Multi-station processing tools with station-varying support features for backside processing

Abstract

To provide multi-station processing tools with station-varying support features for backside processing.SOLUTION: A first processing station comprises an element 401a including a first support feature 402a, and a second processing station comprises an element 401b including a second support feature 402b. A wafer carrier ring 400 includes a plurality of wafer hold features 406 supporting a wafer or the other substrate. When the wafer carrier ring 400 is carried up for a moving or processing operation between stations, the wafer hold feature 406 is engaged with a lower side of the wafer, and a sufficient number of wafer hold features 406 is disposed at an appropriate interval for stably holding the wafer along with an inner periphery of the wafer carrier ring 400.SELECTED DRAWING: Figure 4A

Description

[Technical field]

[0001] Incorporation by Reference A PCT application is being filed contemporaneously herewith as a part of this application, and each application identified in that contemporaneously filed PCT application to which this application claims benefit or priority is hereby incorporated by reference in its entirety for all purposes. [Background technology]

[0002] The present disclosure relates to a multi-station processing tool for backside processing.

[0003] The background description provided herein is intended to provide a general overview of the contents of the present disclosure. Work by the currently named inventors within the scope of what is described in this Background section, as well as aspects of the description that may not otherwise be regarded as prior art at the time of filing, are not admitted, expressly or impliedly, as prior art against the present disclosure. Summary of the Invention

[0004] In one aspect, a multi-station plasma processing system is provided, the system including a first processing station comprising a first set of support features configured to support a substrate at a first set of positions on a back surface of the substrate when the substrate is processed at the first processing station, and a second processing station comprising a second set of support features configured to hold a substrate at a second set of positions on a back surface of the substrate when the substrate is processed at the second processing station, wherein the first set of positions do not overlap with the second set of positions.

[0005] In another aspect, a multi-station plasma processing system for processing a substrate having a nominal diameter of D is provided, the system including a first processing station having a first set of support features, a second processing station having a second set of support features, and an indexer configured to rotate about a central axis thereby transferring the substrate from the first processing station to the second processing station, the first set of support features having a first diameter of D and having a first set of contact surfaces positioned within a first circular area centered on a first center point of the first processing station, the second set of support features having a second diameter of D and having a second set of contact surfaces positioned within a second circular area centered on a second center point of the second processing station, and a rotational translation of the first center point and the first set of contact surfaces about the central axis such that the rotationally translated first center point is aligned with the second center point results in no overlap between the second set of contact surfaces and the rotationally translated first set of contact surfaces when viewed along the central axis.

[0006] In another aspect, a method for processing a back side of a substrate in a multi-station plasma processing system is provided, the system including a first station with a first set of support features, the system including a second station with a second set of support features, the method including moving the substrate onto the first set of support features and processing the back side of the substrate while the substrate is on the first set of support features, the first set of support features blocking processing of the back side of the substrate at a first set of locations on the back side of the substrate, moving the substrate onto the second set of support features and processing the back side of the substrate while the substrate is on the second set of support features, the second set of support features not blocking processing of the back side of the substrate at the first set of locations on the back side of the substrate. [Brief description of the drawings]

[0007] [Figure 1]FIG. 1 is a schematic diagram of a substrate processing system in accordance with certain disclosed embodiments.

[0008] [Diagram 2] FIG. 2 is a top view of a multi-station processing tool in accordance with certain disclosed embodiments.

[0009] [Diagram 3] FIG. 3 is a schematic diagram of a multi-station processing tool in accordance with certain disclosed embodiments.

[0010] [Figure 4A] FIG. 4A is a perspective view of a support feature multi-station processing tool.

[0011] [Figure 4B] FIG. 4B is a top view of a support feature in a multi-station processing tool.

[0012] [Figure 4C] FIG. 4C is a side view of a support feature in a multi-station processing tool.

[0013] [Diagram 5] FIG. 5 is a schematic diagram of an exemplary control module for controlling a substrate processing system in accordance with certain disclosed embodiments.

[0014] [Figure 6] FIG. 6 illustrates various bottom views of a wafer being processed in a multi-station processing tool in accordance with certain disclosed embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the presented embodiments. The disclosed embodiments may be practiced without some or all of these specific details. In other instances, well-known process operations have not been described in detail so as not to unnecessarily obscure the disclosed embodiments. It will be understood that while the disclosed embodiments will be described in conjunction with specific embodiments, they are not intended to limit the disclosed embodiments.

[0016] Part of this disclosure relates to plasma enhanced chemical vapor deposition (PECVD). PECVD is a type of plasma deposition used to deposit thin films from a gaseous state (i.e., vapor) to a solid state on a substrate, such as a wafer. A PECVD system converts a liquid precursor into a vapor precursor, which is delivered to a chamber. A PECVD system may include a vaporizer that evaporates the liquid precursor in a controlled manner to produce the vapor precursor. Typically, chambers used for PECVD use a ceramic pedestal to support the wafer during processing, which allows processing at high temperatures.

[0017] Most PECVD deposition and other processing to form devices occurs on the front, e.g., top, side of the wafer. As the deposition layers build up, stress may be introduced into the wafer. This stress can cause undesirable wafer bowing. If the bowing is significant, subsequent processing steps may be adversely affected. In some cases, wafer bowing and stress can be countered by depositing material on the backside of the wafer. However, to perform deposition on the backside of the wafer, the wafer must be flipped and loaded backside up. Flipping the wafer introduces further issues such as additional handling, potential exposure to particles, and / or reduced processing yield.

[0018] The disclosed embodiments provide implementations of a multi-station processing tool with station-varying support features (sometimes called lifting features) for backside processing such as deposition and etching. During backside deposition, etching, and / or other processing in a single station, the lifting features can block deposition, etching, and / or other processing on the wafer or other substrate being processed at the contact point of the lifting features. In some current designs, a carrier ring has the support features that hold the wafer during deposition. As the carrier ring moves from station to station in the multi-station reactor, the support features do not move further relative to the wafer. The carrier ring carries the wafer from station to station. In such designs, it is not possible to perform deposition, etching, and / or other processing on every location of the wafer.

[0019] In one embodiment, a first station can have a first set of support features that contact a wafer or other substrate being processed at a first set of locations, and a second station can have a second set of support features that contact a wafer or other substrate being processed at a second set of locations that are different from the first set of locations. As a result, areas that are blocked by the first set of support features during deposition, etching, and / or other processing at the first station can be exposed during deposition, etching, and / or other processing at the second station. This allows for control of the deposition, etching, and / or other processing profile in the azimuthal direction, allowing deposition, etching, and / or other processing of films on all portions of the backside without full thickness voids or other azimuthal non-uniformities. During etching as an example, this allows for etching all portions of the backside, with no portions being completely unetched. In some embodiments, the support features are not part of the carrier ring. Rather, the support features are part of the stations, and each station of the multi-station reactor has its own support features.

[0020] Multi-level semiconductor process flows used to fabricate advanced memory and logic chips result in significant substrate curvature in both compressive and tensile directions. This moderate to severe substrate curvature can impair processing conditions for various manufacturing processes, cause process control issues, lithography chucking, and overlay issues, and potentially increase yield loss. In one embodiment, one method to control the curvature is to deposit a sacrificial film or films on the opposite side (i.e., backside) of the substrate to compensate for the opposite curvature and flatten the substrate. A conventional dual-electrode radio frequency (RF) plasma-enhanced chemical vapor deposition (PECVD) system has one gas-flowing electrode, which can be RF or grounded. Typically, the gas-flowing electrode (also called the showerhead 104) is on the top side of the PECVD reactor and flows reactants over the front side of the wafer to cause deposition only on the front side of the wafer.

