Patent Description:
Reliably producing submicron and smaller features is one of the key technologies for the next generation of very large scale integration (VLSI) and ultra large scale integration (ULSI) of semiconductor devices. However, as the fringes of circuit technology are pressed, the shrinking dimensions of interconnects in VLSI and ULSI technology have placed additional demands on the processing capabilities. The multilevel interconnects that lie at the heart of VLSI and ULSI technology use precise processing of high aspect ratio features, such as vias and other interconnects. Reliable formation of these interconnects is very important to VLSI and ULSI success and to the continued effort to increase circuit density and quality of individual substrates.

As circuit densities increase, the widths of interconnects, such as vias, trenches, contacts, and other features, as well as the dielectric materials between, decrease while the thickness of the dielectric layers remain substantially constant, resulting in increased height-to-width aspect ratios of the features. Many traditional deposition processes have difficulty filling submicron structures where the aspect ratio exceeds <NUM>:<NUM>, and particularly where the aspect ratio exceeds <NUM>:<NUM>. Therefore, there is a great amount of ongoing effort being directed at the formation of substantially void-free and seam-free submicron features having high aspect ratios.

Atomic layer deposition (ALD) is a deposition technique being explored for the deposition of material layers over features having high aspect ratios. One example of an ALD process includes the sequential introduction of pulses of gases. For instance, one cycle for the sequential introduction of pulses of gases may contain a pulse of a first reactant gas, followed by a pulse of a purge gas and/or a pump evacuation, followed by a pulse of a second reactant gas, and followed by a pulse of a purge gas and/or a pump evacuation. The term "gas" as used herein is defined to include a single gas or a plurality of gases. Sequential introduction of separate pulses of the first reactant and the second reactant may result in the alternating self-limiting absorption of monolayers of the reactants on the surface of the substrate and, thus, forms a monolayer of material for each cycle. The cycle may be repeated to a desired thickness of the deposited material. A pulse of a purge gas and/or a pump evacuation between the pulses of the first reactant gas and the pulses of the second reactant gas serves to reduce the likelihood of gas phase reactions of the reactants due to excess amounts of the reactants remaining in the chamber.

In some chamber designs for ALD processing, precursors and gases are delivered using a funnel lid through which precursor is distributed through multiple injectors above a funnel shaped lid. The injectors generate a circular motion of the injected gas which distributes through the funnel profile at the center of the lid. The rotational inertia of the gas/ALD precursor molecules distributes the molecules from center to edge resulting in improved uniformity deposition. However, in some applications, the inventors have observed a donut-shaped deposition profile near the center of the substrate being processed. The donut-shaped deposition profile is believed to be caused by the funnel shape of the lid and can lead to integration issues for customers.

For example, <CIT> describes a manufacturing method of semiconductor device and substrate processing apparatus. As another example, <CIT> describes a cleaning device of CVD reaction chamber. <CIT> describes a substrate processing apparatus, method of manufacturing semiconductor device and non-transitory computer-readable recording medium. In a yet further example, <CIT> describes an apparatus and method for forming thin film using upstream and downstream exhaust mechanism. Further, <CIT> describes a semiconductor reaction chamber showerhead.

Therefore, the inventors have provided improved apparatus and methods for ALD processing of a substrate.

Methods and apparatus for processing a substrate are provided herein. The invention provides a substrate processing chamber according to claim <NUM> and a method of processing a substrate according to claim <NUM>. The substrate processing chamber includes: a chamber body; a chamber lid assembly having a housing enclosing a funnel shaped gas dispersion channel that extends along a central axis and has an upper portion and a lower portion; a gas delivery system configured to provide one two or more gases to the gas dispersion channel; a remote plasma source RPS fluidly coupled to the gas dispersion channel; and a cleaning gas source fluidly coupled to the RPS; an isolation collar coupled between the remote plasma source and the housing, wherein the isolation collar has an inner channel extending through the isolation collar to fluidly couple the remote plasma source and the gas dispersion channel, wherein an exhaust system having an exhaust conduit is coupled to the isolation collar; and a lid plate coupled to the housing and having a contoured lower surface that is downwardly sloping to extend downwardly and outwardly from a central opening coupled to the lower portion of the funnel shaped gas dispersion channel to a peripheral portion of the lid plate; and a gas distribution plate disposed below the lid plate and having a plurality of apertures disposed through the gas distribution plate, wherein the contoured lower surface of the lid plate extends to and contacts the gas distribution plate, such that the gas distribution plate extends to a surface of the gas dispersion channel such that the only pathway from the gas dispersion channel to the substrate is through the plurality of apertures of the gas distribution plate.

