Reactors, systems with reaction chambers, and methods for depositing materials onto micro-device workpieces
Reactors, systems with reaction chambers, and methods for depositing materials onto micro-device workpieces are disclosed herein. In one embodiment, a method for depositing material onto a micro-device workpiece includes flowing a first gas along a first vector across a first portion and toward a center of the micro-device workpiece and flowing a second gas along a second vector across a second portion and toward the center of the micro-device workpiece. The second vector is transverse to the first vector. The method can further include exhausting the first gas from a region proximate to the center of the micro-device workpiece and exhausting the second gas from the region proximate to the center of the micro-device workpiece. Flowing the first gas can include depositing the first gas uniformly from a perimeter region to a center region of the micro-device workpiece.
The present invention is related to reactors, systems with reaction chambers, and methods for depositing materials used in the manufacturing of micro-devices.
BACKGROUNDThin film deposition techniques are widely used in the manufacturing of micro-devices to form a coating on a workpiece that closely conforms to the surface topography. The size of the individual components in the devices is constantly decreasing, and the number of layers in the devices is increasing. As a result, the density of components and the aspect ratios of depressions (e.g., the ratio of the depth to the size of the opening) are increasing. The size of workpieces is also increasing to provide more real estate for forming more dies (i.e., chips) on a single workpiece. Many fabricators, for example, are transitioning from 200 mm to 300 mm workpieces, and even larger workpieces will likely be used in the future. Thin film deposition techniques accordingly strive to produce highly uniform conformal layers that cover the sidewalls, bottoms, and corners in deep depressions that have very small openings.
One widely used thin film deposition technique is Chemical Vapor Deposition (CVD). In a CVD system, one or more precursors that are capable of reacting to form a solid thin film are mixed in a gas or vapor state, and then the precursor mixture is presented to the surface of the workpiece. The surface of the workpiece catalyzes the reaction between the precursors to form a solid thin film at the workpiece surface. A common way to catalyze the reaction at the surface of the workpiece is to heat the workpiece to a temperature that causes the reaction.
Although CVD techniques are useful in many applications, they also have several drawbacks. For example, if the precursors are not highly reactive, then a high workpiece temperature is needed to achieve a reasonable deposition rate. Such high temperatures are not typically desirable because heating the workpiece can be detrimental to the structures and other materials already formed on the workpiece. Implanted or doped materials, for example, can migrate within the silicon substrate at higher temperatures. On the other hand, if more reactive precursors are used so that the workpiece temperature can be lower, then reactions may occur prematurely in the gas phase before reaching the substrate. This is undesirable because the film quality and uniformity may suffer, and also because it limits the types of precursors that can be used.
Atomic Layer Deposition (ALD) is another thin film deposition technique.
One drawback of ALD processing is that it has a relatively low throughput compared to CVD techniques. For example, ALD processing typically takes about eight to eleven seconds to perform each Ax-purge-By-purge cycle. This results in a total process time of approximately eight to eleven minutes to form a single thin layer of only 60 Å. In contrast to ALD processing, CVD techniques only require about one minute to form a 60 Å thick layer. The low throughput of existing ALD techniques limits the utility of the technology in its current state because ALD may be a bottleneck in the overall manufacturing process.
Another drawback of both CVD and ALD processing is that it is difficult to deposit the precursors uniformly across the workpiece. For example, typical conventional reactors flow the precursors either (a) laterally across the workpiece (not shown) or (b) vertically downward onto a center region of the workpiece and then radially outward across a perimeter region of the workpiece (
The present invention relates to reactors, systems with reaction chambers, and methods for depositing materials used in the manufacturing of micro-devices. One aspect of the invention is directed to a method for depositing material onto a micro-device workpiece in a reaction chamber. In one embodiment, the method includes flowing a first gas along a first vector across a first portion and toward a center of the micro-device workpiece and flowing a second gas along a second vector across a second portion and toward the center of the micro-device workpiece. The second vector is transverse to the first vector. In one aspect of this embodiment, the method further includes exhausting the first gas from a region proximate to the center of the micro-device workpiece and exhausting the second gas from the region proximate to the center of the micro-device workpiece. In another aspect of this embodiment, flowing the first gas includes depositing a first thickness of the first gas molecules onto the micro-device workpiece proximate to a perimeter and depositing a second thickness of the first gas molecules onto the micro-device workpiece proximate to the center. The first thickness is generally equal to the second thickness.
