U.S. patent application number 10/902643 was filed with the patent office on 2005-03-17 for apparatus and method for treating surfaces of semiconductor wafers using ozone.
Invention is credited to Jeong, In Kwon, Kim, Jungyup, Kim, Yong Bae.
Application Number | 20050056306 10/902643 |
Document ID | / |
Family ID | 32770266 |
Filed Date | 2005-03-17 |
United States Patent
Application |
20050056306 |
Kind Code |
A1 |
Jeong, In Kwon ; et
al. |
March 17, 2005 |
Apparatus and method for treating surfaces of semiconductor wafers
using ozone
Abstract
An apparatus and method for treating surfaces of semiconductor
wafers with a reactive gas, such as ozone, utilizes streams of
gaseous material ejected from a gas nozzle structure to create
depressions on or holes through a boundary layer of processing
fluid formed on a semiconductor wafer surface to increase the
amount of reactive gas that reaches the wafer surface through the
boundary layer. The apparatus and method may be used to clean a
semiconductor wafer surface and/or grow an oxide layer on the wafer
surface by oxidation.
Inventors: |
Jeong, In Kwon; (Cupertino,
CA) ; Kim, Yong Bae; (Cupertino, CA) ; Kim,
Jungyup; (San Jose, CA) |
Correspondence
Address: |
WILSON & HAM
PMB: 348
2530 Berryessa Road
San Jose
CA
95132
US
|
Family ID: |
32770266 |
Appl. No.: |
10/902643 |
Filed: |
July 29, 2004 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10902643 |
Jul 29, 2004 |
|
|
|
10350739 |
Jan 23, 2003 |
|
|
|
10350739 |
Jan 23, 2003 |
|
|
|
10282562 |
Oct 29, 2002 |
|
|
|
Current U.S.
Class: |
134/94.1 ;
134/137; 134/151; 134/172; 134/198; 134/37 |
Current CPC
Class: |
H01L 21/02046 20130101;
H01L 21/67051 20130101; B08B 2203/005 20130101; H01L 21/31662
20130101; B08B 3/02 20130101; B08B 3/08 20130101; H01L 21/02238
20130101 |
Class at
Publication: |
134/094.1 ;
134/037; 134/137; 134/151; 134/172; 134/198 |
International
Class: |
B08B 007/04; B08B
003/00 |
Claims
What is claimed is:
1. An apparatus for treating a surface of an object with a reactive
gas comprising: an object holding structure configured to hold said
object; a rotational drive mechanism connected to the object
holding structure to rotate the object holding structure and said
object; a fluid dispensing structure positioned relative to said
object holding structure to dispense a processing fluid onto said
surface of said object, said processing fluid forming a fluid layer
on said surface; and a gas nozzle structure positioned relative to
said object holding structure to eject multiple streams of gaseous
material onto said fluid layer formed on said surface of said
object at different locations on said fluid layer, said gas nozzle
structure being configured to introduce said reactive gas to reach
and react with said surface of said object.
2. The apparatus of claim 1 further comprising a pressure
controlling device operatively connected to said gas nozzle
structure to control pressure of said multiple streams of gaseous
material.
3. The apparatus of claim 2 wherein said pressure controlling
device is configured to adjust said pressure of said multiple
streams of gaseous material such that depressions are made on said
fluid layer by said multiple streams of gaseous material to control
thickness of said fluid layer at said depressions.
4. The apparatus of claim 2 wherein said pressure controlling
device is configured to adjust said pressure of said multiple
streams of gaseous material such that holes through said fluid
layer are made by said multiple streams of gaseous material.
5. The apparatus of claim 1 wherein said gaseous material includes
said reactive gas.
6. The apparatus of claim 1 wherein said gas nozzle structure
includes an elongated gas opening to eject a wall-like stream of
gaseous material onto said processing fluid layer.
7. The apparatus of claim 1 wherein said gas nozzle structure
includes multiple openings, said gas nozzle structure being
configured to eject at least one stream of inert gas from said
multiple openings and at least one stream of reactive gas from said
multiple openings.
8. The apparatus of claim 1 wherein said fluid dispensing structure
is configured to dispense said processing fluid in the form of a
spray onto said surface of said object.
9. The apparatus of claim 1 wherein said fluid dispensing structure
is configured to dispense said processing fluid in the form of a
fog onto said surface of said object.
10. The apparatus of claim 9 wherein said fluid dispensing
structure includes an acoustic transducer to generate said fog of
said processing fluid using sonic energy.
11. The apparatus of claim 1 wherein said gas nozzle structure is
shaped in a bar-like configuration.
12. The apparatus of claim 1 wherein said gas nozzle structure
includes a grid-like portion with a plurality of spaces, said
spaces of said grid-like portion allowing said processing fluid
dispensed from said fluid dispensing structure to pass through said
gas nozzle structure.
13. The apparatus of claim 1 wherein said gas nozzle structure is
shaped in a triangular configuration.
14. An apparatus for treating a surface of an object with a
reactive gas comprising: an object holding structure configured to
hold said object; a rotational drive mechanism connected to the
object holding structure to rotate the object holding structure and
said object; a fluid dispensing structure positioned relative to
said object holding structure to dispense a processing fluid onto
said surface of said object, said processing fluid forming a fluid
layer on said surface; and a gas nozzle structure including an
elongated gas opening, said gas nozzle structure being positioned
relative to said object holding structure to eject a wall-like
stream of gaseous material from said elongated gas opening onto
said fluid layer formed on said surface of said object, said gas
nozzle structure being configured to introduce said reactive gas to
reach and react with said surface of said object.
15. The apparatus of claim 14 further comprising a pressure
controlling device operatively connected to said gas nozzle
structure to control pressure of said wall-like stream of gaseous
material from said elongated gas opening of said gas nozzle
structure.
16. The apparatus of claim 15 wherein said pressure controlling
device is configured to adjust said pressure of said wall-like
stream of gaseous material such that a depression is made on said
fluid layer by said wall-like stream of gaseous material to control
thickness of said fluid layer at said depression.
17. The apparatus of claim 15 wherein said pressure controlling
device is configured to adjust said pressure of said wall-like
stream of gaseous material such that said wall-like stream of
gaseous material directly contact said surface of said object
through said fluid layer.
18. The apparatus of claim 14 wherein said gaseous material
includes said reactive gas.
19. The apparatus of claim 14 wherein said gas nozzle structure is
configured to eject one of a wall-like stream of inert gas and a
wall-like stream of reactive gas from said elongated gas
opening.
20. The apparatus of claim 19 wherein said gas nozzle structure
includes at least one additional gas opening to eject one of a
stream of inert gas and a stream of reactive gas.
21. The apparatus of claim 14 wherein said fluid dispensing
structure is configured to dispense said processing fluid in the
form of a spray onto said surface of said object.
22. The apparatus of claim 14 wherein said fluid dispensing
structure is configured to dispense said processing fluid in the
form of a fog onto said surface of said object.