The method of processing a substrate in a substrate processing chamber according to claim <NUM> includes: flowing a first process gas into the gas dispersion channel of the channel lid assembly and a reaction zone of the substrate processing chamber; flowing the first process gas through th plurality of apertures in the gas distribution plate disposed in the reaction zone and onto the substrate; flowing a cleaning gas into the gas dispersion channel and the reaction zone; exhausting the cleaning gas via the exhaust system; flowing a second process gas into the gas dispersion channel and the reaction zone; flowing the second process gas through the plurality of apertures in the gas distribution plate and onto the substrate; flowing the cleaning gas into the gas dispersion channel and the reaction zone; and exhausting the cleaning gas via the exhaust system.

Other and further embodiments of the present disclosure are described below.

Embodiments of the present disclosure, briefly summarized above and discussed in greater detail below, can be understood by reference to the illustrative embodiments of the disclosure depicted in the appended drawings. However, that the appended drawings illustrate only typical embodiments of the disclosure and are therefore not to be considered limiting of scope, for the disclosure may admit to other equally effective embodiments.

The figures are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

Embodiments of the present disclosure provide apparatus and methods that may be used to clean substrate processing chambers, such as an atomic layer deposition (ALD) chamber, and to deposit materials during, for example, an ALD process. Embodiments include substrate processing chambers and gas delivery systems which include a remote plasma source and a gas distribution plate. Other embodiments provide methods for depositing materials using these gas delivery systems during ALD processes. Examples of suitable processing chambers for incorporation of the apparatuses described herein include high dielectric constant (i.e., high k) and metal ALD deposition chambers available from Applied Materials, Inc. , of Santa Clara, California. The following process chamber description is provided for context and exemplary purposes, and should not be interpreted or construed as limiting the scope of the disclosure.

<FIG> is a schematic view of a substrate processing chamber (process chamber <NUM>) including a gas delivery system <NUM> adapted for ALD processes. <FIG> is a cross-sectional view of the process chamber <NUM>. Process chamber <NUM> includes a chamber body <NUM> having a processing volume within the chamber body <NUM> and beneath the chamber lid assembly <NUM>. Slit valve <NUM> in the process chamber <NUM> provides access for a robot (not shown) to deliver and retrieve a substrate <NUM>, such as a <NUM> or <NUM> semiconductor wafer or a glass substrate, to and from the process chamber <NUM>. A chamber liner <NUM> is disposed along the walls of the process chamber <NUM> to protect the chamber from corrosive gases used during processing/cleaning.

A substrate support <NUM> supports the substrate <NUM> on a substrate receiving surface <NUM> in the process chamber <NUM>. The substrate support <NUM> is mounted to a lift motor <NUM> for raising and lowering the substrate support <NUM> and the substrate <NUM> disposed on the substrate support. A lift plate <NUM> (shown in <FIG>), connected to a lift motor <NUM>, is mounted in the process chamber <NUM> to raise and lower lift pins <NUM> movably disposed through the substrate support <NUM>. The lift pins <NUM> raise and lower the substrate <NUM> over the surface of the substrate support <NUM>. The substrate support <NUM> may include a vacuum chuck (not shown), an electrostatic chuck (not shown), or a clamp ring (not shown) for securing the substrate <NUM> to the substrate support <NUM> during a deposition process.

The temperature of the substrate support <NUM> may be adjusted to control the temperature of the substrate <NUM>. For example, substrate support <NUM> may be heated using an embedded heating element, such as a resistive heater (not shown), or may be heated using radiant heat, such as heating lamps (not shown) disposed above the substrate support <NUM>. A purge ring <NUM> may be disposed on the substrate support <NUM> to define a purge channel <NUM> which provides a purge gas to a peripheral portion of the substrate <NUM> to prevent deposition on the peripheral portion of the substrate <NUM>.

Gas delivery system <NUM> is disposed at an upper portion of the chamber body <NUM> to provide a gas, such as a process gas and/or a purge gas, to process chamber <NUM>. A vacuum system (not shown) is in communication with a pumping channel <NUM> to evacuate any desired gases from the process chamber <NUM> and to help maintain a desired pressure or pressure range inside the process chamber <NUM>.