In another embodiment, the method includes flowing a gas across a surface of the micro-device workpiece from a perimeter region toward a center region and exhausting the gas from the center region of the micro-device workpiece. In one aspect of this embodiment, flowing the gas includes uniformly depositing the gas across a first area from a perimeter to a center of the micro-device workpiece. In another aspect of this embodiment, flowing the gas includes decreasing the density of the gas as the gas moves toward the center of the micro-device workpiece. In another aspect of this embodiment, flowing the gas includes flowing a first precursor. The method can further include flowing a second precursor across and toward the center of the micro-device workpiece at least partially simultaneously with the first precursor flow. Alternatively, the method can further include flowing a purge gas toward the center of the micro-device workpiece after terminating the first precursor flow and flowing a second precursor after terminating the purge gas flow.
Another aspect of the invention is directed to a reactor for depositing material onto a micro-device workpiece in a reaction chamber. In one embodiment, the reactor includes a reaction chamber and a gas distributor carried by the reaction chamber. The gas distributor includes a first aperture arranged to flow a first gas across a first portion and toward a center of the micro-device workpiece and a second aperture arranged to flow a second gas across a second portion and toward the center of the micro-device workpiece. The first portion of the micro-device workpiece is different than the second portion. In one aspect of this embodiment, the reactor further includes an exhaust conduit coupled to the reaction chamber. The exhaust conduit has a port proximate to a center of the micro-device workpiece to remove the first and second gases from the reaction chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
The following disclosure describes several embodiments of reactors having gas distributors, systems including reaction chambers, and methods for depositing materials onto micro-device workpieces. Many specific details of the invention are described below with reference to reactors for depositing materials onto micro-device workpieces. The term “micro-device workpiece” is used throughout to include substrates upon which and/or in which microelectronic devices, micromechanical devices, data storage elements, read/write components, and other features are fabricated. For example, micro-device workpieces can be semiconductor wafers such as silicon or gallium arsenide wafers, glass substrates, insulative substrates, and many other types of materials. Furthermore, the term “gas” is used throughout to include any form of matter that has no fixed shape and will conform in volume to the space available, which specifically includes vapors (i.e., a gas having a temperature less than the critical temperature so that it may be liquefied or solidified by compression at a constant temperature).
Moreover, the term “transverse” is used throughout to mean oblique, perpendicular, and/or not parallel. Several embodiments in accordance with the invention are set forth in
A. Deposition Systems
The gas supply 130 includes a plurality of gas sources 132 (identified individually as 132a-c), a valve assembly 133 having a plurality of valves, and a plurality of gas supply lines 136 and 137. The gas sources 132 can include a first gas source 132a for providing a first gas, a second gas source 132b for providing a second gas, and a third gas source 132c for providing a third gas. The first and second gases can be first and second precursors, respectively. The third gas can be a purge gas. The first and second precursors are the gas or vapor phase constituents that react to form the thin, solid layer on the workpiece W. The purge gas can be a suitable type of gas that is compatible with the reaction chamber 120 and the workpiece W. The gas supply 130 can include more gas sources 132 for applications that require additional precursors or purge gases in other embodiments. In additional embodiments, the gas sources 132 can include one or more etchants for deposition onto a micro-device workpiece during etching. The valve assembly 133 is operated by a controller 142 that generates signals for controlling the flow of gases through the reaction chamber 120 for ALD and CVD applications. For example, the controller 142 can be programmed to operate the valve assembly 133 to pulse the gases individually through the gas distributor 160 in ALD applications or mix selected precursors in the gas distributor 160 in CVD applications.