23. The apparatus of claim 22 wherein said fluid dispensing
structure includes an acoustic transducer to generate said fog of
said processing fluid using sonic energy.
24. The apparatus of claim 14 wherein said gas nozzle structure is
shaped in a bar-like configuration.
25. The apparatus of claim 14 wherein said gas nozzle structure is
shaped in a triangular configuration.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application is a division of application Ser.
No. 10/350,739 filed on Jan. 23, 2003, which is a
continuation-in-part of prior application Ser. No. 10/282,562 filed
on Oct. 29, 2002.
FIELD OF THE INVENTION
[0002] The invention relates generally to semiconductor fabrication
processing, and more particularly to an apparatus and method for
treating surfaces of semiconductor wafers using ozone.
BACKGROUND OF THE INVENTION
[0003] Recently, the use of ozone has attracted much attention in
the semiconductor fabrication industry. Ozone has been found to be
effective in cleaning a surface of a semiconductor wafer by
oxidizing undesirable organic and/or metallic materials, such as
photoresist residue, which can then be removed from the wafer
surface. Depending on the cleaning process, a layer of oxide may be
formed on the cleaned surface of the semiconductor wafer as a
result of the cleaning process. Such a layer of oxide is commonly
referred to as a native oxide layer. In addition to cleaning, ozone
has been found to be similarly effective in simply growing a layer
of oxide on a desired surface of a semiconductor wafer. The grown
oxide layers, including native oxide layers, may be used as
passivation or interfacial layers for semiconductor devices.
[0004] Ozone can be applied to a surface of a semiconductor wafer
using a dry or wet technique. Dry ozone application techniques
involve exposing a surface of a semiconductor wafer to ozone gas,
alone or with one or more gases, to oxidize the materials on the
wafer surface. Wet ozone application techniques involve exposing a
surface of a semiconductor wafer to both ozone and a processing
fluid, such as deionized (DI) water or a chemical solution. Such
wet ozone application techniques have been found to be highly
effective in promoting oxidization. One wet ozone application
technique involves dispensing a processing fluid onto a surface of
the semiconductor wafer, which is in a closed processing chamber,
and introducing ozone gas into the closed processing chamber. The
dispensed processing fluid on the surface of the semiconductor
wafer forms a layer of processing fluid on the wafer surface. When
the ozone gas is introduced into the closed processing chamber, the
ozone gas reaches the surface of the semiconductor wafer by
diffusing through the processing fluid layer to oxidize materials
on the wafer surface. Another wet ozone application technique
involves immersing a semiconductor wafer in a bath of processing
fluid with dissolved ozone gas. Thus, the surface of the
semiconductor wafer is exposed to both the ozone and the processing
fluid. Still another technique involves dispensing a processing
fluid with dissolved ozone gas onto a surface of a semiconductor
wafer to expose the wafer surface to both the ozone and the
processing fluid.
[0005] A concern with the above-described wet ozone application
techniques is that the rate of oxidation is relatively low due to a
number of factors. One factor is that the concentration of ozone in
a typical processing fluid is very low. For example, the
concentration of ozone in DI water is roughly 2-40 ppm at room
temperature. Another factor is that ozone decays in processing
fluids, such as DI water and NH.sub.4OH solution. The ozone decay
rate depends on the temperature of the processing fluid and the
chemicals included in the processing fluid. Consequently, the use
of heated processing fluid and/or processing fluid having certain
chemicals may not be practical, although such processing fluid may
be preferred, due to the high ozone decay rate, which significantly
reduces the concentration of ozone applied to the wafer
surface.
[0006] In view of these concerns, there is a need for an apparatus
and method for treating a surface of a semiconductor wafer with
both a desired processing fluid and ozone such that a high
concentration of ozone can be applied to the wafer surface to
effectively oxidize materials on the wafer surface to clean and/or
grow an oxide layer on the wafer surface.
SUMMARY OF THE INVENTION
[0007] An apparatus and method for treating surfaces of
semiconductor wafers with a reactive gas, such as ozone, utilizes
streams of gaseous material ejected from a gas nozzle structure to
create depressions on or holes through a boundary layer of
processing fluid formed on a semiconductor wafer surface to
increase the amount of reactive gas that reaches the wafer surface
through the boundary layer. The depressions that are created by the
streams of gaseous material reduce the thickness of the boundary
layer at the depressions, which allows an increased amount of
reactive gas to reach the wafer surface through the boundary layer
by diffusion. Alternatively, the holes that are created by the
streams of gaseous material allow the reactive gas to directly
contact the wafer surface through the boundary layer, which results
in an increased amount of reactive gas that reaches the wafer
surface. The reactive gas can be introduced by including the
reactive gas as part of the streams of gaseous material.
Alternatively, the reactive gas can be introduced by ejecting the
reactive gas as one or more separate streams of reactive gas. As an
example, streams of ozone gas can be used so that an increased
amount of ozone can reach the semiconductor wafer surface to clean
the wafer surface and/or grow an oxide layer on the wafer surface
by oxidation.
[0008] An apparatus for treating a surface of an object with a
reactive gas in accordance with an embodiment of the invention
includes an object holding structure, a rotational drive mechanism,
a fluid dispensing structure and a gas nozzle structure. The object
holding structure is configured to hold the object. The rotational
drive mechanism is connected to the object holding structure to
rotate the object holding structure and the object. The fluid
dispensing structure is positioned relative to the object holding
structure to dispense a processing fluid onto the surface of the
object, forming a layer of processing fluid on the object surface.
The gas nozzle structure is also positioned relative to the object
holding structure to eject multiple streams of gaseous material
onto the layer of processing fluid formed on the object surface at
different locations on the layer of processing fluid. The gas
nozzle structure is also configured to introduce a reactive gas to
reach and react with the surface of the object.
[0009] An apparatus for treating a surface of an object with a
reactive gas in accordance with another embodiment of the invention
includes an object holding structure, a rotational drive mechanism,
a fluid dispensing structure and a gas nozzle structure. The object
holding structure is configured to hold the object. The rotational
drive mechanism is connected to the object holding structure to
rotate the object holding structure and the object. The fluid
dispensing structure is positioned relative to the object holding
structure to dispense a processing fluid onto the surface of the
object, forming a layer of processing fluid on the object surface.
The gas nozzle structure includes an elongated gas opening to eject
a wall-like stream of gaseous material. The gas nozzle structure is
positioned relative to the object holding structure to eject the
wall-like stream of gaseous material onto the layer of processing
fluid formed on the object surface. The gas nozzle structure is
also configured to introduce the reactive gas to reach and react
with the surface of the object.
[0010] A method for treating a surface of an object with a reactive
gas in accordance with an embodiment of the invention includes
forming a processing fluid layer on the object surface and ejecting
at least one stream of gaseous material through the processing
fluid layer onto the wafer surface to expose a portion of the
object surface. The method also includes introducing the reactive
gas to the exposed portion of the object surface to allow the
reactive gas to react with the object surface.