The chamber lid assembly <NUM> includes a gas dispersion channel <NUM> extending through a central portion of the chamber lid assembly <NUM>. As shown in <FIG> and <FIG>, the gas dispersion channel <NUM> extends perpendicularly toward the substrate receiving surface <NUM> and also extends along a central axis <NUM> of the gas dispersion channel <NUM>, through lid plate <NUM>, and to lower surface <NUM>. In some embodiments, an upper portion of the gas dispersion channel <NUM> is substantially cylindrical along central axis <NUM> and a lower portion of the gas dispersion channel <NUM> tapers away from central axis <NUM>. The lower surface <NUM> is sized and shaped to substantially cover the substrate <NUM> disposed on the substrate receiving surface <NUM> of the substrate support <NUM>. The lower surface <NUM> tapers from an outer edge of the lid plate <NUM> towards the gas dispersion channel <NUM>. The gas delivery system <NUM> may provide two or more gasses to the gas dispersion channel <NUM> to process the substrate <NUM>. In some embodiments, the gas delivery system <NUM> may be coupled to the gas dispersion channel <NUM> via one gas inlet. In some embodiments, such as that shown in <FIG>, the gas delivery system may be coupled to the gas dispersion channel <NUM> via a plurality of inlets.

As illustrated in <FIG>, circular gas flow <NUM>, which illustrates the flow of process gases through the gas dispersion channel <NUM>, may contain various types of flow patterns. In some embodiments, processing gases may be forced to make revolutions around central axis <NUM> of gas dispersion channel <NUM> while passing through the dispersion channel. In such embodiments, the circular gas flow <NUM> may contain various types of circular flow patterns, such as a vortex pattern, a helix pattern, a spiral pattern, or derivatives thereof.

Although providing a circular gas flow <NUM> is beneficial for many applications, the inventors have discovered that in some applications, the circular gas flow can lead to non-uniform processing results. The inventors have observed the gas flow may lead to a donut-shaped deposition profile near a center of the substrate <NUM> being processed. The donut-shaped profile may be caused by the funnel shape of gas dispersion channel <NUM>. Therefore, the process chamber <NUM> further includes a gas distribution plate <NUM> having a plurality of apertures <NUM> disposed through the gas distribution plate <NUM>. The gas distribution plate <NUM> extends to the surface of the gas dispersion channel <NUM> such that the only pathway from the gas dispersion channel <NUM> to the substrate is through the plurality of apertures <NUM> of the gas distribution plate <NUM>. The gas distribution plate <NUM> advantageously creates a choked flow of gas through the gas distribution plate <NUM> resulting in a more uniform deposition on the substrate <NUM> and, thus, substantially eliminating the donut-shaped deposition caused by the rotational flow of gas.

In some embodiments, the gas distribution plate <NUM> is formed of a non-corrosive ceramic material such as, for example, aluminum oxide or aluminum nitride. In some embodiments, each of the plurality of apertures <NUM> may have an equivalent fluid conductance. In some embodiments, a density of the plurality of apertures <NUM> (e.g., the number of apertures or the size of the openings of the apertures per unit area) may vary across the gas distribution plate <NUM> to achieve a desired deposition profile on the substrate <NUM>. For example, a higher density of apertures <NUM> may be disposed at a center of the gas distribution plate <NUM> to increase the deposition rate at the center of the substrate relative to the edge of the substrate to further improve deposition uniformity.

Although the plurality of apertures <NUM> are depicted as cylindrical through holes, the plurality of apertures <NUM> may have different profiles. <FIG> depict different non-limiting embodiments of profiles of the plurality of apertures <NUM>. In the embodiment depicted in <FIG>, the aperture <NUM> is a cylindrical through hole having curved edges <NUM> that surround the aperture. In the embodiment depicted in <FIG>, the aperture <NUM> is a through hole having an upper portion <NUM> that tapers inwardly toward a center of the aperture, a cylindrical center portion <NUM> extending perpendicularly to an upper surface <NUM> of the gas distribution plate <NUM>, and a lower portion <NUM> that tapers outwardly from the center of the aperture. In the embodiment depicted in <FIG>, the aperture <NUM> is a through hole having an upper portion <NUM> having a countersunk hole, a cylindrical center portion <NUM> extending perpendicularly to the upper surface <NUM> of the gas distribution plate <NUM>, and a lower portion <NUM> that tapers outwardly from the center of the aperture. Other profiles of the plurality of apertures <NUM> may alternatively be used to achieve optimal deposition uniformity during processing of the substrate <NUM>.

