US20160319422A1

US20160319422A1 - Thin film encapsulation processing system and process kit permitting low-pressure tool replacement

Info

Publication number: US20160319422A1
Application number: US15/108,119
Authority: US
Inventors: Shinichi Kurita; Jozef Kudela; John M. White; Dieter Haas
Original assignee: Applied Materials Inc
Current assignee: Applied Materials Inc
Priority date: 2014-01-21
Filing date: 2015-01-20
Publication date: 2016-11-03
Also published as: TW201542861A; CN106415876B; TWI670389B; TW201539617A; KR20160111963A; TWI641066B; CN105934837A; KR102458230B1; KR102330725B1; KR102302720B1; KR20210144933A; US10184179B2; WO2015112470A1; KR20160111962A; JP2017505987A; CN106415876A; US20160362788A1; JP2017504725A; WO2015112467A1; CN105934837B

Abstract

The present disclosure relates to methods and apparatus for a thin film encapsulation (TFE). A process kit for TFE is provided. The process kit is an assembly including a window, a mask parallel to the window, and a frame. The process kit further includes an inlet channel for flowing process gases into the volume between the window and the mask, an outlet channel for pumping effluent gases away from the volume between the window and the mask, and seals for inhibiting the flow of process gases and effluent gases to undesired locations. A method of performing TFE is provided, including placing a substrate under the mask of the above described process kit, flowing process gases into the process kit, and activating some of the process gases into reactive species by means of an energy source within a processing chamber.

Description

BACKGROUND

1. Field
Embodiments of the present disclosure generally relate to an apparatus for processing large area substrates. More particularly, embodiments of the present disclosure relate to an atomic layer deposition (ALD) system for device fabrication and in situ cleaning methods for a showerhead of the same.
2. Description of the Related Art
Organic light emitting diodes (OLED) are used in the manufacture of television screens, computer monitors, mobile phones, other hand-held devices, etc. for displaying information. A typical OLED may include layers of organic material situated between two electrodes that are all deposited on a substrate in a manner to form a matrix display panel having pixels that may be individually energized. The OLED is generally placed between two glass panels, and the edges of the glass panels are sealed to encapsulate the OLED therein.
The OLED industry, as well as other industries that utilize substrate processing techniques, must encapsulate moisture-sensitive devices to protect them from ambient moisture exposure. A thin conformal layer of material has been proposed as a means of reducing Water Vapor Transmission Rate (WVTR) through encapsulation layer(s). Currently, there are a number of ways this is being done commercially. Using an ALD process to cover a moisture-sensitive device is being considered to determine if the conformal nature of these coatings can provide a more effective moisture barrier than other coatings.
ALD is based upon atomic layer epitaxy (ALE) and employs chemisorption techniques to deliver precursor molecules on a substrate surface in sequential cycles. The cycle exposes the substrate surface to a first precursor and then to a second precursor. Optionally, a purge gas may be introduced between introductions of the precursors. The first and second precursors react to form a product compound as a film on the substrate surface. The cycle is repeated to form the layer to a desired thickness.
One method of performing ALD is by Time-Separated (TS) pulses of precursor gases. This method has several advantages over other methods, however one drawback of TS-ALD is that every surface (e.g., the interior of the chamber) exposed to the precursors will be coated with deposition. If these deposits are not removed periodically, they will tend to flake and peel off eventually, leading to particulates ending up on the substrate and hence degraded moisture barrier performance of the deposited layer. If there is no effective way to clean the undesired deposits from the chamber surfaces in situ, then those chamber surfaces must be removed for cleaning “off-line”. If the chamber has to be opened to accomplish removing and replacing chamber surfaces for cleaning, then vacuum has to be broken in the chamber (e.g., the chamber is brought to atmospheric pressure) and this breaking of vacuum will lead to excessive chamber down-time.
There is a need, therefore, for a processing chamber allowing for removal and cleaning of the main key elements of the chamber which will accumulate extraneous deposits with minimal down-time.

SUMMARY

A process kit for use in an ALD chamber is provided. The process kit generally includes a window, a mask disposed parallel to the window, and a frame connected with the window and the mask. The frame has at least one inlet channel connecting a first outer surface of the frame with a first inner surface of the frame, wherein the first inner surface is between the window and the mask. The frame also has at least one outlet channel connecting a second outer surface of the frame with a second inner surface of the frame, wherein the second inner surface of the frame is between the window and the mask.
In another embodiment, a processing system for performing ALD is provided. The processing system generally includes an ALD processing chamber, wherein pressure within the ALD processing chamber is maintained at 1 torr or less and the ALD processing chamber has a first slit valve opening configured to permit passage of a process kit therethrough. The processing system further includes a first slit valve operable to open and close the first slit valve opening of the ALD processing chamber, wherein the first slit valve is operable to make an air-tight seal when closed, an inlet manifold operable to press against seals of a process kit and enable a flow of gases to an inlet channel of the process kit, an outlet manifold operable to press against seals of the process kit and enable a flow of gases from an outlet channel of the process kit, and one or more differential pump and purge assemblies operable to press against seals of the process kit and pump gases away from the process kit.
In another embodiment, a method for performing ALD is provided. The method generally includes positioning a substrate and a process kit within an ALD processing chamber, wherein the process kit includes a window, a mask disposed parallel to the window, and a frame connected with the window and the mask. The frame has at least one inlet channel connecting a first outer surface of the frame with a first inner surface of the frame, wherein the first inner surface is between the window and the mask. The frame also has at least one outlet channel connecting a second outer surface of the frame with a second inner surface of the frame, wherein the second inner surface of the frame is between the window and the mask. Positioning the process kit within the ALD processing chamber generally includes pressing seals around an opening of an inlet channel of the process kit against an inlet manifold of the ALD processing chamber, pressing seals around an opening of an outlet channel of the process kit against an outlet manifold of the ALD processing chamber, and pressing other seals of the process kit against differential pump and purge assemblies of the ALD processing chamber. The method further includes flowing process gases via the inlet manifold into the process kit and pumping effluent gases out of the process kit via the outlet manifold.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.

FIG. 1 illustrates an exemplary processing system, according to certain aspects of the present disclosure.

FIG. 2 illustrates a side view of an exemplary chamber for ALD, according to certain aspects of the present disclosure.

FIG. 3 illustrates a front view of an exemplary chamber for ALD, according to certain aspects of the present disclosure.

FIGS. 4A and 4B illustrate a process kit within a processing chamber, according to aspects of the present disclosure.

FIG. 5 illustrates a process kit, according to aspects of the present disclosure.

FIGS. 6A, 6B, and 6C show positions of a process kit and substrate in a processing chamber, according to aspects of the present disclosure.

FIG. 7 illustrates a front view of an exemplary chamber for ALD, according to certain aspects of the present disclosure.

FIG. 8 illustrates a process kit, according to aspects of the present disclosure.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation.