[0011] A method for treating a surface of an object with a reactive
gas in accordance with another embodiment of the invention includes
forming a processing fluid layer on the object surface and ejecting
multiple streams of gaseous material onto the processing fluid
layer to form multiple depressions on the processing fluid layer.
The method also includes introducing the reactive gas to the
multiple depressions to allow the reactive gas to reach and react
with the object surface.
[0012] A method for treating a surface of an object with a reactive
gas in accordance with still another embodiment of the invention
includes forming a processing fluid layer on the object surface and
ejecting a wall-like stream of gaseous material onto the processing
fluid layer on the object surface. The method also includes
introducing the reactive gas to allow the reactive gas to reach and
react with the object surface.
[0013] Other aspects and advantages of the present invention will
become apparent from the following detailed description, taken in
conjunction with the accompanying drawings, illustrated by way of
example of the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a diagram of an apparatus for treating a surface
of a semiconductor wafer in accordance with a first embodiment of
the present invention.
[0015] FIG. 2 is a top view of the single-wafer spin-type
processing unit of the apparatus of FIG. 1.
[0016] FIG. 3 is a perspective view of the gas nozzle structure of
the single-wafer spin-type processing unit of FIG. 2.
[0017] FIG. 4 is a flow diagram of an overall operation of the
apparatus of FIG. 1.
[0018] FIG. 5 is an illustration showing depressions that are made
on the boundary layer by streams of gaseous material ejected from
the gas nozzle structure of the single-wafer spin-type processing
unit of FIG. 2.
[0019] FIG. 6 is an illustration showing holes that are made
through the boundary layer by streams of gaseous material ejected
from the gas nozzle structure of the single-wafer spin-type
processing unit of FIG. 2.
[0020] FIG. 7 is a perspective view of a single-wafer spin-type
processing unit in accordance with a first alternative embodiment
of the invention.
[0021] FIG. 8 is a top view of a single-wafer spin-type processing
unit in accordance with a second alternative embodiment of the
invention.
[0022] FIG. 9 is a sectional bottom view of the bar-type gas nozzle
structure of the single-wafer spin-type processing unit of FIG.
8.
[0023] FIG. 10 is a top view of a single-wafer spin-type processing
unit in accordance with a third alternative embodiment of the
invention.
[0024] FIG. 11 is a sectional bottom view of the grid-type gas
nozzle structure of the single-wafer spin-type processing unit of
FIG. 10.
[0025] FIG. 12 is a top view of a single-wafer spin-type processing
unit in accordance with a fourth alternative embodiment of the
invention.
[0026] FIG. 13 is a bottom view of the bar-type gas nozzle
structure of the single-wafer spin-type processing unit of FIG.
12.
[0027] FIG. 14 is a top view of a single-wafer spin-type processing
unit in accordance with a fifth alternative embodiment of the
invention.
[0028] FIG. 15 is a bottom view of the triangular gas nozzle
structure of the single-wafer spin-type processing unit of FIG.
14.
[0029] FIG. 16 illustrates a passivation oxide layer formed over
patterned structures using an apparatus in accordance with the
invention.
[0030] FIG. 17 illustrates an interfacial oxide layer formed
between an electrode region and an electrode connector of a
transistor using an apparatus in accordance with an invention.
[0031] FIG. 18 is a diagram of an apparatus for treating a surface
of a semiconductor wafer in accordance with a second embodiment of
the present invention.
[0032] FIG. 19 is a perspective view of a gas nozzle structure,
which may be included in the apparatus of FIG. 18.
[0033] FIG. 20 is an illustration showing a hole that is made
through a boundary layer by a stream of inert gas and a stream of
reactive gas ejected from the gas nozzle structure of FIG. 19.
[0034] FIG. 21 is a bottom view of a bar-type gas nozzle structure,
which may be included in the apparatus of FIG. 18.
[0035] FIG. 22 is a bottom view of a modified triangular gas nozzle
structure in accordance with one configuration, which may be
included in the apparatus of FIG. 18.
[0036] FIG. 23 is a bottom view of a modified triangular gas nozzle
structure in accordance with another configuration, which may be
included in the apparatus of FIG. 18.
[0037] FIG. 24 is a process flow diagram of a method for treating a
surface of a semiconductor wafer with a reactive gas in accordance
with an embodiment of the invention.
[0038] FIG. 25 is a process flow diagram of a method for treating a
surface of a semiconductor wafer with a reactive gas in accordance
with another embodiment of the invention.
[0039] FIG. 26 is a process flow diagram of a method for treating a
surface of a semiconductor wafer with a reactive gas in accordance
with still another embodiment of the invention.
DETAILED DESCRIPTION
[0040] With reference to FIG. 1, an apparatus 100 for treating a
surface 102 of a semiconductor wafer W using a processing fluid in
conjunction with a reactive gaseous agent, such as ozone gas, to
cause a desired reaction of materials on the wafer surface, such as
oxidation, in accordance with a first embodiment of the invention
is shown. Thus, the apparatus 100 can be used to remove oxidizable
materials on the wafer surface and/or to form an oxide layer on the
wafer surface, which may be used as a passivation or interfacial
layer for a semiconductor device. The apparatus 100 uses streams of
reactive gaseous agent ejected from a gas nozzle structure 104 to
increase the amount of reactive gaseous agent to reach the
semiconductor wafer surface through a boundary layer of processing
fluid formed on the wafer surface. As described in more detail
below, the amount of reactive gaseous agent to reach the
semiconductor wafer surface is increased either by creating
depressions at different locations on the boundary layer to reduce
the thickness of the boundary layer at the different locations or
by creating holes through the boundary layer to directly contact
the wafer surface with the reactive gaseous agent using the
pressure of the streams of reactive gaseous agent. The increased
amount of reactive gaseous agent to reach the semiconductor wafer
surface results in more effective treatment of the wafer surface
due to increased reaction with the reactive gaseous agent, which
allows the cleaning of the semiconductor wafer surface and/or
growing of an oxide layer on the wafer surface to be performed more
efficiently.
[0041] As shown in FIG. 1, the apparatus 100 includes a
single-wafer spin-type processing unit 106, a controller 108, a gas
pressure controlling device 110, a fluid mixer/selector 112, an
ozone generator 114, valves 116, 118 and 120, a pump 122, a supply
of fluids 124, and a supply of gases 126. The fluid supply 124
includes containers 128, 130, 132 and 134 to store different types
of fluids, which are used by the single-wafer spin-type processing
unit 106, as described below. Although the fluid supply 124 is
shown in FIG. 1 to include four containers, the fluid supply may
include fewer or more containers. The containers 128, 130, 132 and
134 may include any of the following fluids: de-ionized water,
diluted HF, mixture of NH.sub.4OH and H.sub.2O, standard clean 1 or
"SC1" (mixture of NH.sub.4OH, H.sub.2O.sub.2 and H.sub.2O),
standard clean 2 or "SC2" (mixture of HCl, H.sub.2O.sub.2 and
H.sub.2O), ozonated water (de-ionized water with dissolved ozone),
known cleaning solvents (e.g., a hydroxyl amine based solvent
EKC265, available from EKC technology, Inc.), and any constituent
of these fluids. The types of fluids stored in the containers of
the fluid supply can vary depending on the particular process to be
performed by the apparatus 100.