Not wishing to be bound by theory, the inventors believe that the diameter of gas dispersion channel <NUM>, which is constant from the upper portion of gas dispersion channel <NUM> to a first point along central axis <NUM> and increasing from the first point to lower portion <NUM> of gas dispersion channel <NUM>, allows less of an adiabatic expansion of a gas through gas dispersion channel <NUM> which helps to control the temperature of the process gas contained in the circular gas flow <NUM>. For example, a sudden adiabatic expansion of a gas delivered into gas dispersion channel <NUM> may result in a drop in the temperature of the gas which may cause condensation of the gas and formation of droplets. On the other hand, a gas dispersion channel <NUM> that gradually tapers is believed to provide less of an adiabatic expansion of a gas. Therefore, more heat may be transferred to or from the gas, and, thus, the temperature of the gas may be more easily controlled by controlling the temperature of chamber lid assembly <NUM>. Gas dispersion channel <NUM> may gradually taper and contain one or more tapered inner surfaces, such as a tapered straight surface, a concave surface, a convex surface, or combinations thereof or may contain sections of one or more tapered inner surfaces (i.e., a portion tapered and a portion non-tapered).

As shown in <FIG>, the upper portion of the gas dispersion channel <NUM> is defined by an insert <NUM> disposed in an inner region of a housing <NUM>. The insert <NUM> includes a cap <NUM> at an upper portion of the insert <NUM> and a central passageway that at least partially defines the gas dispersion channel <NUM>. The cap <NUM> extends over the housing <NUM> to hold the insert <NUM> in place. The insert <NUM> and cap <NUM> include a plurality of o-rings <NUM> disposed between the insert <NUM> and the housing <NUM> to ensure proper sealing. The insert <NUM> includes a plurality of circumferential apertures which, when the insert <NUM> is inserted into the housing <NUM>, form a corresponding plurality of circumferential channels <NUM>, <NUM>, <NUM>. The plurality of circumferential channels <NUM>, <NUM>, <NUM> are fluidly coupled to the gas dispersion channel <NUM> via a corresponding plurality of holes <NUM>, <NUM>, <NUM>. In the embodiment shown in <FIG>, the gas delivery system <NUM> is coupled to the gas dispersion channel <NUM> via a plurality of gas feed lines <NUM>, <NUM>, <NUM>. The gas feed lines <NUM>, <NUM>, <NUM> are fluidly coupled to the plurality of circumferential channels <NUM>, <NUM>, <NUM> to provide one or more gases to the gas dispersion channel <NUM>.

Returning to <FIG> and <FIG>, the process chamber <NUM> further includes a chamber cleaning system including a remote plasma source (RPS) <NUM>, an isolation collar <NUM> coupled to the RPS <NUM> at one end and the cap <NUM> at an opposite end, a heater plate <NUM> coupled to an upper surface of the lid plate <NUM>, and a cleaning gas (i.e., purge gas) source <NUM> fluidly coupled to the RPS <NUM>. The cleaning gas source may include any gas suitable for forming a plasma to clean the process chamber <NUM>. In some embodiments, for example, the cleaning gas may be nitrogen trifluoride (NF<NUM>). The isolation collar <NUM> includes an inner channel <NUM> that is fluidly coupled to the gas dispersion channel <NUM> through a plurality of holes <NUM> disposed in a central portion of the cap <NUM> to flow a plasma from the RPS <NUM> through the gas dispersion channel <NUM> and into the reaction zone <NUM>. The heater plate <NUM> may be formed of stainless steel and include a plurality of resistive heating elements dispersed throughout the plate.

Typically, a cleaning gas is flowed through the gas dispersion channel <NUM> and the reaction zone <NUM> after a first gas is provided to the gas dispersion channel <NUM> by the gas delivery system <NUM> to quickly purge the first gas from the gas dispersion channel <NUM> and the reaction zone <NUM>. Subsequently, a second gas is provided by the gas delivery system <NUM> to the gas dispersion channel <NUM> and the cleaning gas is again flowed through the gas dispersion channel <NUM> to the reaction zone <NUM> to quickly purge the second gas from the gas dispersion channel <NUM> and the reaction zone <NUM>. However, the addition of the gas distribution plate <NUM> chokes the flow of the cleaning gas to the pumping channel <NUM> and prolongs the cleaning process. As such, the inventors have incorporated an exhaust system <NUM> having an exhaust conduit <NUM> coupled to the isolation collar <NUM> at a first end <NUM> and to the pumping channel <NUM> at a second end <NUM>. A valve <NUM> is disposed in the exhaust conduit <NUM> to selectively fluidly couple the exhaust conduit <NUM> to the inner channel <NUM>. In some embodiments, for example, the valve <NUM> may be a plunger type valve having a plunger <NUM> that is moveable between a first position (shown in <FIG>) to fluidly couple the exhaust conduit <NUM> to the inner channel <NUM> and a second position to seal off the exhaust conduit <NUM> from the inner channel <NUM>. Each time the cleaning gas is flowed through the gas dispersion channel <NUM> and the reaction zone <NUM>, the valve <NUM> is opened and the cleaning gas is rapidly exhausted to the pumping channel <NUM>.