[0021] According to one embodiment, a RF PECVD system with dual gas flow electrodes is disclosed. Either one of the electrodes can be an RF electrode that provides an AC electric field that allows plasma enhancement for CVD film deposition. This dual gas flow electrode PECVD system is capable of selectively depositing films on both sides or only one side of a wafer. In one example, a gas flow pedestal (referred to herein as a "shower pedestal" or "show-ped") can hold the wafer for transport in or out of the chamber between adjacent stations via a standard transport mechanism based on the equipment setup, but can flow gases from the backside of the wafer. In some other embodiments, a system configured for backside deposition, etching, or other operations may not include a shower pedestal and may utilize other structures to flow gases to the backside of the wafer.

[0022] In one embodiment, the backside gas flow can enable PECVD deposition on the backside of the wafer, and the frontside gas flow can enable deposition on the frontside of the wafer. The system can be set to selectively enable the side of deposition by turning on and off the reactants that cause film deposition and replacing them with non-reactive gases (e.g., inert gases). Another aspect of this system is the ability to control the distance from the reactant flow gas to the side of the substrate. This control allows for the achievement of the deposition profile and film properties required for applications such as backside compensation.

[0023] In another embodiment, the show pad and showerhead include configurations that provide showerhead-like features that allow for proper reactant mixing and provide proper flow dynamics for the PECVD deposition process on the backside or frontside of the wafer. In addition, some embodiments allow for a controllable gap that can suppress or enable plasma on the desired (one or both) side of the wafer for deposition. The controlled gap can include, for example, the gap spacing between the top side of the wafer and the top surface of the showerhead 104 (as shown in FIG. 1 ) and the gap spacing between the backside of the wafer and the top surface of the show pad 106 (as shown in FIG. 1 ). For example, the gap between the top side of the wafer and the top surface of the showerhead is minimized while the backside of the wafer is being deposited.

[0024] The show ped 106 is further configured to include a showerhead hole pattern and an internal plenum for uniform distribution of gases. The showerhead hole pattern and internal plenum providing uniform distribution of gases allows the process gases to be delivered towards the bottom of the wafer with a properly uniform distribution. The embodiment also allows the gas flow pedestal (i.e., the show ped) to have an active heater to bring the process gases to the proper temperature. The combination of the show ped 106 and the showerhead 104 allows the simultaneous functioning of both important attributes. The show ped 106, in one embodiment, can still heat the wafer and provide a wafer transfer feature within the reactor chamber or outside the reactor, while the showerhead 104 components allow the flow of process gases. Thus, the gas flow pedestal (i.e., the show ped) disclosed herein allows the implementation of conventional PECVD processes that selectively deposit on either side of the wafer. These configurations are also configured to selectively provide RF power to the top or bottom electrodes to dynamically enable / disable the plasma on the side of the wafer that requires deposition.

[0025] Broadly speaking, SHOW-PED offers several advantages for addressing the stress and warpage issues by depositing a film on the backside of the wafer. The backside film counters the stress from the frontside deposition, resulting in a neutral stress (or substantially neutral stress, e.g., less than about + / - 150 MPa) wafer that does not warp (or is substantially free of warpage, e.g., less than about + / - 150 MPa). If the film deposited on the frontside is tensile, the backside film should also be tensile, balancing the overall stress. Similarly, if the frontside film is compressive, the backside film should also be compressive. The backside film can be deposited by a variety of reaction mechanisms (e.g., chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), plasma-enhanced atomic layer deposition (PEALD), low pressure chemical vapor deposition (LPCVD), etc.). In various cases, plasma-enhanced chemical vapor deposition is used due to the high deposition rates achieved with this type of reaction.

[0026] Certain deposition parameters can be adjusted to result in a backside film having a desired stress level. One of these deposition parameters is the thickness of the deposited backside film. A thicker film will induce more stress in the wafer, while a thinner film (of the same composition and deposited under the same conditions) will induce less stress in the wafer. Thus, to minimize the amount of material consumed in forming the backside layer, this layer can be deposited relatively thin under conditions that promote the formation of a highly stressed film.

[0027] In some embodiments, a multi-station processing tool can have station-variable support features for backside deposition. During backside deposition in a single station, the support features may block deposition onto the wafer or other substrate being processed at the contact points of the support features. In one implementation, a first station can have a first set of support features that contact the wafer or other substrate being processed at a first set of positions, and a second station can have a second set of support features that contact the wafer or other substrate being processed at a second set of positions that are different from the first set of positions. As a result, areas that are blocked by the first set of support features during deposition at the first station can be exposed during deposition at the second station. Thus, a backside layer can be deposited on all portions of the backside without full-layer voids. While much of this disclosure refers to the advantages of station-variable support features (also referred to as support features) for backside deposition, the station-variable support features can also be utilized to provide advantages for other types of backside processing, such as etching.

[0028] As previously mentioned, stacks of deposition materials are particularly likely to result in wafer stress and bowing. One exemplary stack that may cause these problems is a stack having alternating layers of oxide and nitride (e.g., silicon oxide / silicon nitride / silicon oxide / silicon nitride, etc.). Another exemplary stack likely to result in bowing includes alternating layers of oxide and polysilicon (e.g., silicon oxide / polysilicon / silicon oxide / polysilicon, etc.). Other examples of stack materials that may be problematic include, but are not limited to, tungsten and titanium nitride. The materials in the stack may be deposited by chemical vapor deposition techniques such as plasma-enhanced chemical vapor deposition (PECVD), low pressure chemical vapor deposition (LPCVD), metal organic chemical vapor deposition (MOCVD), atomic layer deposition (ALD), plasma-enhanced atomic layer deposition (PEALD), or by direct metal deposition (DMD), etc. These examples are not intended to be limiting. Certain disclosed embodiments may be useful whenever wafer stress and / or bowing is induced by materials present on the front side of the wafer.

[0029] The front side stack may be deposited in any number of layers and thickness. In a typical example, the stack includes about 32-72 layers and has a total thickness of about 2-4 μm. The stress induced in the wafer by the stack may be about -500 MPa to about +500 MPa, resulting in a warpage that is often about 200-400 μm (for a 300 mm wafer), and sometimes even larger.

