanoheater 212d
and support pedestal 206. The nanoheater 212d comprises a
heat-emitting surface facing the region 204 and having topographic
dimensions in a range from about 10 to 100 nm.
[0027] At step 108, the means for heating the region 212, e.g., a
nanoheater, is energized (i.e., heated to a pre-determined
temperature) via interface 222 using a power supply 208. By
interface we mean, for example, electrical leads or an optical
fiber, which supplies the power to a thermal transducer or
nanoheater. Typically, the nanoheater 212 is energized using one or
more short pulses of electrical current, radiant energy, and the
like. Generally, the interface 222 is disposed within the
cantilever 214. In an alternative embodiment (not shown), step 108
may be performed prior to step 106.
[0028] At step 110, the nanoheater 212d locally increases
temperature of the reactants disposed proximate to the
heat-emitting surface of the nanoheater (i.e., in the region 204).
The high temperature of the reactants facilitates a local chemical
reaction (discussed in detail below in reference to FIG. 4) between
the reactants that forms, in the region 204, the desired
microstructure. Upon completion of the local chemical reaction, the
power supply 208 terminates energizing the nanoheater 212, and the
motion controller 218 moves the nanoheater away from the region
204.
[0029] At step 112, the method 100 queries if all microstructures
have been formed or altered. If the query of step 112 is negatively
answered, the method 100 proceeds to step 104 to continue
fabrication or alteration of the microstructures on the substrate
202. If the query of step 112 is affirmatively answered, the method
100 proceeds to step 114, where the method 100 ends.
[0030] FIGS. 3A-3D depict schematic diagrams of exemplary
embodiments of the nanoheater 212. The images in FIGS. 3A-3D are
not depicted to scale and are simplified for illustrative purposes.
FIGS. 3A-B are examples for thermal transducer where a larger heat
spot is "concentrated" via geometrical means to a smaller heat
spot. FIGS. 3C-D are examples for nanoheaters, where a small heat
spot is directly generated.
[0031] FIG. 3A depicts a schematic diagram of a laser-powered
thermal transducer 212a comprising a lens 312 that focuses a laser
beam 318 on a thermally conductive plate 314, which could be part
of a cantilever having a nano-tip 316. In operation, the laser beam
318 heats the plate 314 that conducts the heat to the nano-tip 316
disposed proximate the region 204 to facilitate the local chemical
reaction.
[0032] FIG. 3B depicts a schematic diagram of an electrical thermal
transducer 212b comprising a heater element 328 embedded in a
thermally conductive plate 322 and power leads, or transmission
lines, 324. The plate 322 has a nano-tip 326 that operates similar
to the nano-tip 316.
[0033] FIG. 3C depicts a schematic diagram of another electrical
nanoheater 212c comprising a resistive element 338 applied to a
nano-tip 336 of a support 332, as well as transmission lines 334.
The support 332 is formed from a material having low thermal
conductivity to facilitate, in operation, high temperature of the
nano-tip 338 and, as such, high rate of the local chemical
reaction.
[0034] FIG. 3D depicts a schematic diagram of a preferred
electrical nanoheater 212d comprising heater element 342
electrically coupled to transmission lines 344 that, together, form
the interface 222. In one embodiment, the heater element 342 and
transmission lines 344 are embedded in the cantilever 214. In
operation, a heat-emitting surface 346 of the nanoheater is
disposed proximate the region 204. In one embodiment, an optional
thermally conductive medium (e.g., chemically inert lubricant) may
be applied to the heat-emitting surface 346 to increase, in the
region 204, thermal coupling between the heater element 342 and the
reactants. In another embodiment, a "soft contact" (i.e., contact
excerpting no pressure) may be established between the heater
element 342 and substrate 202 to minimize thermal losses in a
conduction pass from the heater element to the region 204. In a
further embodiment, the reactants may be used to form the
conduction pass.
[0035] The following considerations may be used as guidelines when
choosing a material of the heater element 342: (i) it is preferred
to use chemically inert materials (e.g., gold (Au), platinum (Pt),
and the like) and/or apply protective coatings (e.g., silicon
dioxide (SiO.sub.2) to the heat-emitting surface 346, and (ii) the
material should have a high melting point. When the heater element
342 has a direct contact with the substrate 202, use of a "hard"
material (e.g., platinum-iridium (Ptlr) alloy) is advantageous in
order to avoid wear out of the heater element. To minimize
spreading of the heat, a material with low heat conductivity
(.lamda.<100 W/mK), as well as the material with a negative
temperature dependence of the heat conductivity may be chosen.
While low heat conductivity of the heater element is advantageous
for confining the heat, it is less an advantage for heating
efficiently without any loading from the object. In order to
minimize heating of the transmission lines 344, it is preferred
that the resistivity or sheet resistance of the material of the
heater element is large (e.g., >1 .OMEGA. per square). The
heater element may generally be of any kind of shape (e.g., square,
annular, and the like). When the substrate requires heat spots with
a certain shapes, a wave-like shape may be advantageous.