In the illustrated embodiment, the reactor 110 also includes a workpiece support 150 to hold the workpiece W in the reaction chamber 120. In one aspect of this embodiment, the workpiece support 150 can be heated to bring the workpiece W to a desired temperature for catalyzing the reaction between the first gas and the second gas at the surface of the workpiece W. For example, the workpiece support 150 can be a plate with a heating element. The workpiece support 150, however, may not be heated in other applications.
B. Gas Distributors
The gas distributor 160 flows the gas(es) across the workpiece W in the reaction chamber 120 to deposit material onto the workpiece W. In the illustrated embodiment, the gas distributor 160 is carried by the reaction chamber 120 and has an annular configuration circumscribing the workpiece W. The gas distributor 160 is coupled to the gas supply lines 137 to receive the gases through an inlet 122. The gas distributor 160 includes a wall 162, an antechamber or conduit 168 defined by the wall 162, and a plurality of apertures 166 in the wall 162. The apertures 166 are arranged to flow the gases across the workpiece W from a perimeter region to an interior region. More specifically, the gases flow radially inward toward the center of the workpiece W and generally parallel to a surface of the workpiece W. At the center of the workpiece W, the vacuum 140 removes the gases through an exhaust conduit 125. For example, a gas flow “F1” enters the reaction chamber 120 through the apertures 166 in the gas distributor 160, flows over the workpiece W, and then is exhausted from the reaction chamber 120 through an outlet 124.
One feature of the embodiment illustrated in
In additional embodiments, the first and second apertures can be configured to flow the gas at an angle relative to the center C of the workpiece W to create a vortex over the workpiece W. In other embodiments, apertures can be configured to flow the gas in diametrically opposed directions. In additional embodiments, the apertures can be configured to flow the gas over a specific segment of the workpiece W. In other embodiments, such as in dry etch applications, the reaction chamber can also include an electrode and the workpiece W can be electrically biased.
One feature of this embodiment is that the gas flows radially inward from a perimeter P of the workpiece W toward the center C of the workpiece W. The gas is depleted as the gas flows across the workpiece W because portions of the gas are deposited on the workpiece W. Moreover, the surface area of the workpiece W serviced by each aperture decreases as the gas from the aperture flows toward the center C of the workpiece W. Accordingly, one advantage of this embodiment is that the gas is deposited generally uniformly across the workpiece W because, as the gas is depleted, there is less surface area on the workpiece W onto which the gas is deposited.
Referring to
D. Other Reactors
In one aspect of this embodiment, the reactor 310 also includes a workpiece support 350 having a heater. The gas distributor 360 is arranged such that the apertures 366 flow the gases proximate to the heated workpiece support 350 to heat the gases before the gases flow across the workpiece W. In other embodiments, the workpiece support 350 may not include a heater or heat the gases before the gases flow across the workpiece W.
From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.
Claims
1-44. (Cancelled)
45. The reactor of claim 4644 wherein:
- the first inlet projects the first gas flow radially inward; and
- the second inlet projects the second gas flow radially inward.
46. A reactor for depositing material onto a surface of a micro-device workpiece in a reaction chamber, the reactor comprising:
- a reaction chamber;
- a gas distributor carried by the reaction chamber, the gas distributor comprising a first gas conduit having a first inlet and a second gas conduit having a second inlet, wherein the first inlet projects a first gas flow along a first vector and the second inlet projects a second gas flow along a second vector transverse to the first vector, wherein the first and second vectors are generally parallel to the surface of the micro-device workpiece; and
- an exhaust conduit coupled to the reaction chamber, the exhaust conduit having a port proximate to a center region of the micro-device workpiece to remove the first and second gases from the reaction chamber.
47. The reactor of claim 4644 wherein the first gas conduit has a plurality of first inlets arranged in a generally annular configuration, and wherein the second gas conduit has a plurality of second inlets arranged in a generally annular configuration.