[0030] The material deposited on the backside of the wafer can be a dielectric material in various embodiments. In some cases, oxides and / or nitrides (e.g., silicon oxide / silicon nitride) are used. Examples of silicon-containing reactants that can be used include, but are not limited to, silanes, halosilanes, and aminosilanes. Silanes contain hydrogen and / or carbon groups, but do not contain halogens. An example of a silane is silane (SiH 4 ), disilane (Si 2 H 6), and organosilanes such as methylsilane, ethylsilane, isopropylsilane, t-butylsilane, dimethylsilane, diethylsilane, di-t-butylsilane, allylsilane, sec-butylsilane, thexylsilane, isoamylsilane, t-butyldisilane, di-t-butyldisilane, and the like. Halosilanes contain at least one halogen group and may or may not contain hydrogen and / or carbon groups. Examples of halosilanes are iodosilane, bromosilane, chlorosilane, and fluorosilane. Halosilanes, particularly fluorosilanes, can form reactive halide species capable of etching silicon materials, although in certain embodiments described herein, the silicon-containing reactant is not present when the plasma strikes. A specific chlorosilane is tetrachlorosilane (SiCl 4 ), trichlorosilane (HSiCl 3 ), dichlorosilane (H 2 SiCl 2 ), monochlorosilane (ClSiH 3 ), chloroallylsilane, chloromethylsilane, dichloromethylsilane, chlorodimethylsilane, chloroethylsilane, t-butylchlorosilane, di-t-butylchlorosilane, chloroisopropylsilane, chloro-sec-butylsilane, t-butyldimethylchlorosilane, thexyldimethylchlorosilane, and the like. Aminosilanes contain at least one nitrogen atom bonded to a silicon atom, but can also contain hydrogen, oxygen, halogens, and carbon. Examples of aminosilanes are mono-, di-, tri-, and tetraaminosilanes (H, respectively). 3 Si(NH 2 ) 4 , H 2 Si(NH 2 ) 2 , HSi(NH 2 ) 3 , and Si(NH 2 ) 4 ), and substituted mono-, di-, tri-, and tetraaminosilanes, such as t-butylaminosilane, methylaminosilane, tert-butylsilane amine, bis(tert-butylamino)silane (SiH 2 (NHC(CH3 ) 3 ) 2 (BTBAS), tert-butylsilylcarbamate, SiH(CH 3 )-(N(CH 3 ) 2 ) 2 , SiHCl-(N(CH 3 ) 2 ) 2 , (Si(CH 3 ) 2 N.H. 3 etc. A further example of an aminosilane is trisilylamine (N(SiH 3 Other potential silicon-containing reactants include tetraethylorthosilicate (TEOS) and cyclic and acyclic TEOS variants such as tetramethoxysilane (TMOS), fluorotriethoxysilane (FTES), trimethylsilane (TMS), octamethyltetracyclosiloxane (OMCTS), tetramethylcyclotetrasiloxane (TMCTSO), dimethyldimethoxysilane (DMDS), hexamethyldisilazane (HMDS), hexamethyldisiloxane (HMDSO), hexamethylcyclotrisiloxane (HMCTSO), dimethyldiethoxysilane (DMDEOS), methyltrimethoxysilane (MTMOS), tetramethyldisiloxane (TMDSO), divinyltetramethyldisiloxane (VSI 2 ), methyltriethoxysilane (MTEOS), dimethyltetramethoxydisiloxane (DMTMODSO), ethyltriethoxysilane (ETEOS), ethyltrimethoxysilane (ETMOS), hexamethoxydisilane (HMODS), bis(triethoxysilyl)ethane (BTEOSE), bis(trimethoxysilyl)ethane (BTMOSE), dimethylethoxysilane (DMEOS), tetraethoxydimethyldisiloxane (TEODMDSO), tetrakis(trimethylsiloxy)silane (TTMSOS), tetramethyldiethoxydisiloxane (TMDEODSO), triethoxysilane (TIEOS), trimethoxysilane (TIMEOS), or tetrapropoxysilane (TPOS).

[0031] Exemplary nitrogen-containing reactants include, but are not limited to, ammonia, hydrazine, amines (e.g., amines having carbon), such as methylamine, dimethylamine, ethylamine, isopropylamine, t-butylamine, di-t-butylamine, cyclopropylamine, sec-butylamine, cyclobutylamine, isoamylamine, 2-methylbutan-2-amine, trimethylamine, diisopropylamine, diethylisopropylamine, di-t-butylhydrazine, and aromatic-containing amines, such as aniline, pyridine, and benzylamine. The amines can be primary, secondary, tertiary, or quaternary (e.g., tetraalkylammonium compounds). The nitrogen-containing reactants can include heteroatoms other than nitrogen, for example, hydroxylamine, t-butyloxycarbonylamine, and Nt-butylhydroxylamine are nitrogen-containing reactants.

[0032] Examples of oxygen-containing co-reactants include oxygen, ozone, nitrous oxide, carbon monoxide, nitric oxide, nitrogen dioxide, sulfur oxides, sulfur dioxide, oxygen-containing hydrocarbons (CxHyOz), water, mixtures thereof, and the like.

[0033] The flow rates of these reactants are highly dependent on the type of reaction by which the backside layer is deposited. If CVD / PECVD is used to deposit the backside layer, the flow rate of the silicon-containing reactant may be about 0.5-10 mL / min (before atomization), e.g., about 0.5-5 ml / min. The flow rate of the nitrogen-containing reactant, oxygen-containing reactant, or other co-reactant may be about 3-25 standard liters per minute (SLM), e.g., about 3-10 SLM.

[0034] In certain embodiments, the backside layer can be removed after further processing.In this case, the composition of the backside layer should be selected so that it can be easily removed from the substrate at the appropriate time.In this regard, there should be high selectivity between the material of the backside layer (e.g., dielectric) and the material of the underlying substrate (e.g., silicon) in the desired removal chemistry.

[0035] The optimal thickness of the back layer depends on the amount of stress induced by deposition on the front side of the wafer, as well as the conditions under which the back layer is deposited. The back layer can be deposited to a thickness at which stress in the wafer is negligible (e.g., less than about 150 MPa). In these or other embodiments, the back layer may be deposited to a thickness at which warpage of the wafer is negligible (e.g., less than about 150 μm warpage). In some cases, this corresponds to a back layer thickness of about 0.1-2 μm, such as about 0.3-2 μm, or about 0.1-1 μm, or about 0.3-1 μm. When silicon nitride is used to form the back layer, a film having a thickness of about 0.3 μm is sufficient to mitigate warpage of about 50-200 μm. As discussed above, a higher stress back layer can be used to reduce the required thickness of the layer. This can save material and reduce costs.

[0036] It should be appreciated that the present embodiments can be implemented in numerous ways, such as a process, an apparatus, a system, a device, or a method. Some embodiments are described below.

[0037] The deposition of the film is performed in one embodiment in a plasma-enhanced chemical vapor deposition (PECVD) system. The PECVD system can take many different forms. The PECVD system includes one or more chambers or "reactors" (which may include multiple stations) that house one or more wafers and are suitable for wafer processing. Each chamber can house one or more wafers for processing. The one or more chambers maintain the wafer in one or more defined positions (with or without movement within the position, e.g., rotation, vibration, or other agitation). The wafer being deposited can be transferred from one station to another within the reactor chamber during the process. Of course, the film deposition can be performed entirely in a single station, or any portion of the film can be deposited in any number of stations.

[0038] During processing, each wafer is held in place by a pedestal, wafer chuck, and / or other wafer holding device. For certain operations, the device may include a heater, such as a heating plate, for heating the wafer.

[0039] FIG. 1 illustrates a substrate processing system 100 used to process a wafer 128. The system includes a chamber 102. A central column is configured to support a pedestal for when the top surface of the substrate 128 is being processed, e.g., when a film is being formed on the top surface. The pedestal according to the embodiments disclosed herein is referred to as a showerhead pedestal ("showped") 106. A showerhead 104 is disposed on the showped 106. In one embodiment, the showerhead 104 is electrically coupled to a power source 122 via a match network 125. The power source 122 is controlled by a control module 120, e.g., a controller. In other embodiments, power can be provided to the showped 106 instead of the showerhead 104. The control module 120 is configured to operate the substrate processing system 100 by executing process inputs and controls for a particular recipe. Depending on whether the top surface or bottom surface of the substrate 128 is receiving a deposition film, the controller module 120 sets various operational inputs for the process recipe, such as, for example, power levels, timing parameters, process gases, mechanical movement of the wafer 128, and the height at which the wafer 128 is separated from the shower ped 106. In embodiments having multiple processing chambers 102 (such as the examples of FIGS. 2 and 3), the system 100 may include a power source 122 and associated elements, such as a match network 125, each of which is coupled to the shower ped 106 and / or showerhead 104 in each of the chambers 102. In other embodiments, a single power source 122 may be coupled to the shower ped 106 and / or showerhead 104 in multiple chambers 102. One or more of the control module 120, the gas source 114, the gas manifold 112, the gas manifold 108, the gas source 110, the match network 125, the RF power source 112, the shower pad 106, the showerhead 104, and the processing chamber can form an apparatus for depositing a film on the backside of a substrate. As described in more detail below, a multi-station processing tool can include a plurality of two or more processing stations including the aforementioned apparatus for depositing a film on the backside of a substrate.Some of the aforementioned equipment may be shared by multiple processing stations in a multi-station processing tool. In addition, a single wafer may be processed by multiple stations in a multi-station processing tool. Thus, a first processing station in the multi-station processing tool may have a first equipment for depositing a hard film on the backside of a substrate, and a second processing station in the multi-station processing tool may have a second equipment for depositing a second film on the backside of a substrate.