DETAILED DESCRIPTION

Embodiments of the present disclosure include a processing system that is operable to deposit a plurality of layers on a substrate, the plurality of layers capable of acting as an encapsulation layer on an OLED formed on the substrate. The system includes a plurality of processing chambers, with each processing chamber operable to deposit one or more of the plurality of layers. The processing system further includes at least one transfer chamber and at least one load lock chamber. The at least one transfer chamber enables transfer of substrates between the plurality of processing chambers without breaking vacuum in the processing system. The at least one load lock chamber enables loading and removal of substrates from the processing system without breaking vacuum in the processing system. The processing system further includes a mask chamber that enables loading and removal of masks used in the processing chambers without breaking vacuum in the processing system.
Embodiments of the disclosure include chemical vapor deposition (CVD) processing chambers that are operable to align a mask with respect to a substrate, position the mask on the substrate, and perform CVD to deposit an encapsulation layer on an OLED formed on the substrate. The CVD process performed in the CVD processing chambers may be plasma-enhanced CVD (PECVD), but the embodiments described herein may be used with other types of processing chambers and are not limited to use with PECVD processing chambers. The encapsulation layers deposited by the CVD processing chambers may comprise silicon nitride SiN, but the embodiments described herein may be used with other types of processing chambers and are not limited to use with SiN CVD processing chambers.
Embodiments of the disclosure include an atomic layer deposition (ALD) processing chamber that is operable to align a mask with respect to a substrate, position the mask on the substrate, and perform ALD to deposit an encapsulation layer on an OLED formed on the substrate. The ALD process performed in the ALD processing chamber may be time-separated ALD (TS-ALD), but the embodiments described herein may be used with other types of processing chambers and are not limited to use with TS-ALD processing chambers. The encapsulation layers deposited by the ALD processing chambers may comprise aluminum oxide Al₂O₃, but the embodiments described herein may be used with other types of processing chambers and are not limited to use with SiN CVD processing chambers.
The embodiments described herein may be used with other types of deposition processes and are not limited to use for encapsulating OLEDs formed on substrates. The embodiments described herein may be used with various types, shapes, and sizes of masks and substrates.
The substrate is not limited to any particular size or shape. In one aspect, the term “substrate” refers to any polygonal, squared, rectangular, curved or otherwise non-circular workpiece, such as a glass substrate used in the fabrication of flat panel displays, for example.
In the description that follows, the terms “gas” and “gases” are used interchangeably, unless otherwise noted, and refer to one or more precursors, reactants, catalysts, carrier gases, purge gases, cleaning gases, effluent, combinations thereof, as well as any other fluid.
FIG. 1 is a cross sectional top view showing an illustrative processing system 100, according to one embodiment of the present disclosure. The processing system 100 includes a load-lock chamber 104, a transfer chamber 106, a handling (e.g., tool and material handling) robot 108 within the transfer chamber 106, a first CVD processing chamber 110, a second CVD processing chamber 112, a control station 114, an ALD processing chamber 116, and a mask chamber 118. The first CVD processing chamber 110, second CVD processing chamber 112, ALD processing chamber 116, and each chamber's associated hardware are preferably formed from one or more process-compatible materials, such as aluminum, anodized aluminum, nickel plated aluminum, stainless steel, quartz, and combinations and alloys thereof, for example. The first CVD processing chamber 110, second CVD processing chamber 112, and ALD processing chamber 116 may be round, rectangular, or another shape, as required by the shape of the substrate to be coated and other processing requirements.
The transfer chamber 106 includes slit valve openings 121, 123, 125, 127, 129 in sidewalls adjacent to the load-lock chamber 104, first CVD processing chamber 110, second CVD processing chamber 112, ALD processing chamber 116, and mask chamber 118. The handling robot 108 is positioned and configured to be capable of inserting one or more tools (e.g., substrate handling blades) through each of the slit valve openings 121, 123, 125, 127, 129 and into the adjacent chamber. That is, the handling robot can insert tools into the load-lock chamber 104, the first CVD processing chamber 110, the second CVD processing chamber 112, the ALD processing chamber 116, and the mask chamber 118 via slit valve openings 121, 123, 125, 127, 129 in the walls of the transfer chamber 106 adjacent to each of the other chambers. The slit valve openings 121, 123, 125, 127, 129 are selectively opened and closed with slit valves 120, 122, 124, 126, 128 to allow access to the interiors of the adjacent chambers when a substrate, tool, or other item is to be inserted or removed from one of the adjacent chambers.
The transfer chamber 106, load lock chamber 104, first CVD processing chamber 110, second CVD processing chamber 112, ALD processing chamber 116, and mask chamber 118 include one or more apertures (not shown) that are in fluid communication with a vacuum system (e.g., a vacuum pump). The apertures provide an egress for the gases within the various chambers. In some embodiments, the chambers are each connected to a separate and independent vacuum system. In still other embodiments, some of the chambers share a vacuum system, while the other chambers have separate and independent vacuum systems. The vacuum systems can include vacuum pumps (not shown) and throttle valves (not shown) to regulate flows of gases through the various chambers.
Masks, mask frames, and other items placed within the first CVD chamber 110, second CVD chamber 112, and ALD processing chamber 116, other than substrates, may be referred to as a “process kit.” Process kit items may be removed from the processing chambers for cleaning or replacement. The transfer chamber 106, mask chamber 118, first CVD processing chamber 110, second CVD processing chamber 112, and ALD processing chamber 116 are sized and shaped to allow the transfer of masks, mask frames, and other process kit items between them. That is, the transfer chamber 106, mask chamber 118, first CVD processing chamber 110, second CVD processing chamber 112, and ALD processing chamber 116 are sized and shaped such that any process kit item can be completely contained within any one of them with all of the slit valve openings 121, 123, 125, 127, 129 closed by each slit valve opening's 121, 123, 125, 127, 129 corresponding slit valve 120, 122, 124, 126, 128. Thus, process kit items may be removed and replaced without breaking vacuum of the processing system, as the mask chamber 118 acts as an airlock, allowing process kit items to be removed from the processing system without breaking vacuum in any of the chambers other than the mask chamber. Furthermore, the slit valve opening 129 between the transfer chamber 106 and the mask chamber 118, the slit valve openings 123, 125 between the transfer chamber 106 and the CVD processing chambers 110, 112, and the slit valve opening 127 between the transfer chamber 106 and the ALD processing chamber 116 are all sized and shaped to allow the transfer of process kit items between the transfer chamber 106 and the mask chamber 118, CVD processing chambers 110, 112, and ALD processing chamber 116.
The mask chamber 118 has a door 130 and doorway 131 on the side of the mask chamber 118 opposite the slit valve opening 129 of the transfer chamber 106. The doorway is sized and shaped to allow the transfer of masks and other process tools into and out to the mask chamber 118. The door 130 is capable of forming an air-tight seal over the doorway 131 when closed. The mask chamber 118 is sized and shaped to allow any process kit item to be completely contained within the mask chamber 118 with both the door 130 closed and the slit valve 128 leading to the transfer chamber 106 closed. That is, the mask chamber 118 is sized and shaped such that any process kit item can be moved from the transfer chamber 106 into the mask chamber 118 and the slit valve 128 can be closed without the door 130 of the mask chamber 118 being opened.
For simplicity and ease of description, an exemplary coating process performed within the processing system 100 will now be described. The exemplary coating process is controlled by a process controller, which may be a computer or system of computers that may be located at the control station 114.