48. (Cancelled)
49. A reactor for depositing material onto a micro-device workpiece in a reaction chamber, the reactor comprising:
- a reaction chamber:
- a gas distributor carried by the reaction chamber, the gas distributor comprising a first aperture arranged to flow a first gas across a first portion and toward a center of the micro-device workpiece and a second aperture arranged to flow a second gas across a second portion and toward the center of the micro-device workpiece, wherein the first portion of the micro-device workpiece is different than the second portion; and
- an exhaust conduit coupled to the reaction chamber, the exhaust conduit having a port proximate to the center of the micro-device workpiece to remove the first and second gases from the reaction chamber.
50. The reactor of claim 49 wherein the gas distributor further comprises a plurality of first apertures arranged in a generally annular configuration to flow the first gas toward the center of the micro-device workpiece and a plurality of second apertures arranged in a generally annular configuration to flow the second gas toward the center of the micro-device workpiece.
51. A reactor for depositing material onto a micro-device workpiece in a reaction chamber, the reactor comprising:
- a reaction chamber;
- a gas distributor carried by the reaction chamber, the gas distributor comprising a first aperture arranged to flow a first gas across a first portion and toward a center of the micro-device workpiece and a second aperture arranged to flow a second gas across a second portion and toward the center of the micro-device workpiece, wherein the first portion of the micro-device workpiece is different than the second portion;
- a workpiece support in the reaction chamber; and
- a heater carried by the workpiece support;
- wherein the first aperture is configured to flow the first gas proximate to the heater and the second aperture is configured to flow the second gas proximate to the heater.
52. The reactor of claim 49 wherein the gas distributor further comprises a first injector having the first aperture and a second injector having the second aperture.
53. The reactor of claim 49 wherein the first aperture is configured to flow the first gas in a first direction and the second aperture is configured to flow the second gas in a second direction diametrically opposed to the first direction.
54. The reactor of claim 49 wherein the first aperture is coupled to a first gas conduit and the second aperture is coupled to a second gas conduit different than the first gas conduit.
55. (Cancelled)
56. A reactor for depositing material onto a micro-device workpiece in a reaction chamber, the reactor comprising:
- a reaction chamber;
- a gas distributor carried by the reaction chamber, the gas distributor comprising a plurality of apertures arranged generally annularly about the micro-device workpiece and configured to flow a gas radially inward across corresponding portions of the workpiece from a perimeter region to a central region; and
- an exhaust conduit coupled to the reaction chamber, the exhaust conduit having a port proximate to the central region of the micro-device workpiece to remove the gas from the reaction chamber.
57. A reactor for depositing material onto a micro-device workpiece in a reaction chamber, the reactor comprising:
- a reaction chamber;
- a gas distributor carried by the reaction chamber, the gas distributor comprising a plurality of apertures arranged generally annularly about the micro-device workpiece and configured to flow a gas radially inward across corresponding portions of the workpiece from a perimeter region to a central region;
- a workpiece support in the reaction chamber; and
- a heater carried by the workpiece support;
- wherein the plurality of apertures are configured to flow the gas proximate to the heater.
58. The reactor of claim 56 wherein the gas distributor has an annular configuration.
59. The reactor of claim 56 wherein the apertures include first and second apertures, and wherein the first aperture is configured to flow the gas in a first direction and the second aperture is configured to flow the gas in a second direction diametrically opposed to the first direction.
60. The reactor of claim 56 wherein the apertures include first and second apertures, and wherein the first aperture is coupled to a first gas conduit and the second aperture is coupled to a second gas conduit different than the first gas conduit.
61. The reactor of claim 56 wherein the gas distributor further comprises an antechamber in fluid communication with the apertures.
62. A system for depositing material onto a micro-device workpiece in a reaction chamber, the system comprising:
- a gas supply assembly having a first gas source and a second gas source;
- a reaction chamber;
- a workpiece support in the reaction chamber, the workpiece support having a center region and a perimeter region surrounding the center region;
- a gas distributor carried by the reaction chamber and coupled to the gas supply assembly, the gas distributor comprising a first aperture proximate to the perimeter region of the workpiece support and a second aperture proximate to the perimeter region of the workpiece support, wherein a first gas flows through the first aperture and a second gas flows through the second aperture; and
- an exhaust conduit coupled to the reaction chamber, the exhaust conduit having a port proximate to the center region of the workpiece support to remove the first and second gases from the reaction chamber.