[0040] The central column may also include lift pins controlled by a lift pin control. The lift pins are used to raise the wafer 128 from the shower ped 106 and allow the end effector to lift the wafer and lower the wafer 128 after it has been placed by the end effector. The end effector (not shown) may also place the wafer 128 on a spacer 130. As described below, the spacer 130 is sized to provide a controlled separation of the wafer 128 between the top surface (facing the wafer) of the showerhead 104 and the top surface (facing the wafer) of the shower ped 106.

[0041] The substrate processing system 100 further includes a gas manifold 108 connected to a gas source 110, e.g., a gas chemical supply and / or an inert gas from a facility. In response to a process to be performed across an upper surface of a substrate, a control module 120 controls the delivery of the gas source 110 through the gas manifold 108. The selected gas then flows into the showerhead 104 and is distributed to a spatial volume defined between a face of the showerhead 104 facing a wafer 128 when the wafer is placed on a pedestal 140.

[0042] The substrate processing system 100 further includes a gas manifold 112 connected to a gas source 114, e.g., a gas chemical supply from a facility and / or an inert gas. Depending on the process to be performed over the bottom surface of the substrate, the control module 120 controls the delivery of the gas source 114 through the gas manifold 112. The selected gas then flows into the showerhead 104 and is distributed to a spatial volume defined between the faces of the show ped 106 that face the bottom / underside of the wafer 128 when the wafer is placed on the spacer 130. The spacer 130 provides a separation that optimizes deposition on the bottom surface of the wafer 128 while reducing deposition over the top surface of the wafer. In one embodiment, while deposition is targeted to the bottom surface of the wafer 128, an inert gas is flowed over the top surface of the wafer 128 through the showerhead 104, which displaces reactant gas from the top surface and allows reactant gas provided by the show ped 106 to be directed to the bottom surface of the wafer 128. In embodiments having multiple processing chambers 102 (such as the examples of FIGS. 2 and 3), the system 100 may include multiple gas manifolds 112, each coupled to a showerhead 106 in each of the chambers 102, and / or multiple gas manifolds 108, each coupled to a showerhead 104 in each of the chambers 102.

[0043] Additionally, the gases may or may not be premixed. Appropriate valving and mass flow control mechanisms can be used to ensure that the correct gases are delivered during the deposition and plasma treatment stages of the process. The process gases exit the chamber via an outlet. A vacuum pump (e.g., a one- or two-stage mechanical dry pump and / or turbomolecular pump) draws the process gases and maintains an appropriately low pressure in the reactor by a closed-loop controlled flow restriction device such as a throttle valve or pendulum valve.

[0044] Also shown is a carrier ring 124 surrounding an outer region of the pedestal show pedestal 106. When the top surface of the wafer 128 is being processed, e.g., material is being deposited thereon, the carrier ring 124 is configured to sit on a carrier ring support area that is stepped down from the wafer support area at the center of the pedestal show pedestal 106. The carrier ring 124 includes an outer edge side of its disk structure, e.g., an outer radius, and a wafer edge side of its disk structure, e.g., an inner radius closest to where the wafer 128 sits. The wafer edge side of the carrier ring 124 includes a number of contact support structures configured to support the wafer 128. The spacer 130 can include carrier ring support features that support the carrier ring 124. The spacer 130 can include wafer support features that support the wafer 128 away from the carrier ring 124 when the carrier ring 124 is held by the spacer 130.

[0045] In some implementations, the chamber 102 may be a processing chamber in a multi-station processing tool, and the wafer support features of the spacers 130 may engage the wafer at different azimuthal locations on the wafer depending on which station the wafer is in. As an example, the spacers 130 in a first processing station may include wafer support features that support the wafer 128 by engaging with the wafer at a first set of locations (e.g., three or more locations evenly or unevenly spaced around the wafer), and the spacers 130 in a second processing station may include wafer support features that support the wafer 128 by engaging with the wafer at a second set of locations (e.g., three or more locations evenly or unevenly spaced around the wafer). The first and second sets of locations may not overlap or may only partially overlap. In this type of arrangement, backside deposition in the first station may result in voids in the backside film applied to the wafer 128 at the first set of locations due to physical blockage at the first set of locations by the wafer support features of the spacers 130. However, backside deposition in the second station can at least partially fill those voids (because the wafer support features in the second station engage the wafer 128 at a second set of positions that do not overlap or only partially overlap the first set of positions).

[0046] In some other embodiments, the wafer 128 may be rotated as it moves from one station to the next, such that the wafer 128 engages the spacers 130 or other wafer support features at different azimuthal positions on the wafer as it sits at each of the stations. Rotation of the wafer between stations may be sufficient to ensure that the backside film is deposited in a desired manner (e.g., the backside film is free of full-thickness voids). In such embodiments, the spacers 130 or other wafer support features may be in the same azimuthal positions across multiple stations.

[0047] FIG. 2 shows a top view of a multi-station processing tool with four processing stations. The embodiment of FIG. 1 shows a chamber 102 that can be implemented in the chamber 102 of FIG. 2 and FIG. 3 having four chamber stations. FIG. 2 and FIG. 3 provide a top view of the chamber portion (e.g., with the upper chamber portion removed for illustration purposes), where the four stations are accessed by spider forks 132. Each spider fork 132, or fork, includes a first and a second arm, each of which is positioned around a portion of each side of the show ped 106. In this view, the spider forks 132 are illustrated with dashed lines to convey that they are under the carrier ring 124. The spider forks 132 are configured to use the engagement and rotation mechanism 220 to simultaneously raise and support the carrier ring 124 from the stations (i.e., from the underside of the carrier ring 124) and then rotate at least one or more stations before lowering the carrier ring 124 (at least one of which supports the wafers 128) to a next location so that further plasma processing, treatment, and / or film deposition can be performed on the respective wafers 128. As noted above, in one embodiment, the spider forks 132 can be used to lower the wafer 128 onto (and raise the wafer 128 from) a wafer support feature, such as a spacer 130. The spacer 130 can hold the wafer 128 at a height that allows deposition on the backside of the wafer 128 while substantially preventing deposition on the topside of the wafer 128, for example, as shown in FIG. 1.

[0048] 3 shows a schematic diagram of one embodiment of a multi-station processing tool having an inbound load lock 148 and an outbound load lock 140. A robot 142 is configured to move a substrate 128 from a cassette loaded via a pod 150 at atmospheric pressure to the inbound load lock 148 via an atmospheric pressure port 144. The inbound load lock 148 is coupled to a vacuum source (not shown) so that the inbound load lock 148 can be pumped down when the atmospheric pressure port 144 is closed. The inbound load lock 148 also includes a chamber transport port 146 that interfaces with the processing chamber 102. Thus, when the chamber transport 146 is opened, another robot (not shown) can move the substrate from the inbound load lock 148 to the show ped 106 of the first process station for processing.