Referring to FIG. 1, the exemplary processing of a substrate optionally begins with the handling robot 108 retrieving a mask from the mask chamber 118 and placing the mask in the ALD processing chamber 116. Placing a mask in the ALD processing chamber 116 is optional because a mask may be left in the ALD processing chamber 116 from earlier processing, and the same mask may be used in processing multiple substrates. Similarly, the handling robot 108 may optionally retrieve other masks from the mask chamber 118 and place the masks in the first and second CVD processing chambers 110 and 112. In placing masks within the first and second CVD processing chambers 110, 112 and the ALD processing chamber 116, the appropriate slit valves 122, 124, 126, 128 between the chambers may be opened and closed.
Next, the handling robot 108 retrieves a substrate from the load-lock 104 and places the substrate in the first CVD processing chamber 110. The process controller controls valves, actuators, and other components of the processing chamber to perform the CVD processing. The process controller causes the slit valve 122 to be closed, isolating the first CVD processing chamber 110 from the transfer chamber 106. The process controller also causes a substrate support member, or susceptor, to position the substrate for CVD processing. If the mask was not placed into the correct processing position by the handling robot, then the process controller may activate one or more actuators to position the mask. Alternatively or additionally, the susceptor may also position the mask for processing. The mask is used to mask off certain areas of the substrate and prevent deposition from occurring on those areas of the substrate.
The process controller now activates valves to start the flow of precursor and other gases into the first CVD processing chamber 110. The precursor gases may include silane SiH₄, for example. The process controller controls heaters, plasma discharge components, and the flow of gases to cause the CVD process to occur and deposit layers of materials on the substrate. In one embodiment, the deposited layer may be silicon nitride SiN, although embodiments of the disclosure are not limited to this material. As noted above, embodiments of the disclosure may also be used to perform PECVD. The CVD process in the exemplary processing of the substrate is continued until the deposited layer reaches the required thickness. In one exemplary embodiment, the required thickness is 5000 to 10000 Angstroms (500 to 1000 nm).
When the CVD process in the first CVD processing chamber 110 is complete, the process controller causes the first CVD processing chamber 110 to be evacuated and then controls the susceptor to lower the substrate to a transfer position. The process controller also causes the slit valve 122 between the first CVD processing chamber 110 and the transfer chamber 106 to be opened and then directs the handling robot 108 to retrieve the substrate from the first CVD processing chamber 110. The process controller then causes the slit valve 122 between first CVD processing chamber 110 and the transfer chamber 106 to be closed.
Next, the process controller causes the slit valve 126 between the transfer chamber 106 and the ALD processing chamber 116 to be opened. The handling robot 108 places the substrate in the ALD processing chamber 116, and the process controller causes the slit valve 126 between the transfer chamber 106 and the ALD processing chamber 116 to be closed. The process controller also causes a substrate support member, or susceptor, to position the substrate for ALD processing. If the mask was not placed into the correct processing position by the handling robot, then the process controller may activate one or more actuators to position the mask. Alternatively or additionally, the susceptor may position the mask for processing. The mask is used to mask off certain areas of the substrate and prevent deposition from occurring on those areas of the substrate.
The process controller now activates valves to start the flow of precursor and other gases into the ALD processing chamber 116. The particular gas or gases that are used depend upon the process or processes to be performed. The gases can include trimethylaluminium (CH₃)₃Al (TMA), nitrogen N₂, and oxygen O₂, however, the gases are not so limited and may include one or more precursors, reductants, catalysts, carriers, purge gases, cleaning gases, or any mixture or combination thereof. The gases may be introduced into the ALD processing chamber from one side and flow across the substrate. Depending on requirements of the processing system, the process controller may control valves such that only one gas is introduced into the ALD processing chamber at any particular instant of time.
The process controller also controls a power source capable of activating the gases into reactive species and maintaining the plasma of reactive species to cause the reactive species to react with and coat the substrate. For example, radio frequency (RF) or microwave (MW) based power discharge techniques may be used. The activation may also be generated by a thermally based technique, a gas breakdown technique, a high intensity light source (e.g., UV energy), or exposure to an x-ray source. In the exemplary process, oxygen is activated into a plasma, and the plasma reacts with and deposits a layer of oxygen on the substrate. The process controller then causes TMA to flow across the substrate, and the TMA reacts with the layer of oxygen on the substrate, forming a layer of aluminum oxide on the substrate. The process controller causes repetition of the steps of flowing oxygen, activating oxygen into a plasma, and flowing TMA to form additional layers on the substrate. The process controller continues repeating the described steps until the deposited layer of aluminum oxide is the required thickness. In one exemplary embodiment, the required thickness is 500 to 700 Angstroms (fifty to seventy nm).
When the ALD process in the ALD processing chamber 116 is complete, the process controller causes the ALD processing chamber 116 to be evacuated and then controls the susceptor to lower the substrate to a transfer position. The process controller also causes the slit valve 126 between the ALD processing chamber 116 and the transfer chamber 106 to be opened and then directs the handling robot 108 to retrieve the substrate from the ALD processing chamber 116. The process controller then causes the slit valve 126 between ALD processing chamber 116 and the transfer chamber 106 to be closed.
Still referring to FIG. 1, next, the process controller causes the slit valve 124 between the transfer chamber 106 and the second CVD processing chamber 112 to be opened. The handling robot 108 places the substrate in the second CVD processing chamber 112, and the process controller causes the slit valve 124 between the transfer chamber 106 and the second CVD processing chamber 112 to be closed. Processing in the second CVD processing chamber 112 is similar to the processing in the first CVD processing chamber 110 described above. In the exemplary processing of the substrate, the CVD process performed in the second CVD processing chamber 112 is continued until the deposited layer reaches the desired thickness. In one exemplary embodiment, the desired thickness is 5000 to 10000 Angstroms (500 to 1000 nm).
Thus, when the process in the second CVD processing chamber 112 is complete, the substrate will be coated with a first layer of SiN that is 5000 to 10000 Angstroms thick, a layer of Al₂O₃that is 500 to 700 Angstroms thick, and a second layer of SiN that is 5000 to 10000 Angstroms thick. The layer of Al₂O₃is believed to lower the water vapor transfer rate through the encapsulation layer, as compared to SiN alone, thus improving the reliability of the encapsulation, as compared to encapsulating with SiN alone.
In the exemplary process described above with reference to FIG. 1, each of the CVD processing chambers 110, 112 and the ALD processing chamber 116 is loaded with a mask. Alternatively, the processing system 100 may perform a process wherein a mask moves with a substrate from processing chamber to processing chamber. That is, in a second exemplary process, a substrate and mask are placed (simultaneously or individually) in the first CVD processing chamber 110, and the slit valve 122 between the transfer chamber 106 and the first processing chamber 110 is closed. A CVD process is then performed on the substrate. The substrate and mask are then moved (simultaneously or individually) into the ALD processing chamber 116, and the slit valve 126 between the transfer chamber and the ALD processing chamber 116 is closed. An ALD process is then performed on the substrate. The substrate and mask are then moved (simultaneously or individually) into the second CVD processing chamber 112. A CVD process is then performed on the substrate, and the substrate and mask are then removed from the second CVD processing chamber 112. The substrate may be removed from the processing system 100, if complete, and the mask may be used for processing a new substrate or removed from the processing system 100 for cleaning, for example.
