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.
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.
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.
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.
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.
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
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
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 Al2O3 that is 500 to 700 Angstroms thick, and a second layer of SiN that is 5000 to 10000 Angstroms thick. The layer of Al2O3 is 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
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
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
Still referring to
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
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
Referring back to
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
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
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
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
The effluent gases are pumped out of the one or more outlet pipes 332 by a vacuum system (not shown).
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
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
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
In other embodiments of the present disclosure, the process kit 250 is held in position against the differential pump and purge assemblies 220 (see
While the exemplary process kit 250 shown in
Similarly, while the exemplary process kit 250 shown in
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 Al2O3 or 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
In the exemplary ALD process, a process kit 250 is present in the ALD processing chamber 200 (see
The process controller then directs the substrate support assembly 206 (see
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
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
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
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
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.
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
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 712a, 712b. 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
Effluent gases, which comprise reaction products and unreacted process gases, are pumped out of one or more outlet channels 756a, 756b in the process kit 750 via the pumping port assemblies 730a, 730b. The pumping port assemblies 730a, 730b comprise one or more outlet pipes 732a, 732b, bellows 734a, 734b, outlet manifolds 736a, 736b, outlet contact surfaces 738a, 738b, and seals 740a, 740b.
Effluent gases from within the process kit 750 (see the description of ALD processing with reference to
The effluent gases flow through the channels 742a, 742b in the outlet contact surfaces 738a, 738b and into the outlet manifolds 736a, 736b. The outlet contact surfaces 738a, 738b 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 740a, 740b seal the joints between the outlet contact surfaces 738a, 738b and the outlet manifolds 736a, 736b to inhibit effluent gases from leaking into the ALD processing chamber 700.
The effluent gases flow through outlet manifolds 736a, 736b and into the one or more outlet pipes 732a, 732b. The bellows 734a, 734b allow the one or more outlet pipes 732a, 732b and outlet manifolds 736a, 736b to move with respect to the ALD processing chamber 700 (e.g., when the process kit 750 contacts the outlet contact surfaces 738a, 738b 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 732a, 732b by a vacuum system (not shown).
While the exemplary process kit 750 shown in
Similarly, while the exemplary process kit 750 shown in
The windows 760a, 760b 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 774a, 774b may be made of aluminum oxide Al2O3 or another material that can clamp the quartz or other material of the windows 760a, 760b 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, 784a, 784b, 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
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.
Filing Document | Filing Date | Country | Kind |
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PCT/US2015/011956 | 1/20/2015 | WO | 00 |
Number | Date | Country | |
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61929786 | Jan 2014 | US | |
62075794 | Nov 2014 | US | |
62076342 | Nov 2014 | US |