[0042] Similarly, the gas supply 126 includes containers 136 and
138 to store different types of gases, which are also used by the
single-wafer spin-type processing unit 106, as described below.
Although the gas supply 126 is shown in FIG. 1 to include two
containers, the gas supply may include fewer or more containers.
The gases stored in the containers may include base gases to
generate reactive gaseous agents that react with oxidizable
material, such as photoresist residue and silicon-based material,
on the semiconductor wafer surface 102 to facilitate cleaning of
the wafer surface and/or growing of an oxide layer on the wafer
surface. As an example, one of the containers 136 and 138 may store
oxygen (O.sub.2), which is used by the ozone generator 114 to
generate ozone. The generated ozone can then be applied to the
semiconductor wafer surface 102 to oxidize materials on the wafer
surface, such as residual photoresist. Other gases that may be
stored in the containers include gases that are commonly used in
conventional single-wafer, spin-type, wet-cleaning apparatuses,
such as N.sub.2, or any gas that can be used in wafer processing,
including HF vaporized gas and isopropyl alcohol (IPA) vaporized
gas.
[0043] The single-wafer spin-type processing unit 106 includes a
processing chamber 140, which provides an enclosed environment for
processing a single semiconductor wafer, e.g., the semiconductor
wafer W. The processing unit further includes a wafer support
structure 142, a motor 144, the gas nozzle structure 104, a fluid
dispensing structure 146, mechanical arms 148 and 150, and drive
mechanisms 152 and 154. The wafer support structure 142 is
configured to securely hold the semiconductor wafer for processing.
The wafer support structure 142 is connected to the motor 144,
which can be any rotational drive mechanism that provides
rotational motion for the wafer support structure. Since the
semiconductor wafer is held by the wafer support structure, the
rotation of the wafer support structure also rotates the
semiconductor wafer. The wafer support structure can be any wafer
support structure that can securely hold a semiconductor wafer and
rotate the wafer, such as conventional wafer support structures
that are currently used in commercially available single-wafer,
spin-type, wet-cleaning apparatuses.
[0044] The fluid dispensing structure 146 of the single-wafer
spin-type processing unit 106 is configured to dispense a
processing fluid onto the surface 102 of the semiconductor wafer W,
which forms a boundary layer of processing fluid on the wafer
surface. This boundary layer is just a layer of fluid formed on the
wafer surface by the dispensed processing fluid, such as deionized
water. The processing fluid may be one of the fluids stored in the
containers 128, 130, 132 and 134 of the fluid supply 124.
Alternatively, the processing fluid may be a solution formed by
combining two or more of the fluids from the fluid supply. The
fluid dispensing structure includes one or more openings (not
shown) to dispense the processing fluid onto the semiconductor
wafer surface. The fluid dispensing structure is attached to the
mechanical arm 150, which is connected to the drive mechanism 154.
As illustrated in FIG. 2, which is a top view of the single-wafer
spin-type processing unit 106, the drive mechanism 154 is designed
to pivot the mechanical arm 150 about an axis 202 to move the fluid
dispensing structure 146 laterally or radially across the
semiconductor wafer surface. The lateral movement of the fluid
dispensing structure allows the processing fluid dispensed from the
fluid dispensing structure to be applied to different areas of the
semiconductor wafer surface. Preferably, the semiconductor wafer is
rotated by the motor 144 as the fluid dispensing structure is
laterally moved across the semiconductor wafer surface so that the
applied processing fluid can be distributed over the entire wafer
surface. The drive mechanism 154 may be further configured to
manipulate the mechanical arm 150 so that the fluid dispensing
structure can be moved in any number of different possible
directions, including the vertical direction to adjust the distance
between the fluid dispensing structure and the semiconductor wafer
surface.
[0045] As shown in FIG. 1, the fluid dispensing structure 146 is
connected to the fluid mixer/selector 112 to receive a processing
fluid to be applied to the semiconductor wafer surface 102. The
fluid mixer/selector operates to provide a processing fluid to the
fluid dispensing structure by routing a selected fluid from one of
the containers 128, 130, 132 and 134 of the fluid supply 124 or by
combining two or more fluids from the containers of the fluid
supply to produce the processing fluid, which is then transmitted
to the fluid dispensing structure. The fluid mixer/selector is
connected to each container of the fluid supply via the pump 122,
which operates to pump the fluids from the containers of the fluid
supply to the fluid mixer/selector.
[0046] The gas nozzle structure 104 of the single-wafer spin-type
processing unit 106 is configured to eject streams of gaseous
material onto the surface of the semiconductor wafer W. The gaseous
material may be a single gas, such as ozone, or a combination of
gasses. As illustrated in FIG. 3, which is a perspective view, the
exemplary gas nozzle structure has a substantially planer bottom
surface 302 with a number of small openings 304 for ejecting the
streams of gaseous material. The gas nozzle structure is shown in
FIG. 3 as being circular in shape. However, the gas nozzle
structure may be configured in other shapes, such as a rectangular
shape. The gas nozzle structure may be used during processing of
the semiconductor wafer to eject streams of reactive gaseous agent
onto the boundary layer of processing fluid formed on the
semiconductor wafer surface so that the reactive gaseous agent can
react with oxidizable material on the semiconductor wafer surface.
In addition, the gas nozzle structure may be used to eject streams
of gaseous material, such as IPA vaporized gas, onto the
semiconductor wafer surface to dry the wafer surface after the
semiconductor wafer has been treated with the processing fluid and
ozone and/or rinsed with deionized water.
[0047] Similar to the fluid dispensing structure 146, the gas
nozzle structure 104 is attached to the mechanical arm 148, which
is connected to the drive mechanism 152. The drive mechanism 152 is
designed to pivot the mechanical arm 148 about an axis 204 to move
the gas nozzle structure laterally or radially across the
semiconductor wafer surface 102, as illustrated in FIG. 2. The
lateral movement of the gas nozzle structure allows streams of
gaseous material ejected from the gas nozzle structure to be
applied to different areas of the semiconductor wafer surface.
Preferably, the semiconductor wafer is rotated by the motor 144 as
the gas nozzle structure is laterally moved across the
semiconductor wafer surface so that the streams of gaseous material
can be applied over the entire wafer surface. The drive mechanism
152 may be further configured to manipulate the mechanical arm 148
so that the gas nozzle structure can be moved in any number of
different possible directions, including the vertical direction to
adjust the distance between the openings 304 of the gas nozzle
structure and the semiconductor wafer surface.
[0048] The gas nozzle structure 104 is connected to the gas
pressure controlling device 110, which controls the pressure of the
streams of gaseous material ejected from the gas nozzle structure.