FIG. 2 is a partial cross sectional side view showing an illustrative ALD processing chamber 200 with a process kit 250 in processing position, according to embodiments of the present disclosure. The process kit is described in greater detail below with reference to FIGS. 4 and 5. The ALD processing chamber shown in FIG. 2 is similar to the ALD processing chamber 116 shown in FIG. 1. In one embodiment, the processing chamber 200 includes a chamber body 202, a lid assembly 204, a substrate support assembly 206, a process gas inlet assembly (see FIG. 3) and a pumping port assembly (see FIG. 3). The lid assembly 204 is disposed at an upper end of the chamber body 202, and the substrate support assembly 206 is at least partially disposed within the chamber body 202.
The chamber body 202 includes a slit valve opening 208 formed in a sidewall thereof to provide access to the interior of the processing chamber 200. As described above with reference to FIG. 1, the slit valve opening 208 is selectively opened and closed to allow access to the interior of the chamber body 202 by a handling robot (see FIG. 1).
In one or more embodiments, the chamber body 202 includes one or more apertures (not shown) that are in fluid communication with a vacuum system (e.g., a vacuum pump). The apertures provide an egress for gases within the processing chamber. The vacuum system is controlled by a process controller to maintain a pressure within the ALD processing chamber suitable for the ALD process. In one embodiment of the present disclosure, the pressure in the ALD processing chamber is maintained (by, e.g., a process controller) at a pressure of 500 to 700 mTorr.
The lid assembly 204 may include one or more differential pump and purge assemblies 220. The differential pump and purge assemblies are mounted to the lid assembly with bellows 222. The bellows 222 allow the pump and purge assemblies 220 to move vertically with respect to the lid assembly 204 while still maintaining a seal against gas leaks. When the process kit 250 is raised into a processing position, a compliant first seal 286 and a compliant second seal 288 on the process kit 250 are brought into contact with the differential pump and purge assemblies 220. The first and second seals 286, 288 are compressed when the process kit 250 is in the processing position, and the differential pump and purge assemblies 220 can move to maintain the desired compression force on the first and second seals 286, 288. The first and second seals 286, 288 may be made, for example, from a rubber or plastic material that is compatible with exposure to the process gases and effluent. The differential pump and purge assemblies 220 are connected with a vacuum system (not shown) and maintained at a low pressure. When processing is occurring in the ALD processing chamber 200, the vacuum system (not shown) connected with the differential pump and purge assemblies 220 is controlled (by, e.g., a process controller) to draw a vacuum at a pressure equal to or lower than the pressure of the ALD processing chamber 200. For example, when processing is occurring and pressure in the ALD processing chamber 200 is being maintained at 500 to 700 mTorr (see above), the differential pump and purge assemblies 220 are drawing a vacuum at 400 to 500 mTorr. By drawing a vacuum at a pressure lower than the pressure in the ALD processing chamber 200, the differential pump and purge assemblies 220 can prevent any gases that leak past the seals on the process kit 250 from entering the ALD processing chamber 200. If there are leaks in the first and second seals 286, 288, the lower pressure within the differential pump and purge assemblies 220 causes gases within the ALD processing chamber 200 to leak into the differential pump and purge assemblies 220, rather than gases leaking from the differential pump and purge assemblies 220 into the ALD processing chamber 200.
The processing chamber 200 may include a valve block assembly (not shown). The valve block assembly comprises a set of valves and controls the flow of the various gases (e.g., process gases, carrier gases, and purge gases) into the processing chamber 200.
Still referring to FIG. 2, the lid assembly 204 includes a radio frequency (RF) cathode 210 that can generate a plasma of reactive species within the processing chamber 200 and/or within the process kit 250 (see below with reference to FIG. 4). Temperature of the RF cathode 210 is controlled (by, e.g., a process controller) during processing in the ALD processing chamber 200 to influence temperature of the process kit 250 and substrate 232 and improve performance of the ALD processing. The temperature of the RF cathode 210 may be measured by a pyrometer (not shown), for example, or other sensor in the ALD processing chamber 200. The RF cathode 210 may be heated by electric heating elements (not shown), for example, and cooled by circulation of cooling fluids, for example. Any power source capable of activating the gases into reactive species and maintaining the plasma of reactive species may be used. For example, radio frequency (RF) or microwave (MW) based power discharge techniques may be used. The activation may also be generated by a thermally based technique, a gas breakdown technique, a high intensity light source (e.g., UV energy), or exposure to an x-ray source.
Still referring to FIG. 2, the substrate support assembly 206 can be at least partially disposed within the chamber body 202. The substrate support assembly can include a substrate support member or susceptor 230 to support a substrate 232 for processing within the chamber body. According to embodiments of the present disclosure, the susceptor can also support (see FIG. 4) the process kit 250. The susceptor can be coupled to a substrate lift mechanism (not shown) through a shaft 224 or shafts 224 which extend through one or more openings 226 formed in a bottom surface of the chamber body. The substrate lift mechanism can be flexibly sealed to the chamber body by a bellows 228 that prevents vacuum leakage from around the shafts. The substrate lift mechanism allows the susceptor 230 to be moved vertically within the ALD processing chamber 200 between a lower robot entry position, as shown, and processing, process kit transfer, and substrate transfer positions. In some embodiments, the substrate lift mechanism moves between fewer positions than those described.
In one or more other embodiments, the susceptor 230 has a flat, rectangular surface or a substantially flat, rectangular surface, as required by the shape of the substrate and other processing requirements. In one or more embodiments, the substrate 232 may be secured to the susceptor using a vacuum chuck (not shown), an electrostatic chuck (not shown), or a mechanical clamp (not shown). The temperature of the susceptor 230 may be controlled (by, e.g., a process controller) during processing in the ALD processing chamber 200 to influence temperature of the substrate 232 and the process kit 250 and improve performance of the ALD processing. The susceptor 230 may be heated by, for example, electric heating elements (not shown) within the susceptor 230. The temperature of the susceptor may be determined by pyrometers (not shown) in the processing chamber 200, for example.
Still referring to FIG. 2, the susceptor 230 can include one or more bores 234 through the susceptor to accommodate one or more lift pins 236. Each lift pin is typically constructed of ceramic or ceramic-containing materials, and is used for substrate-handling and transport. Each lift pin 236 is mounted so that they may slide freely within a bore 234. In one aspect, each bore is lined with a ceramic sleeve to help the lift pins to freely slide. Each lift pin is moveable within its respective bore 234 by contacting the chamber body 202 when the support assembly 206 is lowered, as illustrated in FIG. 2. The support assembly 206 is movable such that the upper surface of the lift pin 236 can be located above the substrate support surface 238 of the susceptor 230 when the support assembly 206 is in a lower position. Conversely, the upper surface of the lift pins 236 is located below the upper surface 238 of the susceptor 230 when the support assembly 206 is in a raised position. Thus, part of each lift pin 236 passes through its respective bore 234 in the susceptor 230 when the support assembly 206 moves from a lower position to an upper position, and vice-versa.
When contacting the chamber body 202, the lift pins 236 push against a lower surface of the substrate 232, lifting the substrate off the susceptor 230. Conversely, the susceptor 230 may raise the substrate 232 off of the lift pins 236. The lift pins 236 can include enlarged upper ends or conical heads to prevent the lift pins 236 from falling out of the susceptor 230. Other pin designs can also be utilized and are well known to those skilled in the art.
In one embodiment, one or more of the lift pins 236 include a coating or an attachment disposed thereon that is made of a non-skid or highly frictional material to prevent the substrate 232 from sliding when supported thereon. A preferred material is a heat-resistant, polymeric material that does not scratch or otherwise damage the backside of the substrate 232, which may create contaminants within the processing chamber 200.