[0049] The illustrated processing chamber 102 includes four process stations, numbered 1 through 4 in the embodiment shown in FIG. 3. In some embodiments, the processing chamber 102 may be configured to maintain a low pressure environment such that the substrate may be transferred between the process stations using a carrier ring 124 without vacuum breaking and / or air exposure. Each process station illustrated in FIG. 3 is a show ped 106 configured to deliver process gases when backside deposition is performed. If a spacer with wafer support features is used to hold the wafer away from the show ped 106 during backside deposition, the showerhead 104 may be configured to deliver an inert gas over the top surface of the substrate to prevent or reduce deposition over the top surface of the wafer 106.

[0050] 3 also illustrates spider forks 132 for transferring wafers within the processing chamber 102. As described in more detail below, the spider forks 132 can also rotate, allowing for transfer of the wafer from one station to another. Transfer is accomplished by allowing the spider forks 132 to lift the carrier ring 124 from the outer underside, thereby lifting the wafer, and then rotating both the wafer and carrier 124 to the next station. In one configuration, the spider forks 132 are made from a ceramic material to withstand the high levels of heat during processing.

[0051] In other embodiments, instead of using spider forks 132 to lift and transfer wafers, paddle-type structures can also function to lift and transfer wafers. Paddles can be positioned between stations similar to how spider forks 132 are seated and can function in the same manner. Thus, for ease of understanding, references to spider forks 132 should be understood to also apply to paddle configurations that can provide controlled lift (e.g., during backside wafer deposition) and transfer between stations. In some cases, structures (such as spider forks 132) configured to lift, support, and / or transfer wafers may be referred to as "indexers" or "rotary indexers." These structures may be part of a rotating carousel for moving wafers between stations. Thus, for ease of understanding, references to spider forks 132 should also be understood to refer to "indexers" or "rotary indexers," even if such structures differ from "spider forks" (e.g., have different structural arrangements, utilize different techniques to support and / or move wafers, etc.).

[0052] Broadly, embodiments disclosed herein relate to a system for depositing PECVD films on selective sides (front and / or backside) of a wafer with dynamic control. One embodiment includes dual gas flow electrodes to define a capacitively coupled PECVD system. The system includes a gas flow showerhead 104 and a show pedestal 106. In one embodiment, the gas flow pedestal (i.e., show ped) is a combination of a showerhead and a pedestal that allows deposition on the backside of the wafer. The electrode geometry combines features of the showerhead, such as gas mixing plenums, holes, hole patterns, gas jet prevention baffles, and features of the pedestal, such as embedded control heaters, wafer lift mechanisms (also referred to as wafer support features and wafer support structures), ability to hold plasma suppression rings, and mobility. This allows for wafer transfer and gas processing with or without RF power from the pedestal.

[0053] In one embodiment, the system has wafer support features including station variable support features. As an example, the system can have a spacer with station variable support features, such as spacer 130 of FIG. 1. In one embodiment, the wafer support features of the first process station engage the underside of the wafer, also referred to as the backside, at a first plurality of locations (e.g., three or more) along the periphery of the wafer. As a result, the wafer support features of the first process station can physically block the underside of the wafer, thus preventing backside deposition at the first plurality of locations. If backside deposition at this first station was the only backside deposition performed, the wafer would have full thickness voids in the backside film at the first plurality of locations (e.g., where the wafer support features engage and hold the wafer). Thus, in at least some embodiments, the wafer support features of the second process station are configured to engage the underside of the wafer at a second plurality of locations along the periphery of the wafer. The second plurality of locations do not overlap, or only partially overlap, the first plurality of locations. Thus, when backside deposition is performed in the second process station, the portions having full-thickness voids (e.g., areas blocked by wafer support features in the first process station) can be at least partially filled with the deposited backside layer, resulting in a multi-station processing system capable of depositing a full-thickness void-free backside film.

[0054] As desired, a multi-station processing system can have any number of processing stations (e.g., two, three, four, five, or more). In such embodiments, each processing station can have wafer support features that engage the wafer at a set of locations on the underside of the wafer that are unique to that particular processing station. Alternatively, two or more processing stations may have wafer support features that engage the wafer at a common set of locations, while one or more other processing stations have wafer support features that engage the wafer at a different set of locations. In general, increasing the number of processing stations with different engagement locations can help reduce variations in backside deposition.

[0055] In one embodiment, the system has a wafer lift mechanism that allows for precise control of the parallelism of the substrate relative to the electrodes. In one embodiment, this is achieved by setting the lift mechanism parallel to the two electrodes and controlling the manufacturing tolerances, e.g., spindle or lift pin mechanisms. Another embodiment is defined by raising the wafer lift part, but this option does not allow for dynamic control of the side receiving the deposition.

[0056] In one configuration, the lift mechanism dynamically controls the distance during the process (pre-plasma, during plasma, post-plasma) allowing control of the deposition side, deposition profile, and deposited film properties. The system further allows selective enabling / disabling of the side through which reactants flow. One side can flow reactants while the other side can flow inert gas to inhibit deposition and plasma.

[0057] In one embodiment, the gap between the sides of the wafer that do not require plasma or film deposition can be tightly controlled to inhibit the plasma (e.g., to reduce or eliminate plasma damage). In one example, the system tolerates a minimum gap of about 2 mm to about 0.5 mm, and in another embodiment, about 1 mm to about 0.05 mm (limited by wafer warpage), and such gap can be controlled. In one embodiment, the gap depends on the process conditions.

[0058] In one embodiment, the gas flow pedestal (i.e., the SHOW PED) allows for, but is not limited to, the following: (a) thermal stabilization of the wafer to a processing temperature prior to processing; (b) selective design of hole patterns on the SHOW PED to selectively deposit films on different areas of the backside of the wafer; (c) the ability to install interchangeable rings to achieve proper plasma confinement, hole patterns, and edge impedances, which may help to achieve a desired radial distribution of film properties; (d) stable wafer transfer mechanisms within the chamber, such as lift pins, RF coupling features, minimum contact arrays, and mechanisms for transferring the wafer externally to another chamber or cassette; (e) implementation of gas mixing features, such as, for example, internal plenums, baffles, and manifold line openings; and (f) adding compartments to the gas flow pedestal (i.e., the SHOW PED) to enable selective gas flow to different areas of the backside of the wafer and controlling the flow rate via flow controllers and / or multiple plenums.

[0059] In another embodiment, dynamic gap control using a wafer lift mechanism allows: (a) controlling the distance from the deposition or reactant flow electrode to the side or middle of the wafer requiring deposition, thereby allowing deposition on both sides, and (b) a lift mechanism that dynamically controls the distance during the process (pre-plasma, during plasma, post-plasma) to control the deposition side, deposition profile, and deposited film properties. In another embodiment, for deposition modes used to perform deposition on the backside of the wafer, film edge exclusion control is highly desirable to avoid lithography related overlay issues. The lift mechanism used in this system is via a carrier ring 124 that has design features that obscure the deposition on the edge. This specifies edge exclusion control via the design and shape of the carrier ring.