In the exemplary embodiment, the gas pressure controlling device
includes mass flow controllers 156 and 158. The mass flow
controller 156 controls the pressure of the ozone supplied by the
ozone generator 114, while the mass flow controller 158 controls
the pressure of the gas from the container 138 of the gas supply
126. As described in more detail below, the pressure of the streams
of gaseous material can be adjusted by the gas pressure controlling
device to reduce the thickness of the boundary layer formed on the
surface 102 of the semiconductor wafer W at different locations of
the boundary layer or to create holes through the boundary layer
using the streams of gaseous material. The gas pressure controlling
device 110 is connected to the ozone generator 114, which is
connected to the container 136 of the gas supply 126. The gas
pressure controlling device is also connected to the container 138
of the gas supply. The valves 116, 118 and 120 control the flow of
gas between the containers 136 and 138, the ozone generator 114 and
the gas pressure controlling device 110.
[0049] The controller 108 of the apparatus 100 operates to control
various components of the apparatus. The controller controls the
motor 144, which rotates the semiconductor wafer W via the wafer
support structure 142. The controller also controls the drive
mechanisms 152 and 154, which independently move the gas nozzle
structure 104 and the fluid dispensing structure 146 by
manipulating the mechanical arms 148 and 150. In addition, the
controller controls the gas pressure controlling device 110, the
fluid mixer/selector 112, the valves 116, 118 and 120, and the pump
122.
[0050] The overall operation of the apparatus 100 is described with
reference to the flow diagram of FIG. 4. At step 402, a
semiconductor wafer to be treated, e.g., the semiconductor wafer W,
is placed on the wafer support structure 142 of the single-wafer
spin-type processing unit 106. Next, at step 404, the wafer support
structure is rotated by the motor 144, spinning the semiconductor
wafer. At step 406, a processing fluid is dispensed onto the
semiconductor wafer surface 102 from the fluid dispensing structure
146, as the fluid dispensing structure is laterally moved across
the wafer surface 102 at a predefined distance from the wafer
surface. The dispensed processing fluid forms a boundary layer on
the semiconductor wafer surface. The movement of the fluid
dispensing structure is controlled by the drive mechanism 154,
which manipulates the mechanical arm 150 to move the fluid
dispensing structure. Next, at step 408, streams of gaseous
material, such as ozone, are ejected from the gas nozzle structure
104 onto the semiconductor wafer surface at a controlled pressure,
as the gas nozzle structure is laterally moved across the wafer
surface at a predefined distance from the wafer surface. Due to the
boundary layer formed on the semiconductor wafer surface, the
streams of gaseous material ejected from the gas nozzle structure
are applied to the boundary layer. The movement of the gas nozzle
structure is controlled by the drive mechanism 152, which
manipulates the mechanical arm 148 to move the gas nozzle
structure. The pressure of the streams of gaseous material ejected
from the gas nozzle structure gas is controlled by the gas pressure
controlling device 110.
[0051] In one operational mode, the pressure of the ejected streams
of gaseous material is adjusted by the gas pressure controlling
device 110 so that the streams of gaseous material ejected from the
openings 304 of the gas nozzle structure 104 reduce the thickness
of the boundary layer formed on the semiconductor wafer surface 102
at different locations of the boundary layer, which may be
separated and distinct locations on the boundary layer. As
illustrated in FIG. 5, in this mode, the pressure of the stream of
gaseous material 502 ejected from each opening of the gas nozzle
structure forms a depression 504 on the boundary layer 506. The
characteristics of the depression 504 include the upper diameter A
and the distance B between the lower surface of the depression and
the semiconductor wafer surface 102, which is the thickness of the
boundary layer at the depression. These characteristics are
controlled by the pressure of the ejected stream of gaseous
material, the diameter of the opening 304, the distance between the
opening and the upper surface of the boundary layer 506, and the
initial thickness of the boundary layer, which is determined by the
wafer rotational speed and the amount (or rate) of the dispensed
processing fluid. Where the depressions are formed, the thickness
of the boundary layer is reduced, as shown in FIG. 5. Consequently,
an increased amount of gaseous material reaches the semiconductor
wafer surface through the boundary layer at the depressions by
diffusion due to the reduced thickness of the boundary layer at the
depressions. If the gaseous material is ozone, the increased amount
of ozone to reach the semiconductor wafer surface through diffusion
will promote more oxidation, which results in increased cleaning
and/or oxide growth efficiency.
[0052] In another operational mode, the pressure of the ejected
streams of gaseous material is adjusted by the gas pressure
controlling device 110 so that the ejected streams of gaseous
material from the openings 304 of the gas nozzle structure 104 can
directly contact the semiconductor wafer surface 102. As
illustrated in FIG. 6, in this mode, the pressure of the stream of
gaseous material 502 from each opening of the gas nozzle structure
creates a hole 602 through the boundary layer 506 such that the
gaseous material directly contacts the semiconductor wafer surface.
A characteristic of the hole 602 is the diameter C of the hole at
the semiconductor wafer surface. Similar to the described
depression characteristics A and B, the diameter C of the hole 602
is controlled by the pressure of the ejected stream of gaseous
material, the diameter of the opening 304, the distance between the
opening and the upper surface of the boundary layer 506, and the
initial thickness of the boundary layer. The holes can be created
by increasing the pressure of the streams of gaseous material from
the gas nozzle structure and/or changing other operational
parameters of the apparatus 100, such as the distance between the
openings 304 of the gas nozzle structure 104 and the boundary layer
506. The streams of gaseous material from the different openings of
the gas nozzle structure create an array of exposed regions on the
semiconductor wafer surface that are surrounded by the processing
fluid, i.e., the boundary layer. Since the semiconductor wafer is
typically rotated during processing, the exposed regions of the
wafer surface continuously change as the wafer is rotated. Thus, a
particular region of the semiconductor wafer surface will only be
exposed to a stream of gaseous material gas for a short period of
time, allowing the gaseous material to react with reactable
materials on the wafer surface in the presence of the processing
fluid. It is worth noting that for ozone, a desired oxidizing
reaction with oxidizable materials occurs only in the presence of a
processing fluid, such as deionized water. Thus, if a large region
of the semiconductor wafer surface is exposed to ozone for a long
period, then the desired reaction will not take place between the
ozone and the oxidizable materials on the semiconductor wafer
surface.
[0053] Turning back to FIG. 4, the operation proceeds to step 410,
at which the semiconductor wafer surface 102 is rinsed with
deionized water dispensed from the fluid dispensing structure 146.
During this rinse cycle, the gas nozzle structure 104 may be moved
away from the semiconductor wafer surface. Next, at step 412, the
semiconductor wafer surface is spin-dried by rotating the
semiconductor wafer at a high speed. During this spin-dry cycle,
the gas nozzle structure 104 may eject streams of gaseous material,
such as IPA vaporized gas, to assist in the drying of the
semiconductor wafer surface. At step 414, the semiconductor wafer
is removed from the wafer support structure 142. The operation then
proceeds back to step 402, at which the next semiconductor wafer to
be processed is placed on the wafer support structure. Steps
404-414 are then repeated.