In some embodiments, the susceptor includes process kit insulation buttons 237 that may include one or more compliant seals 239. The process kit insulation buttons 237 may be used to carry the process kit 250 on the susceptor 230. The one or more compliant seals 239 in the process kit insulation buttons 237 are compressed when the susceptor lifts the process kit 250 into the processing position (see discussion of processing below, with reference to FIGS. 1-5). The process kit insulation buttons 237 may be made of aluminum oxide Al₂O₃or another material with a high electrical resistance to insulate the susceptor from electrical charges induced on the process kit due to the processing.
Referring back to FIG. 2, the susceptor 230 can be moved vertically within the chamber body 202 so that the susceptor 230 contacts the process kit 250 (see FIG. 4). The process kit 250 may be on the susceptor 230 during part of the movement of the process kit 250 into or out of the processing chamber 200. A distance between the process kit 250 and the RF cathode 210 can be controlled. An optical or other sensor (not shown), for example, can provide information concerning the position of the susceptor 230 within the chamber 200.
FIG. 3 is a partial cross-sectional view from the front of the ALD processing chamber 200 illustrated in FIG. 2. That is, FIG. 3 shows the same ALD processing chamber as shown in FIG. 2, but from a different point of view. Visible in FIG. 3 are the process gas inlet assembly 310 and the pumping port assembly 330.
The process gas inlet assembly 310 supplies process gases to the ALD processing chamber 200. Process gases used may include trimethylaluminium (TMA) Al₂(CH₃)₆, oxygen O₂, and nitrogen N₂. The process gases may be supplied in a continuous flow or may be pulsed, either individually or together. The process gas inlet assembly 310 comprises one or more inlet pipes 312, a bellows 314, an inlet manifold 316, an inlet contact surface 318, and seals 320.
Process gases are supplied from a process gas source (e.g., a tank or pipeline, not shown) to the one or more inlet pipes 312. The flow of process gases is controlled by, for example, a process controller (not shown) controlling the operation of one or more valves in a valve block (not shown). The one or more inlet pipes 312 are connected with the ALD processing chamber 200 by a bellows 314. The bellows 314 allows the one or more inlet pipes 312 and inlet manifold 316 to move with respect to the ALD processing chamber 200 (e.g., when the process kit 250 contacts the inlet contact surface 318 as shown in FIG. 4) without allowing air to leak into the ALD processing chamber 200. The process gases flow through the inlet pipe 312 and into the inlet manifold 316.
The process gases flow through the inlet manifold 316, through one or more channels 322 in the inlet contact surface 318, and into one or more inlet channels 354 in the process kit 250 (see also FIG. 4). The inlet contact surface 318 may be made from any material compatible with exposure to the process gases and effluent gases, for example, polytetrafluoroethylene (PTFE). One or more seals 320 seal the joint between the inlet manifold 316 and the inlet contact surface 318 to inhibit process gases from leaking into the ALD processing chamber 200.
Effluent gases, which comprise reaction products and unreacted process gases, are pumped out of one or more outlet channels 356 in the process kit 250 via the pumping port assembly 330. The pumping port assembly comprises one or more outlet pipes 332, a bellows 334, an outlet manifold 336, an outlet contact surface 338, and seals 340.
Effluent gases from within the process kit 250 (see the description of ALD processing with reference to FIG. 4 below) exit the process kit 250 via one or more outlet channels 356. The effluent gases flow through the outlet channels 356 and into one or more channels 342 in the outlet contact surface 338 (see also FIG. 4).
The effluent gases flow through the channels 342 in the outlet contact surface 338 and into the outlet manifold 336. The outlet contact surface 338 may be made from any compliant material compatible with exposure to the process gases and effluent gases, for example, polytetrafluoroethylene (PTFE). One or more seals 340 seal the joint between the outlet contact surface 338 and the outlet manifold 336 to inhibit effluent gases from leaking into the ALD processing chamber 200.
The effluent gases flow through outlet manifold 336 and into the one or more outlet pipes 332. The bellows 334 allows the one or more outlet pipes 332 and outlet manifold 336 to move with respect to the ALD processing chamber 200 (e.g., when the process kit 250 contacts the outlet contact surface 338 as shown in FIG. 4) without allowing air to leak into the ALD processing chamber 200.
The effluent gases are pumped out of the one or more outlet pipes 332 by a vacuum system (not shown).
FIGS. 4A and 4B show partial cross-sectional front views of the process kit 250 and the susceptor 230 and lid assembly 204 of the ALD processing chamber 200. FIG. 4B shows an enlarged view of the indicated portion of FIG. 4A to more clearly present details. The illustrated components are in a processing position, with a substrate 232 positioned for performing ALD.
According to embodiments of the present disclosure, the process kit 250 may comprise a mask 458, a window 460, and a frame assembly 470. The process kit 250 has at least one inlet channel 354 connecting a first outer surface 402 of the frame assembly 470 with a first inner surface 404 of the frame assembly 470 that is between the mask 458 and the window 460. The process kit 250 also has at least one outlet channel 356 connecting a second outer surface 410 with a second inner surface 412 of the frame assembly 470 that is between the mask 458 and the window 460. As illustrated in FIG. 4A, when the process kit 250 is in a processing position, the at least one inlet channel 354 is aligned with the one or more channels 322 in the inlet contact surface 318 of the process gas inlet assembly 310. Also, when the process kit 250 is in a processing position, the at least one outlet channel 356 is aligned with the one or more channels 342 in the outlet contact surface 338 of the pumping port assembly 330.
In some embodiments of the present disclosure, the frame assembly 470 may comprise an upper member 472, a window clamping member 474, a middle member 476, and a lower member 478. In embodiments of the process kit 250 comprising a window clamping member 474, the window 460 is clamped between the window clamping member 474 and the upper member 472.
Referring to FIG. 4A and FIG. 4B, in some embodiments of the present disclosure, the process kit 250 further comprises at least one window seal 480, at least one seal 482 surrounding an opening of the inlet channel 354, at least one seal 484 surrounding an opening of the outlet channel 356, a first seal 286 on the upper surface of the frame assembly 470, a second seal 288 on the upper surface of the frame assembly 470, and one or more seals 490. In embodiments comprising a window seal 480, the window 460 is held by the window seal 480 and the window clamping member 474, with the window 460 between the window seal 480 and the window clamping member 474. The window seal 480, at least one seal 482 surrounding an opening of the inlet channel 354, at least one seal 484 surrounding an opening of the outlet channel 356, first seal 286, second seal 288, and seals 490 may all be made of a compliant material (e.g., rubber, PTFE) that is compatible with exposure to the processing gases and effluent gases.
The mask 458 and lower member 478 may be made of Invar or other materials that are compatible with exposure to process and effluent gases and have low coefficient of thermal expansion. It is desirable that the mask 458 and the lower member 478 be made from materials with low coefficients of thermal expansion to reduce variations in the locations of the deposited coatings caused by variations in temperature during processing. That is, variations in masked locations caused by temperature variations are reduced, if the mask 458 and a frame member holding the mask 458 (e.g., the frame lower member 478) are made from a material with a low coefficient of thermal expansion.
The upper member 472 and middle member 476 of the frame assembly 470 may be made of aluminum, anodized aluminum, nickel plated aluminum, stainless steel, quartz, or other materials compatible with exposure to the process gases and effluent gases.
During ALD processing in the ALD processing chamber 200, the susceptor 230 positions the substrate 232 just below the mask 458 of the process kit 250. While the susceptor 230 is positioning the substrate 232, the susceptor 230 is also pressing the process kit 250 into contact with the differential pump and purge assemblies 220 (see FIG. 2), the inlet contact surface 318 (see also FIG. 3), and the outlet contact surface 338 (see also FIG. 3). Pressing the process kit into contact with the differential pump and purge assemblies 220 (see FIG. 2), the inlet contact surface 318 (see also FIG. 3), and the outlet contact surface 338 (see also FIG. 3) causes compression of the at least one seal 482 surrounding an opening of the inlet channel 354, at least one seal 484 surrounding an opening of the outlet channel 356, first seal 286, and second seal 288. The at least one seal 482 surrounding an opening of the inlet channel 354, at least one seal 484 surrounding an opening of the outlet channel 356, first seal 286, and second seal 288 all inhibit the leakage of process and/or effluent gases into the processing chamber 200.