[0060] 4A, 4B, and 4C show bottom perspective, bottom, and side views, respectively, of the wafer carrier ring 400 and station variable support features 402a and 402b. As shown in FIG. 4A, a first processing station can have an element 401a with a first support feature 402a. FIG. 4A also shows how a second processing station can have an element 401b with a second support feature 402b. Elements 401a and 402b can be implementations of the spacer 130 of FIG. 1. Elements 401a and 401b and their associated support features 402a and 402b can be part of different processing stations in a multi-station processing tool, such as the tool of FIGS. 2 and 3 (e.g., feature 402a can be present in a first station and feature 402b can be present in a second station). In some embodiments, each processing station can have three or more support features to provide stability. Additionally, any number of the support features (all or just one, two, three, four, etc.) may be station-variable (e.g., engage the underside of the wafer in different locations depending on which station the wafer is in).

[0061] 4A, 4B, and 4C also show that in some embodiments, the wafer carrier ring 400 includes multiple wafer-retaining features 406 that support a wafer or other substrate. When the wafer carrier ring 400 is lifted (e.g., for movement between stations or processing operations), the wafer-retaining features 406 can engage the underside of the wafer. The wafer-retaining features 406 can be located along the inner periphery of the wafer carrier ring 400 in sufficient number and at suitable intervals to stably hold the wafer. In particular, there may be at least three wafer-retaining features 406 spaced apart sufficiently to maintain wafer stability. In other embodiments, the inner periphery of the top side of the wafer carrier ring 400 can function as a wafer-retaining feature (features 406 may be optionally omitted).

[0062] As part of the backside deposition, the wafer carrier ring 400 can transport the wafer to a first processing station in a multi-station processing system. The wafer carrier ring 400 may be carried in the system by spider forks 132, paddles, etc. The wafer carrier ring 400 can then be lowered (e.g., by lowering the spider forks) in the first station until the wafer rests on a first set of wafer support features including feature 402a. A backside deposition process can then be performed in the first processing station. The wafer carrier ring 400 and wafer can then be lifted and transported to a second processing station and lowered in the second station until the wafer rests on a second set of wafer support features including feature 402b. In such an embodiment, the carrier ring 400 moves from station to station with the wafer, and certain portions of the station-specific support features, such as support features 402a and 402b, leave the carrier ring and contact the wafer.

[0063] As shown in FIGS. 4A, 4B, and 4C, a support feature, such as feature 402a, of a first processing station can be configured to hold a wafer in a first set of positions (which may be immediately to the left of wafer-retaining feature 406 of wafer carrier ring 400, such as feature 402a). In contrast, a support feature, such as feature 402b, of a second processing station can be configured to hold a wafer in a second set of positions (which may be immediately to the right of wafer-retaining feature 406, such as feature 402b). With this arrangement, backside deposition in the first processing station can be blocked at the first set of positions and backside deposition in the second processing station can be blocked at the second set of positions. However, because the first and second sets of positions do not overlap, backside deposition in the second processing station can at least partially fill voids left by blockage of support features, such as feature 402a. Similarly, if backside deposition is performed at a first station after backside deposition at a second station, the backside deposition in the first station can at least partially fill voids left by blockage of support features, such as feature 402b. These types of arrangements can result in the formation of a full thickness void-free backside film. An example of these advantages is shown in FIG.

[0064] Figure 6 includes bottom images 600-604 of a wafer being processed in two stations of a multi-station processing tool. While Figure 6 is equally applicable to deposition, etch, and other fabrication processes, the following discussion is described with respect to deposition for clarity and convenience.

[0065] Image 600 shows a wafer 610 supported by three or more support features 402a in a first processing station in a multi-station processing tool. Image 600 shows the wafer 610 prior to an initial deposition of a film in the first processing station.

[0066] Image 601 shows a wafer 610 after an initial deposition of a film in a first processing station, which is indicated by a relatively lighter shading or stippling of the wafer 610 compared to image 603.

[0067] Image 602 shows wafer 610 after the wafer has been transferred to a second processing station in a multi-station processing tool. Image 602 shows wafer 610 before further deposition of a film in the second processing station. In the second processing station, wafer 610 is supported by three or more support features 402b that engage wafer 610 at a location different from support feature 402a. Thus, when wafer 610 is in the second processing station, portion 612 of wafer 610 that was previously in contact with support feature 402a is now uncovered and exposed. As can be seen in image 602, the film deposited between images 600 and 601 was not now deposited on portion 612 of wafer 610 because support feature 402 blocked deposition on portion 612.

[0068] Image 603 shows wafer 610 after further deposition of film in a second processing station. The further deposition of film is indicated by the relatively darker shading or stippling of wafer 610 compared to image 601. As shown in image 603, at least some thickness of film is deposited on portions 612, which were previously obscured by support features 402a. As indicated by the relatively light shading or stippling of portions 612 in image 603, the amount (e.g., thickness) of film deposited on portions 612 may be slightly less than the average amount (e.g., thickness) of film deposited across wafer 610.

[0069] Image 604 shows wafer 610 after further deposition of film in a second processing station, with support features 401b and other components removed for clarity. As shown in image 604, the amount of film deposited on portions 612 and 614 is a relatively smaller (e.g., thinner) amount than that deposited across the remainder of wafer 610. Thus, images 600-604 show how station variable support features can avoid full thickness voids during deposition processes. Note that similar results can be achieved in etching and other fabrication operations. As an example, when the techniques disclosed herein are applied in an etching context, station variable support features can avoid any area being completely etched. Images 600-604 also show how support features 402a of a first processing station support wafer 610 at a first set of positions, support features 402a of a second processing station support wafer 610 at a second set of positions, and how the first and second sets of positions do not overlap.

[0070] FIG. 5 illustrates a control module 500 for controlling the above-described system. In an embodiment, the control module 110 of FIG. 1 may include some of the exemplary components. For example, the control module 500 may include a processor, a memory, and one or more interfaces. The control module 500 may be used to control devices in the system based in part on sensed values. By way of example only, the control module 500 may control one or more of a valve 502, a filter heater 504, a pump 506, and other devices 508 based on sensed values ​​and other control parameters. The control module 500 receives sensed values ​​from a pressure gauge 510, a flow meter 512, a temperature sensor 514, and / or other sensors 516, by way of example only. The control module 500 may also be used to control process conditions during precursor delivery and film deposition. The control module 500 typically includes one or more memory devices and one or more processors.

[0071] The control module 500 can control the activity of the precursor delivery system and the deposition apparatus. The control module 500 executes a computer program that includes a set of instructions for controlling process timing, delivery system temperature, pressure differential across the filter, valve position, mixture of gases, chamber pressure, chamber temperature, wafer temperature, RF power levels, wafer chuck or pedestal position, and other parameters of a particular process. The control module 500 can also monitor pressure differentials and automatically switch the delivery of vapor precursors from one or more paths to one or more other paths. In some embodiments, other computer programs stored in a memory device associated with the control module 500 can be used.

[0072] Typically, there is a user interface associated with the control module 500. The user interface may include a display 518 (e.g., a display screen and / or graphical software display of equipment and / or process conditions) and user input devices 520, such as a pointing device, keyboard, touch screen, microphone, etc.

[0073] Computer programs for controlling precursor delivery, deposition, and other processes in a process sequence can be written in any conventional computer readable programming language (e.g., assembly language, C, C++, Pascal, Fortran, etc.) The compiled object code or script is executed by a processor to perform the tasks identified in the program.

[0074] The control module parameters relate to process conditions such as, for example, filter pressure differential, process gas composition and flow rate, temperature, pressure, plasma conditions such as RF power level and low frequency RF frequency, cooling gas pressure, and chamber wall temperature.