[0054] In other embodiments, the single-wafer spin-type processing
unit 106 may be modified to dispense the processing fluid over the
gas nozzle structure 104 so that the processing fluid and the
streams of gaseous material are applied to a common area of the
semiconductor wafer surface. In FIG. 7, a single-wafer spin-type
processing unit 702 in accordance with a first alternative
embodiment is shown. Same reference numerals of FIG. 1 are used to
identify similar elements in FIG. 7. In this embodiment, the
processing unit 702 includes a fluid dispensing structure 704 that
is positioned over the gas nozzle structure 104. As shown in FIG.
7, the fluid dispensing structure 704 may be connected to the drive
mechanism 154, and thus, can be moved in various directions. In an
alternative configuration, the fluid dispensing structure 704 may
be fixed at a predefined location so that the drive mechanism 154
is not needed. The fluid dispensing structure 704 may include one
or more small openings to spray a processing fluid onto the
semiconductor wafer surface 102 so that the processing fluid is
applied over the entire wafer surface in a substantially even
manner. The fluid dispensing structure 704 may further include an
acoustic transducer 706 to generate a fog of processing fluid using
sonic energy, which allows the processing fluid to be applied more
evenly over the entire semiconductor wafer surface.
[0055] In FIG. 8, a single-wafer spin-type processing unit 802 in
accordance with a second alternative embodiment is shown. Same
reference numerals of FIGS. 1 and 7 are used to identify similar
elements in FIG. 8. The processing unit 802 is similar to the
processing unit 702 of FIG. 7. The main difference between the two
processing units is that the processing unit 802 includes a
bar-type gas nozzle structure 804, which replaces the gas nozzle
structure 104 of the processing unit 702. The fluid dispensing
structure 702, the mechanical arm 150 and the drive mechanism 154
are not shown in FIG. 8. The shape of the bar-type gas nozzle
structure may be any bar-like configuration. As an example, the
bar-type gas nozzle structure may be an elongated structure with a
rectangular or circular cross-section. In other configurations, the
bar-type gas nozzle structure may be curved. The bar-type gas
nozzle structure 804 includes openings 902 on the bottom surface
904 of the structure to eject streams of gaseous material, such as
ozone, as illustrated in FIG. 9. Consequently, the entire
semiconductor wafer surface can be subjected to streams of gaseous
material from the bar-type gas nozzle structure by a single pass of
the gas nozzle structure across the wafer surface.
[0056] In FIG. 10, a single-wafer spin-type processing unit 1002 in
accordance with a third alternative embodiment is shown. Same
reference numerals of FIGS. 1, 7 and 8 are used to identify similar
elements in FIG. 10. The single-wafer spin-type processing unit
1002 of FIG. 10 is similar to the single-wafer spin-type processing
units 702 and 802 of FIGS. 7 and 8. The main difference between the
processing unit 1002 and the processing units 702 and 802 is that
the processing unit 1002 includes a grid-type gas nozzle structure
1004, rather than the gas nozzle structure 104 or the bar-type gas
nozzle structure 804. As illustrated in FIG. 11, which is a bottom
view, the grid-type gas nozzle structure 1004 is configured as a
grid 1102 with openings 1104 to eject streams of gaseous material,
such as ozone. The openings are shown to be located at the
intersections of the grid 1102. However, the openings may be
located at other places on the grid. Due to the grid configuration,
the grid-type gas nozzle structure includes rectangular spaces 1106
that permit the dispensed processing fluid from the fluid
dispensing structure 704, which is positioned above the grid-type
gas nozzle structure, to pass through the grid-type gas nozzle
structure. As stated above, the dispensed processing fluid from the
fluid dispensing structure may be in the form of a spray or fog.
Consequently, the grid-type gas nozzle structure allows both the
processing fluid from the fluid dispensing structure and the
streams of gaseous material from the grid-type gas nozzle structure
to be applied on a common area of the semiconductor wafer surface
102. Although the grid-type gas nozzle structure has been described
and illustrated as being a grid structure, the grid-type nozzle
structure may be any grid-like structure with an array of spaces,
which may be rectangular, circular or any desired shape. As an
example, the grid-type gas nozzle structure may be configured as a
circular disk with an array of circular spaces.
[0057] The operation of an apparatus employing the single-wafer
spin-type processing unit 702, 802 or 1002 is similar to the
operation of the apparatus 100 of FIG. 1. A significant difference
is that, for the apparatus employing the single-wafer spin-type
processing unit 702, 802 or 1002, the processing fluid is dispensed
from the fluid dispensing structure 704 above the gas nozzle
structure 104, 804 or 1104 in the form of a spray or fog, which
allows the processing fluid and the streams of gaseous material
from the gas nozzle structure to be applied to a common area of the
semiconductor wafer surface.
[0058] In FIG. 12, a single-wafer spin-type processing unit 1202 in
accordance with a fourth alternative embodiment is shown. Same
reference numerals of FIGS. 1, 7 and 8 are used to identify similar
elements in FIG. 12. The single-wafer spin-type processing unit
1202 of FIG. 12 is similar to the single-wafer spin-type processing
unit 802 of FIG. 8 in that the single-wafer spin-type processing
unit 1202 also uses a bar-type gas nozzle structure 1204. However,
in contrast to the bar-type gas nozzle structure 804 of the
single-wafer spin-type processing unit 802, the bar-type gas nozzle
structure 1204 includes an elongated gas opening 1302, or a slit,
on the bottom surface 1304 of the structure to eject a single
wall-like stream of gaseous material, such as ozone, as illustrated
in FIG. 13. Although the bar-type gas nozzle structure 1204 is
illustrated in FIG. 13 as including only one elongated gas opening,
the bar-type gas nozzle structure may include additional elongated
gas openings. The bar-type gas nozzle structure 1204 may also
include additional small openings, such as the gas openings 902 of
the bar-type gas nozzle structure 804, shown in FIG. 9. In one
configuration, the single-wafer spin-type processing unit 1202 is
configured such that the bar-type gas nozzle structure 1204 can be
pivoted across the wafer surface 102, as indicated in FIG. 12. In
another configuration, the single-wafer spin-type processing unit
1202 is configured such that the bar-type gas nozzle structure 1204
is stationary with respect to the lateral direction, i.e., the
direction parallel to the wafer surface 102. In either
configuration, the length of the elongated gas opening 1302 is
preferable equal to or greater than the radius of the semiconductor
wafer W so that the gaseous material can be applied to the entire
surface 102 of the wafer when the wafer is rotated. Although not
illustrated, the single-wafer spin-type processing unit 1202 may
include either the fluid dispensing structure 146 or 704. Thus, the
dispensed processing fluid from the fluid dispensing structure of
the single-wafer spin-type processing unit 1202 may be in the form
of a spray or fog.