In other embodiments of the present disclosure, the process kit 250 is held in position against the differential pump and purge assemblies 220 (see FIG. 2), the inlet contact surface 318 (see also FIG. 3), and the outlet contact surface 338 (see also FIG. 3) by a separate mechanical chuck (not shown), vacuum chuck (not shown), or magnetic chuck (not shown). When held by one of the various chucks, the process kit 250 may be held against the differential pump and purge assemblies 220 (see FIG. 2), the inlet contact surface 318 (see also FIG. 3), and the outlet contact surface 338 (see also FIG. 3) with the various seals 482, 484, 286, 288 compressed, or the process kit 250 may be held in a position without some or all of the various seals 482, 484, 286, 288 being compressed.
FIG. 5 shows a top view of an exemplary process kit 250. As shown, the window 460, window clamping member 474, upper member 472, an opening of an inlet channel 354, and an opening of an outlet channel 356 are visible in the top view of the process kit 250. Also visible are one seal 482 surrounding the opening of the inlet channel 354, one seal 484 surrounding the opening of the outlet channel 356, the first seal 286 on the upper surface of the frame, and the second seal 288 on the upper surface of the frame. Various screws connecting the window clamping member 474 to the upper member 472 are not shown in FIG. 5, so that other features can be seen more clearly.
While the exemplary process kit 250 shown in FIG. 5 has only a single slit-shaped (i.e., having a high length-to-width ratio, e.g., 4 to 1) opening to the inlet channel 354, the disclosure is not so limited. While the illustrated slit-shaped opening has sharp corners, embodiments of the disclosure may have slit-shaped openings with rounded ends. In addition, embodiments of the present disclosure may use openings of many other shapes, for example, square, ovoid, and rectangular openings to the inlet channel 354 may be used. Also, embodiments of the disclosure may use more than one inlet channel 354, with each inlet channel 354 having a corresponding opening or openings. Each opening may be surrounded by a seal 482, or more than one opening may be surrounded by one seal 482.
Similarly, while the exemplary process kit 250 shown in FIG. 5 has only a single slit-shaped opening to the outlet channel 356, the disclosure is not so limited. While the illustrated slit-shaped opening has sharp corners, embodiments of the disclosure may have slit-shaped openings with rounded ends. In addition, embodiments of the present disclosure may use openings of many shapes, for example, square, ovoid, and rectangular openings to the outlet channel 356 may be used. Also, embodiments of the disclosure may use more than one outlet channel 356, with each outlet channel 356 having a corresponding opening or openings. Each opening may be surrounded by a seal 484, or more than one opening may be surrounded by one seal 484.
The window 460 of the process kit 250 may be made of quartz, for example, or another material that both allows radiant energy (e.g., infrared rays, ultraviolet rays, or RF energy) to penetrate into the process kit 250 and is compatible with exposure to process gases and effluent gases.
The window clamping member 474 may be made of aluminum oxide Al₂O₃or another material that can clamp the quartz or other material of the window 460 without being damaged by exposure to the energy (e.g., infrared rays, ultraviolet rays, or RF energy) used to convert process gases to reactive species (e.g., RF energy from the RF cathode 210).
The various seals 482, 484, 286, and 288 may be made of PTFE, rubber, or another compliant material that is compatible with exposure to process gases and effluent gases.
In order to further describe the process kit 250, an exemplary ALD process performed using the process kit 250 in the ALD processing chamber 200 will now be described, with reference to FIGS. 1-5.
In the exemplary ALD process, a process kit 250 is present in the ALD processing chamber 200 (see FIG. 2) when the handling robot 108 (see FIG. 1), under the direction of a process controller (not shown), places a substrate 232 on the lift pins 236 in the ALD processing chamber 200 (see FIG. 2). The handling robot 108 places the substrate 232 in the ALD processing chamber 200 by means of a blade or other robotic tool that the handling robot 108 inserts into the ALD processing chamber 200 via the slit valve 208 (see FIG. 2).
The process controller then directs the substrate support assembly 206 (see FIG. 2) to raise the substrate 232 into a processing position below the mask 458 of the process kit 250 (see FIG. 4A). When the substrate 232 is in the process position, the process controller starts the flow of process gases into the ALD processing chamber 200 via the process gas inlet assembly 310 (see FIG. 3). The process gases may be flowed as a mixture of multiple precursors (e.g. TMA and O₂) and carrier gases (e.g., Helium), or, if time separated ALD (TS-ALD) is to be performed, then each precursor gas (possibly mixed with a carrier gas) flows in separate pulses from each other precursor gas source.
The process gases flow through the inlet manifold 316, through one or more channels 322 in the inlet contact surface 322, and into one or more inlet channels 354 of the process kit (see FIG. 3). The process gases flow through the inlet channels 354 and into the volume between the window 460 and mask 458 of the process kit 250 (see FIG. 4A). While the process gases are in the volume between the window 460 and mask 458, the process gases may be activated into reactive species (e.g., plasma) by the RF cathode 210 (or other means of activating the process gases) of the ALD processing chamber 200. The process gases can be activated within the process kit 250, because the window 460 allows activating rays (or other energy) to penetrate into the process kit 250. For example, oxygen can be activated into a plasma within the volume between the window 460 and the mask 458.
The process gases and any activated species of the process gases react with and coat the substrate 232. For example, a plasma of oxygen may react with and coat the substrate 232. In the example, TMA may then react with the oxygen coating on the substrate, forming a layer of aluminum oxide on the substrate. The mask 458 controls the exposure of the substrate so that coatings of materials are deposited in desired locations of the substrate 232, and not deposited in areas of the substrate 232 where the coatings are not desired.
Effluent gases (e.g., reaction products and unreacted process gases) are pumped out of the process kit 250 via one or more outlet channels 356 (see FIGS. 3 and 4). Effluent gases flow from the one or more outlet channels 356 into the one or more channels 342 in the outlet contact surface, through the outlet manifold 336, and into the one or more outlet pipes 332, as described above.
Some process gases may leak past the one or more seals 482 surrounding the opening of the inlet channel 354. Process gases leaking past the seal(s) 482 are inhibited from moving into other parts of the ALD processing chamber 200 by the first seal 286 and second seal 288 on the upper surface of the frame of the process kit 250 (see FIG. 5). In addition, process gases leaking past the seal(s) 482 may be pumped out of the ALD processing chamber 200 by the differential pump and purge assemblies 220 (see FIG. 2).
Some effluent gases may leak past the one or more seals 484 surrounding the opening of the outlet channel 356. Effluent gases leaking past the seal(s) 484 are inhibited from moving into other parts of the ALD processing chamber 200 by the first seal 286 and second seal 288 on the upper surface of the frame of the process kit 250 (see FIG. 5). In addition, effluent gases leaking past the seal(s) 484 may be pumped out of the ALD processing chamber 200 by the differential pump and purge assemblies 220 (see FIG. 2).
FIGS. 6A, 6B, and 6C show front views (i.e., from the same point of view as FIG. 3) of positions of a process kit and substrate during the placement of a process kit and a substrate in the exemplary ALD processing chamber 200, in preparation for performing processing. FIG. 6A shows the position of the process kit 250 immediately after the process kit 250 has been placed in the processing chamber 200. The process kit 250 is placed in the processing chamber 200 by the handling robot 108 (see FIG. 1) via the slit valve opening 208 (see FIG. 2). The process kit 250 is placed on process kit alignment pins 602 by the handling robot 108. The process kit alignment pins 602 have ends of conical or other shape that help to align the process kit 250 with the processing position of the process kit 250.
The process kit alignment pins 602 are connected with a process kit lift mechanism (not shown) that can raise and lower the process kit alignment pins 602. After the handling robot has placed the process kit 250 on the process kit alignment pins 602, the process kit lift mechanism raises the process kit alignment pins 602, which raise the process kit 250.