[0075] The system software can be designed or configured in many different ways. For example, various chamber component subroutines or control objects may be written to control the operation of the chamber components necessary to carry out the deposition process of the present invention. Examples of programs or sections of programs for this purpose include substrate positioning code, process gas control code, pressure control code, heater control code, and plasma control code.

[0076] The substrate positioning program may include program code for controlling chamber components used to load the substrate onto the pedestal or chuck and control spacing between the substrate and other parts of the chamber, such as gas inlets and / or targets. The process gas control program may include code for controlling gas composition and flow rates to stabilize pressure in the chamber, and optionally code for flowing gas into the chamber before deposition. The filter monitoring program may include code for comparing the measured difference to a predetermined value and / or code for switching paths. The pressure control program may include code for controlling the pressure of the chamber, for example, by adjusting a throttle valve of the exhaust system of the chamber. The heater control program may include code for controlling current to a heating unit for heating components of the precursor delivery system, the substrate, and / or other parts of the system. Alternatively, the heater control program may control the delivery of a heat transfer gas (such as helium) to the wafer chuck.

[0077] Examples of sensors that may be monitored during deposition include, but are not limited to, mass flow control modules, pressure sensors such as pressure manometers 510, and thermocouples located in the delivery system, pedestal, or chuck (e.g., temperature sensor 514). Appropriately programmed feedback and control algorithms can be used with data from these sensors to maintain desired process conditions. The foregoing describes the implementation of embodiments of the present invention in single or multi-chamber semiconductor processing tools.

[0078] In some embodiments, the plasma can be monitored in-situ by one or more plasma monitors. In one scenario, the plasma power can be monitored by one or more voltage, current sensors (e.g., VI probes). In another scenario, the plasma density and / or process gas concentration may be measured by one or more optical emission spectroscopy sensors (OES). In some embodiments, one or more plasma parameters can be programmatically adjusted based on measurements from such in-situ plasma monitors. For example, OES sensors can be used in a feedback loop to provide programmatic control of the plasma power. It will be appreciated that in some embodiments, other monitors can be used to monitor the plasma and other process characteristics. Such monitors can include, but are not limited to, infrared (IR) monitors, acoustic monitors, and pressure transducers.

[0079] Any suitable chamber may be used to perform the disclosed embodiments. Exemplary deposition equipment includes, but is not limited to, equipment from the ALTUS® product family, VECTOR® product family, and / or SPEED® product family, each available from Lam Research, Inc., Fremont, Calif., or any of a variety of other commercially available processing systems. Two or more stations may perform the same function. Similarly, two or more stations may perform different functions. Each station may be designed / configured to perform a particular function / method desired.

[0080] The system control logic may be configured in any suitable manner. In general, logic may be designed or configured in hardware and / or software. Instructions for controlling the drive circuitry may be hard-coded or provided as software. Instructions may be provided by "programming." Such programming is understood to include any form of logic, including hard-coded logic in digital signal processors, application specific integrated circuits, and other devices having specific algorithms implemented as hardware. Programming is also understood to include software or firmware instructions that may be executed on a general purpose processor. The system control software may be coded in any suitable computer readable programming language.

[0081] The computer program code for controlling the processes in the process sequence can be written in any conventional computer readable programming language (e.g., assembly language, C, C++, Pascal, Fortran, etc.). The compiled object code or script is executed by a processor to perform the tasks identified in the program. Also, as shown, the program code may be hard coded.

[0082] The controller parameters relate to process conditions such as, for example, process gas composition and flow rates, temperature, pressure, cooling gas pressure, substrate temperature, and chamber wall temperature. These parameters are provided to the user in the form of a recipe and can be entered using a user interface. Signals for monitoring the process may be provided by analog and / or digital input connections of the system controller. Signals for controlling the process are output at analog and digital output connections of the deposition device.

[0083] The system software can be designed or configured in many different ways. For example, various chamber component subroutines or control objects may be written to control the operation of chamber components necessary to perform a deposition process (and possibly other processes) according to the disclosed embodiments. Examples of programs or sections of programs for this purpose include substrate positioning code, process gas control code, pressure control code, and heater control code.

[0084] In some implementations, the controller is part of a system, and such a system may be part of the examples described above. Such a system may include semiconductor processing equipment, including one or more processing tools, one or more chambers, one or more processing platforms, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronics for controlling system operations before, during, and after processing of a semiconductor wafer or substrate. Such electronics may be referred to as a "controller" and may control various components or subparts of one or more systems. The controller may be programmed to control any of the processes disclosed herein depending on the processing requirements and / or type of system. Such processes may include delivery of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings in some systems, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and motion settings, wafer loading and unloading from the tool, and wafer loading and unloading from other transfer tools and / or load locks connected or interlocked with the particular system.

[0085] Broadly, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. Integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors, i.e., microcontrollers, that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files) that define operational parameters for performing a particular process on or for a semiconductor wafer or for a system. The operational parameters may, in some embodiments, be part of a recipe defined by a process engineer to accomplish one or more processing steps in the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or wafer dies.

[0086] The controller, in some embodiments, may be part of, coupled to, or a combination of a computer that is integrated or coupled with the system or otherwise networked to the system. For example, the controller may be in the "cloud" or all or part of a fab host computer system. This allows for remote access of wafer processing. The computer may allow remote access to the system to monitor the current progress of a fabrication operation, review the history of past fabrication operations, review trends or performance criteria from multiple fabrication operations, modify parameters of a current process, set processing steps following a current process, or start a new process. In some examples, a remote computer (e.g., a server) may provide a process recipe to the system over a network. Such a network may include a local network or the Internet. The remote computer may include a user interface that allows entry or programming of parameters and / or settings, which are then communicated from the remote computer to the system. In some examples, the controller receives instructions in the form of data. Such data identifies parameters for each processing step performed during one or more operations. It should be understood that the parameters may be specific to the type of process being performed and the type of tool that the controller is configured to interface with or control. Thus, as discussed above, the controller may be distributed, for example, by having one or more individual controllers networked together and working together toward a common purpose (such as the processes and controls described herein). An example of a distributed controller for such purposes would include one or more integrated circuits on the chamber that communicate with one or more integrated circuits located remotely (e.g., at the platform level or as part of a remote computer) and coupled to control the process in the chamber.

[0087] Exemplary systems may include, but are not limited to, a plasma etch chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a cleaning chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a tracking chamber or module, and any other semiconductor processing system that may be associated with or used in the fabrication and / or manufacturing of semiconductor wafers.

[0088] In this application, the terms "semiconductor wafer," "wafer," "substrate," "wafer substrate," and "partially fabricated integrated circuit" are used interchangeably. Those skilled in the art will understand that the term "partially fabricated integrated circuit" can refer to a silicon wafer at any of the many stages of integrated circuit fabrication. Wafers or substrates used in the semiconductor device industry typically have a diameter of 200 mm or 300 mm, although the industry is moving toward adopting 450 mm diameter substrates. In the description herein, the terms "front side" and "back side" are used to describe different sides of a wafer substrate. It is understood that the front side is where most deposition and processing occurs and where the semiconductor devices themselves are fabricated. The back side is the opposite side of the wafer and typically receives minimal or no processing during fabrication.

[0089] The flow rates and power levels provided herein are appropriate for processing on 300 mm substrates unless otherwise specified. Those skilled in the art will understand that these flow rates and power levels may be adjusted as necessary for substrates of other sizes. The following detailed description assumes that the invention is practiced on a wafer. However, the invention is not so limited. Workpieces may be of various shapes, sizes, and materials. In addition to semiconductor wafers, other workpieces that may utilize the invention include various articles such as printed circuit boards.