[0059] In FIG. 14, a single-wafer spin-type processing unit 1402 in
accordance with a fifth alternative embodiment is shown. Same
reference numerals of FIGS. 1, 7 and 8 are used to identify similar
elements in FIG. 14. The single-wafer spin-type processing unit
1402 of FIG. 14 includes a gas nozzle structure 1404, which is
triangular in shape. Specifically, the gas nozzle structure 1404 is
shaped like a sector of a circle. As illustrated in FIG. 15, the
gas nozzle structure 1404 includes gas openings 1502 on the bottom
surface 1504 of the structure to eject streams of gaseous material,
such as ozone. Due to the triangular shape of the gas nozzle
structure 1404, more streams of gaseous material are applied toward
the edge of the wafer surface 102 than toward the center of the
wafer surface. Thus, as the semiconductor wafer W is rotated, the
streams of gaseous material ejected from the gas nozzle structure
1404 are applied to the wafer surface 102 in a substantially equal
manner across the wafer surface. In this embodiment, the
single-wafer spin-type processing unit 1402 is configured such that
the gas nozzle structure 1404 is stationary with respect to the
lateral direction. Although not illustrated, the single-wafer
spin-type processing unit 1402 may include either the fluid
dispensing structure 146 or 704. Thus, the dispensed processing
fluid from the fluid dispensing structure of the single-wafer
spin-type processing unit 1402 may be in the form of a spray or
fog.
[0060] The apparatus 100 employing any of the described
single-wafer spin-type processing unit 106, 702, 802, 1002, 1202 or
1402 can be used to clean a semiconductor wafer surface such that
undesirable materials on the wafer surface, such as photoresist
residue and other contaminants, are removed from the wafer surface
by oxidation and by applied forces on the wafer surface due to the
dispensed processing fluid and/or the ejected streams of gaseous
material. Depending on the cleaning process, which may involve
several cleaning steps using different processing fluids, a native
oxide layer may or may not be formed on the cleaned wafer surface.
The apparatus 100 can also be used to simply grow an oxide layer on
a semiconductor wafer surface, which may be a layer of
silicon-based material (e.g., SiN), during fabrication of a
semiconductor device, such as an integrated circuit. The resulting
oxide layer, which can be a native oxide layer, may be used as a
passivation layer, an interfacial layer or an oxide layer for any
other purpose. As shown in FIG. 16, the apparatus 100 may be used
to grow a passivation oxide layer 1602 over patterned structures
1604 formed on a silicon-based substrate 1606, which may be
metallic interconnect, so that the patterned structures are
protected from the subsequent processing step. As shown in FIG. 17,
the apparatus 100 may also be used to grow an interfacial oxide
layer 1702 over an electrode region 1704 of a transistor formed on
a silicon substrate 1706 such that the interfacial oxide layer is
positioned between the electrode region and an electrode connector
1708. The electrode region 1704 and the electrode connector 1708
may be the emitter region and the emitter connector of a bipolar
transistor, respectively.
[0061] Turning now to FIG. 18, an apparatus 1800 for treating a
surface of a semiconductor wafer, e.g., the semiconductor wafer W,
using a processing fluid in conjunction with a reactive gaseous
agent, such as ozone, to cause a desired reaction of materials on
the wafer surface, such as oxidation, in accordance with a second
embodiment of the invention is shown. The same reference numerals
of FIG. 1 are used to identify similar elements in FIG. 18. Similar
to the apparatus 100 of FIG. 1, the apparatus 1800 can be used to
remove oxidizable materials on the wafer surface and/or to form an
oxide layer on the wafer surface, which may be used as a
passivation or interfacial layer for a semiconductor device.
However, in contrast to the apparatus 100, the apparatus 1800 uses
streams of inert gas in addition to streams of reactive gas to
create depressions on a boundary layer of processing fluid to
reduce the thickness of the boundary layer or to create holes
through the boundary layer to expose portions of the wafer surface.
Preferably, the pressure of the inert gas streams is high enough to
create the depressions and holes alone without the assistance of
the streams of reactive gas. Consequently, the pressure of the
streams of reactive gas can be reduced without significantly
affecting the desired reaction with materials on the wafer surface,
which means that less reactive gas, such as ozone gas, is
needed.
[0062] The streams of inert gas and the streams of reactive gas are
ejected from a gas nozzle structure 1804 of a single-wafer
spin-type processing unit 1806, which is connected to the mass flow
controllers 156 and 158 to receive the reactive gas and the inert
gas. As an example, the reactive gas may be ozone and the inert gas
may be N.sub.2. The reactive gas may also be a mixture of ozone and
N.sub.2 or any other gas. Similar to the gas nozzle structure 104
of the apparatus 100, the gas nozzle structure 1804 includes a
number of gas openings 1902 and 1904 on the bottom surface 1906 of
the structure, as shown in FIG. 19. The gas openings 1902 eject
streams of reactive gas, while the gas openings 1904 eject streams
of inert gas. The gas openings 1902 and 1904 are positioned on the
bottom surface 1906 such that at least one gas opening 1902 is in
close proximity to at least one gas opening 1904. That is, at least
one gas opening 1902 and at least one gas opening 1904 are grouped
together in a small area. Thus, at least one pair of reactive gas
stream and inert gas stream is ejected onto a corresponding small
area of the boundary layer to create depressions on or holes
through the boundary layer, as illustrated in FIG. 20. As shown in
FIG. 20, a stream 2002 of inert gas ejected from a gas opening 1904
of the gas nozzle structure 1804 creates a hole 2004 through a
boundary layer 2006 of processing fluid, which exposes the wafer
surface 102. Alternatively, the stream 2002 of inert gas may simply
create a depression (not shown) on the boundary layer 2006, which
reduces the thickness of the boundary layer at the depression. A
stream 2008 of reactive gas ejected from a gas opening 1902 of the
gas nozzle structure 1804 is applied directly to the exposed wafer
surface through the created hole 2004 or to the created depression
so that the reactive gas can diffuse through the boundary layer
2006 to reach the wafer surface 102. Since the stream 2002 of inert
gas creates the hole or depression, the pressure of the stream 2008
of reactive gas can be reduced. Depending on the pressure, the
stream 2008 of reactive gas may assist in creating the hole 2004
through or the depression on the boundary layer 2006.
[0063] The single-wafer spin-type processing unit 1806 of the
apparatus 1800 can have a configuration similar to the single-wafer
spin-type processing unit 106 of FIG. 1 or the single-wafer
spin-type processing unit 702 of FIG. 7. That is, the single-wafer
spin-type processing unit 1806 can include the fluid dispensing
structure 146, which can be pivoted laterally across the
semiconductor wafer W, or the fluid dispensing structure 704, which
would be positioned over the gas nozzle structure 1804.