[0036] To minimize spreading of the heat in the nanoheater 212d,
the transmission lines 344 should have high electrical conductivity
and large cross-sectional area, as well as, preferably, low thermal
conductivity. It is preferred that the transmission lines do not
protrude through a lower surface 348 of the cantilever 214. The
choice of a material of the cantilever 214 may be guided by the
Young's modulus of the material, which along with other parameters
(e.g., dimensions and shape), determine a spring constant of the
cantilever, as well as by thermal conductivity of the material.
Spring constants can vary from 0.0001 N/m to 1000 N/m depending on
a surface hardness of the heater element 342 and substrate 202.
Generally, materials with high thermal conductivity are preferred.
One suitable material for the cantilever 214 may be intrinsic
silicon (Si).
[0037] FIG. 4 depicts an exemplary graph 400 that illustrates
dependence of a calculated normalized steady state temperature
(y-axis 402) and a normalized chemical reaction rate (y-axis 404)
from a distance (x-axis 406) from a center of the nanoheater 212d.
In this calculation an approximate "semi-infinite" object is
assumed. In one embodiment, the nanoheater 212d has a 20 nm square
heat-emitting surface 346 that is in a "soft" contact with the
substrate 202. In the depicted embodiment, the attained temperature
in the center (i.e., at the distance "0") of the region 204 is
about 300 degrees Celsius (e.g., it is normalized--temperature will
scale with power deposited from the nanoheater on the
substrate--the resulting temperature will depend (to a first order)
on thermal conductivity of object) and a width 410 (e.g., the width
bar is not at the 50% level) of the temperature distribution at 50%
of a peak 408 is about 56 nm. In this embodiment, a width of the
distribution of a reaction rate for a chemical reaction having a 50
kJ/mol activation barrier is about 20 nm, or, approximately, three
times narrower than the width 410 of the temperature distribution
of the region 204. For comparison, at optical frequencies, a
minimal width of the focusing spot of a laser beam is about 300 nm,
or about 5-6 times greater than the width 410.
[0038] In exemplary embodiments discussed below, the method 100 is
used to perform local chemical alterations and form microstructures
using various etch and deposition processes. The fabricated
microstructures include portions of integrated circuits and field
effect transistors, defect-eliminating features, and information
patterns written on recording media, among other
microstructures.
[0039] FIG. 5 depicts optional sub-steps 104A-104D that may be a
part of step 104 in the exemplary embodiments of the method 100.
Specifically, reactants for the local chemical reactions may be
provided in a liquid phase (sub-step 104A) or in a gaseous phase
(sub-step 104B) or a solid phase (not shown). Liquid phase
reactants may be deposited on the substrate 202 in a form of a thin
layer (sub-step 104C) covering a substantial portion of the
substrate surface (e.g., entire substrate surface). Alternatively,
liquid reactants may be deposited in the form of droplets (sub-step
104D) which are substantially limited to the regions 204 of the
substrate. In a further embodiment, depending on a specific
application of the method 100, the reactants may be provided using
any combination of sub-steps 104A-104D, e.g., some reactants may be
provided in the liquid phase, while at least one reactant is
provided in the gaseous phase.
[0040] FIGS. 6A-6D depict a series of exemplary applications of the
method 100 for fabricating defect-eliminating microstructures
and/or repairing lithographic reticles/masks and integrated
circuits. Depending on a specific chemical composition of the
reactants, the method 100 can facilitate at least one of localized
deposition and etch reactions. In these embodiments, the reactants
are illustratively applied in a liquid phase and in the form of a
thin layer over a surface area 610 that is substantially greater
that the region 204 of the substrate 202 (discussed above in
reference to FIG. 2). FIGS. 6A and 6C depict a state of the
localized deposition and etch chemical reactions, respectively,
prior to energizing the nanoheater (means for heating) 212 (e.g.,
nanoheater 212d). Accordingly, FIGS. 6B and 6D depict the results
of the corresponding reactions when facilitated by the nanoheater
212d (shown after the remaining reactants have been removed). The
images in FIGS. 6A-6D are not depicted to scale and are simplified
for illustrative purposes.
[0041] FIG. 6A depicts the substrate 202 illustratively comprising
lines 602 and 604 that should be interconnected. As such, the
reactants are selected such that, when react at high temperature
produced by the nanoheater 212d, can form a desired interconnecting
material (e.g., same material as that of the lines 602 or 604). In
a further embodiment, the region 204 may include a contact hole
(i.e., via) or a contact pad, as well as lines 602 and 604 may each
be a portion of various devices of the integrated circuit or
lithographic reticle. For example, when the lines 602 and 604 are
formed from Aluminum, the reactants may comprise,
triethyl-aluminum.
[0042] FIG. 6B depicts a microstructure 606 interconnecting the
lines 602 and 604 of the kind that may be formed using the
localized chemical reaction. To heat the reactants to the high
temperature facilitating such a reaction, the nanoheater 212 may be
energized using one or more short pulses of an electric current.