[0090] The apparatus / processes described herein may be used in conjunction with lithographic patterning tools or processes, for example, for the fabrication or manufacture of semiconductor devices, displays, LEDs, solar panels, and the like. Typically, but not necessarily, such tools / processes are used or performed together in a common fabrication facility. Lithographic patterning of a film typically includes some or all of the following operations, each of which is enabled by a number of available tools: (1) applying photoresist to a workpiece (i.e., substrate) using a spin-on or spray-on tool; (2) curing the photoresist using a hotplate or furnace or UV curing tool; (3) exposing the photoresist to visible or UV or X-ray light using a tool such as a wafer stepper; (4) developing the resist to selectively remove the resist, thereby patterning the resist, using a tool such as a wet bench; (5) transferring the resist pattern to an underlying film or workpiece by using a dry etching tool or a plasma-assisted etching tool; and (6) removing the resist using a tool such as an RF or microwave plasma resist stripper.

[0091] conclusion Although the foregoing embodiments have been described in some detail for clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. It should be noted that there are many alternative ways of implementing the processes, systems, and apparatus of the present embodiments. Thus, the present embodiments should be considered as illustrative rather than restrictive, and the embodiments should not be limited to the details set forth herein.

Claims

1. 1. A multi-station plasma processing system, comprising: a first processing station comprising a first set of support features configured to support the substrate at a first set of locations on a backside of the substrate when the substrate is processed in the first processing station; a second processing station comprising a second set of support features configured to hold the substrate at a second set of locations on the backside of the substrate when the substrate is processed in the second processing station; Equipped with the first set of locations does not overlap the second set of locations; Multi-station plasma processing system.

2. 10. The multi-station plasma processing system of claim 1, The first processing station further comprises a first shower pedestal, and the second processing station further comprises a second shower pedestal.

3. 3. The multi-station plasma processing system of claim 2, further comprising: a first set of support features comprising a first spacer configured to support the substrate in a first spaced relationship from the first shower pedestal, and a second set of support features comprising a second spacer configured to support the substrate in a second spaced relationship from the second shower pedestal.

4. 3. The multi-station plasma processing system of claim 2, further comprising: a first processing station coupled to the first shower pedestal for providing a first gas from a first gas source when the substrate is processed at the first processing station, and a second processing station coupled to the second shower pedestal for providing a second gas from a second gas source when the substrate is processed at the second processing station.

5. 3. The multi-station plasma processing system of claim 2, further comprising: The multi-station plasma processing system further comprises at least one radio frequency (RF) power source configured to provide power to the first shower pedestal while the substrate is supported by the first set of support features and generate a plasma for depositing a first film on the back surface of the substrate, the at least one RF power source configured to provide power to the second shower pedestal while the substrate is supported by the second set of support features and generate an additional plasma for depositing a second film on the back surface of the substrate.

6. 6. The multi-station plasma processing system of claim 5, further comprising: A multi-station plasma processing system, wherein the first set of locations do not overlap with the second set of locations, thereby depositing at least one of the first and second films over the entire back side of the substrate.

7. 7. A multi-station plasma processing system according to claim 1, further comprising: A multi-station plasma processing system, wherein the first set of support features and the second set of support features each comprise at least three support features spaced sufficiently apart to stably support the substrate.

8. 7. A multi-station plasma processing system according to claim 1, further comprising: at least one rotary indexer configured to transfer the substrate from the first processing station to the second processing station; The multi-station plasma processing system further comprises:

9. 7. A multi-station plasma processing system according to claim 1, further comprising: at least one rotary indexer configured to lift a carrier ring such that the carrier ring engages and lifts the substrate from the first set of support features, transfer the carrier ring and the substrate from the first processing station to the second processing station, and lower the carrier ring so that the substrate is placed onto the second set of support features and the carrier ring disengages from the substrate; The multi-station plasma processing system further comprises:

10. 1. A multi-station plasma processing system for processing a substrate having a nominal diameter of D, comprising: a first processing station having a first set of support features; a second processing station having a second set of support features; an indexer configured to rotate about a central axis thereby transferring the substrate from the first processing station to the second processing station; Equipped with the first set of support features having a first diameter of D and a first set of contact surfaces positioned within a first circular area centered about a first center point of the first processing station; the second set of support features having a second diameter of D and a second set of contact surfaces positioned within a second circular area centered about a second center point of the second processing station; the rotational transformation of the first center point and the first set of contact surfaces about the central axis such that the rotationally transformed first center point is aligned with the second center point results in no overlap between the second set of contact surfaces and the rotationally transformed first set of contact surfaces when viewed along the central axis. Multi-station plasma processing system.

11. 11. The multi-station plasma processing system of claim 10, further comprising: The first processing station further comprises a first shower pedestal, and the second processing station further comprises a second shower pedestal.

12. 12. The multi-station plasma processing system of claim 11, further comprising: a first set of support features comprising a first spacer configured to support the substrate in a first spaced relationship from the first shower pedestal, and a second set of support features comprising a second spacer configured to support the substrate in a second spaced relationship from the second shower pedestal.

13. 13. A multi-station plasma processing system according to any one of claims 10 to 12, comprising: A multi-station plasma processing system, wherein the first set of support features and the second set of support features each comprise at least three support features spaced sufficiently apart to stably support the substrate.

14. 13. A multi-station plasma processing system according to any one of claims 10 to 12, comprising: A multi-station plasma processing system, wherein the first processing station comprises a first device for depositing a first film on a back surface of the substrate, and the second processing station comprises a second device for depositing a second film on the back surface of the substrate.

15. 15. The multi-station plasma processing system of claim 14, further comprising: A multi-station plasma processing system, wherein the first set of contact surfaces are configured to contact the back surface of the substrate at a first set of back surface locations, the second set of contact surfaces are configured to contact the back surface of the substrate at a second set of back surface locations, the first set of support features block deposition of the first film at the first set of back surface locations, and the second set of support features enable deposition of the second film at the first set of back surface locations.

16. 16. The multi-station plasma processing system of claim 15, further comprising: A multi-station plasma processing system, wherein the first set of support features enables deposition of the first film at the second set of backside locations and the second set of support features blocks deposition of the second film at the second set of backside locations.

17. 1. A method for processing a backside of a substrate in a multi-station plasma processing system, the multi-station plasma processing system including a first station having a first set of support features, the multi-station plasma processing system including a second station having a second set of support features, the method comprising: moving a substrate over the first set of support features; processing the back side of the substrate while the substrate is on the first set of support features, the first set of support features blocking processing of the back side of the substrate at a first set of locations on the back side of the substrate; moving the substrate over the second set of support features; processing the back side of the substrate while the substrate is on the second set of support features, wherein the second set of support features do not block processing of the back side of the substrate at the first set of locations on the back side of the substrate; A method comprising:

18. 20. The method of claim 17, The method, wherein the first set of locations does not overlap the second set of locations.

19. 19. The method of any one of claims 17 or 18, comprising: The method, wherein the second set of support features block processing of the back surface of the substrate at a second set of locations on the back surface of the substrate.

20. 20. The method of claim 19, The method, wherein the first set of support features do not block processing of the back surface of the substrate at the second set of locations on the back surface of the substrate.

21. 19. The method of any one of claims 17 or 18, comprising: The method, wherein the multi-station plasma processing system further includes an indexer, and moving the substrate onto the second set of support features includes rotating the indexer about a central axis to move the substrate from the first station to the second station.

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