Furthermore, the single-wafer spin-type processing unit 1806 may
utilize a bar-type gas nozzle structure, similar to the bar-type
gas nozzle structure 804 of FIGS. 8 and 9, a grid-type gas nozzle
structure, similar to the grid-type gas nozzle structure 1004 of
FIGS. 10 and 11, or a triangular gas nozzle structure, similar to
the triangular gas nozzle structure 1404 of FIGS. 14 and 15.
However, the gas nozzle structure for the single-wafer spin-type
processing unit 1806 includes gas openings for ejecting streams of
reactive gas and gas openings for ejecting streams of inert gas, as
illustrated in FIG. 19 in reference to the gas nozzle structure
1804. Although the gas openings for inert gas and reactive gas may
be grouped as shown in FIG. 19, the gas openings may simply be
distributed randomly, similar to the openings 304 of the gas nozzle
structure 104, shown in FIG. 3, where some of the gas openings are
used to eject streams of reactive gas and some of the gas openings
are used to eject streams of inert gas. The gas openings for
reactive gas and the gas openings for inert gas can be located on
the gas nozzle structure of the single-wafer spin-type processing
unit 1806 in any arrangement.
[0064] In an alternative configuration, the single-wafer spin-type
processing unit 1806 may utilize a gas nozzle structure 2102 having
two elongated gas openings 2104 and 2106 on the bottom surface 2108
of the structure, as illustrated in FIG. 21. The elongated gas
opening 2104 ejects a wall-like stream of reactive gas, while the
elongated gas opening 2106 ejects a wall-like stream of inert gas.
Thus, the wall-like stream of inert gas is used to create an
elongated hole through or an elongated depression on a boundary
layer of processing fluid, while the wall-like stream of reactive
gas is used to apply the reactive gas directly to the exposed wafer
surface or to the elongated depression so that the reactive gas can
diffuse through the boundary layer. The gas nozzle structure 2102
may include additional elongated gas openings to eject wall-like
streams of reactive gas or inert gas. Alternatively, one or more of
the elongated gas openings of the gas nozzle structure 2102 may be
replaced with one or more columns of small gas openings.
[0065] In another alternative configuration, the single-wafer
spin-type processing unit 1806 may utilize a triangular gas nozzle
structure 2202, which is a modified version of the gas nozzle
structure 1404 of FIGS. 14 and 15, as shown in FIGS. 22 and 23.
Similar to the gas nozzle structure 1404, the triangular gas nozzle
structure 2202 includes the gas openings 1502 on the bottom surface
2204 of the structure for ejecting streams of reactive gas.
However, the triangular gas nozzle structure 2202 further includes
either a column 2206 of small gas openings 2208 for ejecting
streams of inert gas, as illustrated in FIG. 22, or an elongated
gas opening 2306 for ejecting a wall-like stream of inert gas, as
illustrated in FIG. 23. The gas nozzle structure 2202 may include
additional columns of small gas openings for ejecting streams of
inert gas and/or additional elongated gas openings for ejecting
wall-like streams of inert gas.
[0066] Although the various gas nozzle structures for the
apparatuses 100 and 1800 have been described as being a single
integrated structure, any of the described gas nozzle structures
may be composed of two or more separate structures. As an example,
the gas nozzle structure 2102 of FIG. 21 may be composed of one
structure having the elongated gas opening 2104 and another
structure having the elongated gas opening 2106. In addition, any
of the described gas nozzle structures may be modified to include
different types of gas openings. As an example, the bar-type gas
nozzle structure 804 of FIGS. 8 and 9 may include one or more
elongated gas openings.
[0067] A method for treating a surface of a semiconductor wafer
with a reactive gas, such as ozone, in accordance with an
embodiment of the invention is described with reference to the
process flow diagram of FIG. 24. At step 2402, a semiconductor
wafer to be treated is rotated. Next, at step 2404, a layer of
processing fluid is formed on a surface of the semiconductor wafer.
The processing fluid layer may be formed by dispensing the
processing fluid in the form of a spray or fog. At step 2406, at
least one stream of gaseous material is ejected through the layer
of processing fluid onto the wafer surface to expose a portion of
the wafer surface. In addition, the reactive gas is introduced to
the exposed portion of the wafer surface to allow the reactive gas
to react with the wafer surface. The reactive gas may be introduced
as part of the stream of gaseous material. Alternatively, the
reactive gas may be introduced as one or more separate streams of
reactive gas. The reaction of the reactive gas with the wafer
surface may form a layer of reacted material, e.g., an oxide layer,
on the wafer surface, which may be used as a passivation layer, an
interfacial layer or an oxide layer for any other purpose.
[0068] A method for treating a surface of a semiconductor wafer
with a reactive gas, such as ozone, in accordance with another
embodiment of the invention is described with reference to the
process flow diagram of FIG. 25. At step 2502, a semiconductor
wafer to be treated is rotated. Next, at step 2504, a layer of
processing fluid is formed on a surface of the semiconductor wafer.
Again, the processing fluid layer may be formed by dispensing the
processing fluid in the form of a spray or fog. At step 2506,
multiple streams of gaseous material are ejected onto the layer of
processing fluid to form multiple depressions on the layer of
processing fluid. The depressions may be formed at separated and
distinct locations on the layer of processing fluid. In addition,
the reactive gas is introduced to the depressions to allow the
reactive gas to reach and react with the wafer surface. Again, the
reactive gas may be introduced as part of the streams of gaseous
material. Alternatively, the reactive gas may be introduced as one
or more separate streams of reactive gas. Again, the reaction of
the reactive gas with the wafer surface may form a layer of reacted
material, e.g., an oxide layer, on the wafer surface.
[0069] A method for treating a surface of a semiconductor wafer
with a reactive gas, such as ozone, in accordance with still
another embodiment of the invention is described with reference to
the process flow diagram of FIG. 26. At step 2602, a semiconductor
wafer to be treated is rotated. Next, at step 2604, a layer of
processing fluid is formed on a surface of the semiconductor wafer.
The processing fluid layer may be formed by dispensing the
processing fluid in the form of a spray or fog. At step 2606, at
least one wall-like stream of gaseous material is ejected onto the
layer of processing fluid on the wafer surface, which may create a
depression on the layer of processing fluid or a hole through the
layer of processing fluid. In addition, the reactive gas is
introduced to allow the reactive gas to reach and react with the
wafer surface. The reactive gas may be introduced as part of the
wall-like stream of gaseous material. Alternatively, the reactive
gas may be introduced as one or more separate streams of reactive
gas, which may include a wall-like stream of reactive gas. Again,
the reaction of the reactive gas with the wafer surface may form a
layer of reacted material, e.g., an oxide layer, on the wafer
surface.
[0070] Although specific embodiments of the invention have been
described and illustrated, the invention is not to be limited to
the specific forms or arrangements of parts so described and
illustrated. As an example, the invention may be used to clean
and/or grow an oxide layer on an object other than a semiconductor
wafer. In addition, the desired reaction may be a reaction other
than oxidation using a gas other than ozone. The scope of the
invention is to be defined by the claims appended hereto and their
equivalents.
* * * * *