63. The system of claim 62 wherein the gas distributor further comprises a plurality of first apertures proximate to the perimeter region and arranged in a generally annular configuration to flow the first gas toward the center of the micro-device workpiece and a plurality of second apertures proximate to the perimeter region and arranged in a generally annular configuration to flow the second gas toward the center of the micro-device workpiece.
64. The system of claim 62 wherein the gas distributor further comprises a first injector having the first aperture and a second injector having the second aperture.
65. A system for depositing material onto a surface of a micro-device workpiece in a reaction chamber, the system comprising:
- a gas supply assembly having a first gas source and a second gas source;
- a reaction chamber;
- a workpiece support in the reaction chamber;
- a gas distributor carried by the reaction chamber and coupled to the gas supply assembly, the gas distributor comprising a first gas conduit having a first inlet and a second gas conduit having a second inlet, wherein the first inlet projects a first gas flow along a first vector and the second inlet projects a second gas flow along a second vector transverse to the first vector, wherein the first and second vectors are generally parallel to the surface of the micro-device workpiece; and
- an exhaust conduit coupled to the reaction chamber, the exhaust conduit having a port proximate to a center of the micro-device workpiece to remove the first and second gases from the reaction chamber.
66. The system of claim 65 wherein:
- the first inlet projects the first gas flow radially inward; and
- the second inlet projects the second gas flow radially inward.
67. The system of claim 65 wherein the first gas conduit has a plurality of first inlets arranged in a generally annular configuration, and wherein the second gas conduit has a plurality of second inlets arranged in a generally annular configuration.
68. A system for depositing material onto a micro-device workpiece in a reaction chamber, the system comprising:
- a gas supply assembly having a first gas source and a second gas source;
- a reaction chamber;
- a workpiece support in the reaction chamber;
- a gas distributor carried by the reaction chamber and coupled to the gas supply assembly, the gas distributor comprising a first aperture arranged to flow a first gas across a first portion and toward a center of the micro-device workpiece and a second aperture arranged to flow a second gas across a second portion and toward the center of the micro-device workpiece, wherein the first portion of the micro-device workpiece is different than the second portion; and
- an exhaust conduit coupled to the reaction chamber, the exhaust conduit having a port proximate to the center of the micro-device workpiece to remove the first and second gases from the reaction chamber.
69. The system of claim 68 wherein the gas distributor further comprises a plurality of first apertures arranged in a generally annular configuration to flow the first gas toward the center of the micro-device workpiece and a plurality of second apertures arranged in a generally annular configuration to flow the second gas toward the center of the micro-device workpiece.
70. The system of claim 68, further comprising a heater carried by the workpiece support, wherein the first aperture is configured to flow the first gas proximate to the heater and the second aperture is configured to flow the second gas proximate to the heater.
71. A system for depositing material onto a micro-device workpiece in a reaction chamber, the system comprising:
- a gas supply assembly having a first gas source and a second gas source;
- a reaction chamber;
- a workpiece support in the reaction chamber;
- a gas distributor carried by the reaction chamber and coupled to the gas supply assembly, the gas distributor comprising a plurality of apertures arranged generally annularly about the micro-device workpiece and configured to flow a gas radially inward across corresponding portions of the workpiece from a perimeter region to a central region; and
- an exhaust conduit coupled to the reaction chamber, the exhaust conduit having a port proximate to the central region of the micro-device workpiece to remove the gas from the reaction chamber.
72. The system of claim 71, further comprising a heater carried by the workpiece support, wherein the plurality of apertures are configured to flow the gas proximate to the heater.
73. The system of claim 71 wherein the gas distributor further comprises a plurality of injectors having the apertures.
Type: Application
Filed: Oct 5, 2004
Publication Date: Mar 3, 2005
Inventor: Garo Derderian (Boise, ID)
Application Number: 10/959,448