FIG. 6B shows the process kit alignment pins 602 and process kit 250 in a raised position. The raised position shown in FIG. 6B may be referred to as a substrate loading position. When the process kit alignment pins 602 and process kit 250 are in the substrate loading position, the handling robot (see FIG. 1) may place a substrate 232 within the processing chamber 200 via the slit valve opening 208 (see FIG. 2). The substrate 232 is placed on the lift pins 236. The handling robot 108 then withdraws the tool (e.g., a blade) used to place the substrate within the processing chamber 200, and the process controller causes the slit valve 208 to be closed. After the handling robot 108 has withdrawn the tool from the processing chamber 200, the substrate lift mechanism (not shown) can raise the one or more shafts 224 (see FIG. 2), which raise the susceptor 230.
FIG. 6C shows the process kit 250, susceptor 230, and substrate 232 in the processing position. As shown in more detail in FIGS. 4 and 4A, the process kit 250 is lifted into the processing position by the susceptor 230. The process kit 250 is in contact with the inlet contact surface 318 and the outlet surface contact 338 when the process kit 250 is in the processing position.
When processing is complete, the substrate lift mechanism (not shown) lowers the susceptor 230. The process kit 250 comes to rest on the process kit alignment pins 602, and the substrate 232 comes to rest on the lift pins 236, as shown in FIG. 6B.
FIG. 7 is a partial cross-sectional view from the front of an exemplary ALD processing chamber 700 illustrated. The exemplary ALD processing chamber 700 is similar to the exemplary processing chamber 200 illustrated in FIG. 2. Visible in FIG. 7 are two pumping port assemblies 730 a, 730 b.
Process gas is supplied to the ALD processing chamber 700 via one or more inlets 702. The process gases may enter a plenum 704 before the process gases flow into the interior of the ALD processing chamber 700. The process gases may be supplied in a continuous flow or may be pulsed, either individually or together. Some or all of the process gases may be activated into a reactive species (e.g., a plasma) in the plenum 704 before they flow into the interior of the ALD processing chamber.
Process gases are supplied from a process gas source (e.g., a tank or pipeline, not shown) to the one or more inlet pipes 712 a, 712 b. The flow of process gases is controlled by, for example, a process controller (not shown) controlling the operation of one or more valves in a valve block (not shown).
The process gases flow through the plenum 704, through the one or more inlets 702, and into one or more inlet channels 754 in a process kit 750 (see also FIG. 8). One or more seals 720 seal the joint between the inlet 702 and the inlet channel 754 to inhibit process gases from leaking into the ALD processing chamber 200.
Effluent gases, which comprise reaction products and unreacted process gases, are pumped out of one or more outlet channels 756 a, 756 b in the process kit 750 via the pumping port assemblies 730 a, 730 b. The pumping port assemblies 730 a, 730 b comprise one or more outlet pipes 732 a, 732 b, bellows 734 a, 734 b, outlet manifolds 736 a, 736 b, outlet contact surfaces 738 a, 738 b, and seals 740 a, 740 b.
Effluent gases from within the process kit 750 (see the description of ALD processing with reference to FIG. 4 above) exit the process kit 750 via one or more outlet channels 756 a, 756 b. The effluent gases flow through the outlet channels 756 a, 756 b and into one or more channels 742 a, 742 b in the outlet contact surfaces 738 a, 738 b.
The effluent gases flow through the channels 742 a, 742 b in the outlet contact surfaces 738 a, 738 b and into the outlet manifolds 736 a, 736 b. The outlet contact surfaces 738 a, 738 b may be made from any compliant material compatible with exposure to the process gases and effluent gases, for example, polytetrafluoroethylene (PTFE). One or more seals 740 a, 740 b seal the joints between the outlet contact surfaces 738 a, 738 b and the outlet manifolds 736 a, 736 b to inhibit effluent gases from leaking into the ALD processing chamber 700.
The effluent gases flow through outlet manifolds 736 a, 736 b and into the one or more outlet pipes 732 a, 732 b. The bellows 734 a, 734 b allow the one or more outlet pipes 732 a, 732 b and outlet manifolds 736 a, 736 b to move with respect to the ALD processing chamber 700 (e.g., when the process kit 750 contacts the outlet contact surfaces 738 a, 738 b as shown) without allowing air to leak into other portions of the ALD processing chamber 700.
The effluent gases are pumped out of the one or more outlet pipes 732 a, 732 b by a vacuum system (not shown).
FIG. 8 shows a top view of an exemplary process kit 750. The exemplary process kit 750 has some similarity to the exemplary process kit 250 illustrated in FIG. 2, and similar terminology is used to describe similar components. As shown, two windows 760 a, 760 b, window clamping members 774 a, 774 b, upper member 772, an opening of an inlet channel 754, and two openings of outlet channels 756 a, 756 b are visible in the top view of the process kit 750. Also visible are one seal 782 surrounding the opening of the inlet channel 754, two seals 784 a, 784 b surrounding the openings of the outlet channels 756 a, 756 b, and a first seal 786 on the upper surface of the frame. It is to be noted that the windows 760 a, 760 b and window clamping members 754 a, 754 b are optional. If the windows 760 a, 760 b and window clamping members 754 a, 754 b are not present, then the upper member 772 may enclose the interior of the process kit 750. Various screws connecting the window clamping members 774 a, 774 b to the upper member 772 are not shown in FIG. 8, so that other features can be seen more clearly.
While the exemplary process kit 750 shown in FIG. 8 has only a single slit-shaped (i.e., having a high length-to-width ratio, e.g., 4 to 1) opening to the inlet channel 754, the disclosure is not so limited. While the illustrated slit-shaped opening has sharp corners, embodiments of the disclosure may have slit-shaped openings with rounded ends. In addition, embodiments of the present disclosure may use openings of many other shapes, for example, square, ovoid, and rectangular openings to the inlet channel 754 may be used. Also, embodiments of the disclosure may use more than one inlet channel 754, with each inlet channel 754 having a corresponding opening or openings. Each opening may be surrounded by a seal 782, or more than one opening may be surrounded by one seal 782.
Similarly, while the exemplary process kit 750 shown in FIG. 8 has two single slit-shaped openings to the outlet channels 756 a, 756 b, the disclosure is not so limited. While the illustrated slit-shaped openings have sharp corners, embodiments of the disclosure may have slit-shaped openings with rounded ends. In addition, embodiments of the present disclosure may use openings of many shapes, for example, square, ovoid, and rectangular openings to the outlet channels 756 a, 756 b may be used. Also, embodiments of the disclosure may use more than one outlet channel 756 a, 756 b, with each outlet channel 756 a, 756 b having a corresponding opening or openings. Each opening may be surrounded by a seal 784 a, 784 b, or more than one opening may be surrounded by one seal 784 a, 784 b.
The windows 760 a, 760 b of the process kit 750 may be made of quartz, for example, or another material that both allows radiant energy (e.g., infrared rays, ultraviolet rays, or RF energy) to penetrate into the process kit 750 and is compatible with exposure to process gases and effluent gases.
The window clamping members 774 a, 774 b may be made of aluminum oxide Al₂O₃or another material that can clamp the quartz or other material of the windows 760 a, 760 b without being damaged by exposure to the energy (e.g., infrared rays, ultraviolet rays, or RF energy) used to convert process gases to reactive species.
The various seals 782, 784 a, 784 b, and 786 may be made of PTFE, rubber, or another compliant material that is compatible with exposure to process gases and effluent gases.
The process controller described above with reference to FIG. 1 can operate under the control of a computer program stored on a hard disk drive of a computer. For example, the computer program can dictate the process sequencing and timing, mixture of gases, chamber pressures, RF power levels, susceptor positioning, slit valve opening and closing, and other parameters of a particular process.
To provide a better understanding of the foregoing discussion, the above non-limiting examples are offered. Although the examples may be directed to specific embodiments, the examples should not be interpreted as limiting the disclosure in any specific respect.
Unless otherwise indicated, all numbers expressing quantities of ingredients, properties, reaction conditions, and so forth, used in the specification and claims are to be understood as approximations. These approximations are based on the desired properties sought to be obtained by the present disclosure, and the error of measurement, and should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Further, any of the quantities expressed herein, including temperature, pressure, spacing, molar ratios, flow rates, and so on, can be further optimized to achieve the desired layer and particle performance.
While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