Depending on the application, the microstructure 606 may be either
a defect-eliminating feature (e.g., a missing or erroneously burned
jumper) or a new feature of the integrated circuit or lithographic
reticle/mask. As discussed above, beyond the region 204, the rate
of the same chemical reaction in negligible.
[0043] FIG. 6C depicts an alternative embodiment when a line 612 is
a solid conductive line that should be interrupted, or opened. In
this embodiment, the reactants are selected such that, when react
at high temperature produced by the nanoheater 212, can remove
(i.e., etch) the material of the line 612. In a further embodiment,
the line 612 may be formed from a dielectric material, such as an
optically transparent phase-shifting portion of a lithographic
reticle, a dielectric pad of a capacitor, and the like.
[0044] FIG. 6D depicts a result of the localized chemical reaction
of the kind that may etch and remove the material of the line 612
in the region 204 heated by the means for heating, e.g., a
nanoheater, 212, thus forming a gap 614 between portions 612A and
612B of the line 612. Similar to the embodiment of FIGS. 6A-6B,
beyond the region 204, the rate of the same chemical reaction in
negligible. The gap 614 may be considered as a defect-eliminating
feature (e.g., when the line 612 was erroneously formed as the
solid line) or a new feature (e.g., programming feature) of the
integrated circuit or an opaque region of the lithographic reticle.
Defects having topographic dimensions less than the region 204
(e.g., metallic droplets in a transparent portion of the
lithographic reticles/masks) may also be removed using the same
localized etch reaction. In another application, localized etch
reaction may be used to etch or decompose low-k dielectrics,
prepare samples for focused ion beam (FIB) and scanning electron
microscope (SEM) analysis, and the like.
[0045] FIGS. 7A-7F illustrate an exemplary application of the
method 100 during fabricating of a field effect transistor (FET)
using a sequence of localized chemical vapor deposition (CVD)
processes that use gaseous phase reactants. During such a CVD
process, precursors are absorbed on exposed surfaces. In this
application, local decomposition of the precursors by means of
pyrolysis is initiated in the heat spot (i.e., region 204)
generated by the means for heating the object 210. At least one of
the products of the CVD gas becomes a solid and remains on a
surface of the substrate after such local heat treatment. The
precursor gas could be changed and different materials may be
deposited to build electronic circuits. For example, a gaseous
precursor containing a copper compound can be used to trace out
patterns of missing or broken copper circuit lines on a chip with a
resolution previously not possible by presently known techniques.
Such chemical alterations of both metals and insulators may be
performed without use of a mask, which is an advantage of the
invention. The images in FIGS. 7A-7F are not depicted to scale and
are conventionally simplified for illustrative purposes.
[0046] FIG. 7A depicts a substrate 702 (e.g., silicon (Si) wafer)
having a silicon dioxide (SiO.sub.2) layer 704 where a seed
germanium (Ge) layer 706 is formed using non-selective Ge chemistry
and a localized CVD process facilitated by the means for heating
the object, e.g., a nanoheater 212d.
[0047] FIG. 7B depicts the substrate 702 after the Ge layer 708
(i.e., channel region) has been grown, from the seed layer, in the
heat spot of the nanoheater 212d using selective Ge chemistry and
the localized CVD process.
[0048] FIG. 7C depicts the substrate 702 after source and drain
regions 710 of the transistor have been sequentially formed, in a
heat spot of the nanoheater 212d, using selective chemistry and the
localized CVD process.
[0049] FIG. 7D depicts the substrate 702 after metal contacts 712
(e.g., gold (Au), and the like) have been sequentially formed, in a
heat spot of the nanoheater 212d, using the localized CVD
process.
[0050] FIGS. 7E and 7F depict the substrate 702 after a gate
dielectric 714 (e.g., GeO.sub.2) and a gate electrode 716 (e.g.,
Au) have been formed using the respective conventional CVD
processes.
[0051] In yet another application, the method 100 may be used to
form an information-containing portion of recording media, e.g.,
write information on digital video (DVD) discs and compact "read
only" (CD-ROM) disks. Such disks may use Polymethyl metacrylrate
(PMMA) material that is spun over a surface of the disc. The means
for heating the object can initialize a free radical vinyl
polymerization process to form locally the PMMA-plastic material. A
radical starter may further be used to enhance the process. The
unreacted (i.e., unheated) regions are washed off to complete
fabrication of a PMMA mask. Such a mask may be used in a servo loop
during patterning optical disk drives.
[0052] In still another application, the method 100 may be used to
facilitate and enhance a broad range of localized biochemical
reactions, e.g., protein-related reactions.
[0053] While the foregoing is directed to the illustrative
embodiment of the present invention, other and further embodiments
of the invention may be devised without departing from the basic
scope thereof, and the scope thereof is determined by the claims
that follow.
* * * * *