1. A process kit for use in an atomic layer deposition (ALD) chamber, said process kit comprising:

a window;

a mask disposed parallel to the window; and

a frame connected with the window and the mask, wherein said frame has at least one inlet channel connecting a first outer surface of the frame with a first inner surface of the frame, said first inner surface being between the window and the mask, and wherein said frame has at least one outlet channel connecting a second outer surface of the frame with a second inner surface of the frame, said second inner surface of the frame being between the window and the mask.

2. The process kit of claim 1, wherein the window comprises quartz.

3. The process kit of claim 1, wherein the mask comprises Invar.

4. The process kit of claim 1, wherein the frame comprises an upper member, a window clamping member, a middle member, and a lower member connected with the mask, wherein the window is held between said window clamping member and said upper member, said upper member is connected with said middle member, and said middle member is connected with said lower member.

5. The process kit of claim 4, wherein the upper member comprises a window seal, and the window is held between said window seal and the window clamping member.

6. The process kit of claim 1, wherein an opening on the first outer surface into the at least one inlet channel is slit-shaped.

7. The process kit of claim 1, wherein an opening on the second outer surface into the at least one outlet channel is slit-shaped.

8. The process kit of claim 1, further comprising:

at least one seal on the first outer surface of the frame, said at least one seal surrounding an opening of the at least one inlet channel.

9. The process kit of claim 1, further comprising:

at least one seal on the second outer surface of the frame, said at least one seal surrounding an opening of the at least one outlet channel.

10. The process kit of claim 1, further comprising:

at least one inner seal on an upper surface of the frame, said at least one inner seal surrounding the window.

11. An apparatus for processing a substrate, comprising:

a chamber body;

a susceptor;

at least one process kit alignment pin;

at least one process gas inlet;

at least one pumping port; and

a process kit, wherein the process kit comprises a window, a mask disposed parallel to the window, and a frame connected with the window and the mask, wherein said frame has at least one inlet channel connecting a first outer surface of the frame with a first inner surface of the frame, said first inner surface being between the window and the mask, and wherein said frame has at least one outlet channel connecting a second outer surface of the frame with a second inner surface of the frame, said second inner surface of the frame being between the window and the mask.

12. The apparatus of claim 11, wherein the susceptor is operable to lift the process kit into a processing position.

13. The apparatus of claim 12, wherein the at least one inlet channel of the process kit is aligned with the at least one process gas inlet and the at least one outlet channel of the process kit is aligned with the at least one pumping port, when the process kit is in the processing position.

14. The apparatus of claim 11, further comprising:

at least one differential pump and purge assembly.

15. The apparatus of claim 14, further comprising:

a lid assembly, wherein the at least one differential pump and purge assembly is connected with the lid assembly and operable to move with respect to the lid assembly.

16. The process kit of claim 8, wherein the at least one seal comprises rubber.

17. The process kit of claim 9, wherein the at least one seal comprises rubber.

18. The process kit of claim 10, wherein the at least one inner seal comprises rubber.

19. The process kit of claim 10, further comprising:

at least one outer seal on the upper surface of the frame, said at least one outer seal surrounding the at least one inner seal.

20. The process kit of claim 19, wherein the at least one outer seal comprises rubber.