When a pressure inside of the process chamber <NUM> exceeds a pressure inside of the RPS <NUM>, processing gasses may flow up to and damage the RPS <NUM>. The plurality of holes <NUM> serve as a choke point to prevent a backflow of processing gases from flowing up through the inner channel <NUM> and into the RPS <NUM>. The isolation collar <NUM> may be formed of any material that is non-reactive with the cleaning gas being used. In some embodiments, the isolation collar <NUM> may be formed of aluminum when the cleaning gas is NF<NUM>. In some embodiments, the isolation collar <NUM> and the insert <NUM> may be formed of aluminum and coated with a coating to prevent corrosion of the isolation collar <NUM> and the insert <NUM> from corrosive gases when used. For example, the coating may be formed of nickel or aluminum oxide.

Referring to <FIG>, the RPS <NUM> operates at a temperature less than or equal to about <NUM>. In order advantageously insulate the RPS <NUM> from heat generated in the process chamber <NUM>, a thermal isolation ring <NUM> is disposed between the isolation collar <NUM> and the cap <NUM>. The thermal isolation ring <NUM> is formed of a metal with low thermal conductivity (e.g., lower than the thermal conductivity of the isolation collar <NUM> and the cap <NUM>). In addition, an o-ring <NUM> may also be disposed between the isolation collar <NUM> and the cap <NUM> to further reduce the contact area between the isolation collar <NUM> and the cap <NUM>. The combination of the thermal isolation ring <NUM> and the o-ring <NUM> acts as a thermal choke to ensure that the heat generated in the process chamber <NUM> does not adversely affect the RPS <NUM>.

In some embodiments, when the lid plate <NUM> is heated above <NUM> the process chamber <NUM> may include a differential pumping line <NUM> to ensure that any process gases or byproducts trapped between o-rings <NUM> are exhausted to the pumping channel <NUM>. The differential pumping line <NUM> is coupled to the lid plate <NUM> at a first end and to the housing <NUM> at a second end opposite the first end. The differential pumping line is fluidly coupled to the gas dispersion channel <NUM> and to one or more channels <NUM> formed at areas between two or more o-rings <NUM>. When the valve <NUM> is opened to exhaust the gas dispersion channel <NUM>, the differential pumping line exhausts gases trapped between o-rings <NUM>.

Returning to <FIG>, a portion of lower surface <NUM> of chamber lid assembly <NUM> is contoured or angled downwardly and outwardly from a central opening coupled to the gas dispersion channel <NUM> to a peripheral portion of chamber lid assembly <NUM> to help provide an improved velocity profile of a gas flow from gas dispersion channel <NUM> across the surface of substrate <NUM> (i.e., from the center of the substrate to the edge of the substrate). Lower surface <NUM> may contain one or more surfaces, such as a straight surface, a concave surface, a convex surface, or combinations thereof. In one embodiment, lower surface <NUM> is convexly funnel-shaped.

A lower surface <NUM> is downwardly and outwardly sloping toward an edge of the substrate receiving surface <NUM> to help reduce the variation in the velocity of the process gases traveling between lower surface <NUM> of chamber lid assembly <NUM> and substrate <NUM> while assisting to provide uniform exposure of the surface of substrate <NUM> to a reactant gas. The components and parts of chamber lid assembly <NUM> may contain materials such as stainless steel, aluminum, nickel-plated aluminum, nickel, alloys thereof, or other suitable materials. In one embodiment, lid plate <NUM> may be independently fabricated, machined, forged, or otherwise made from a metal, such as aluminum, an aluminum alloy, steel, stainless steel, alloys thereof, or combinations thereof.

In some embodiments, inner surface <NUM> of gas dispersion channel <NUM> and lower surface <NUM> of chamber lid assembly <NUM> may contain a mirror polished surface to help a flow of a gas along gas dispersion channel <NUM> and lower surface <NUM> of chamber lid assembly <NUM>.

Referring to <FIG>, in a processing operation, substrate <NUM> is delivered to process chamber <NUM> through slit valve <NUM> by a robot (not shown). Substrate <NUM> is positioned on substrate support <NUM> through cooperation of lift pins <NUM> and the robot. Substrate support <NUM> raises substrate <NUM> into close opposition to a lower surface of the gas distribution plate <NUM>. A first gas flow may be injected into gas dispersion channel <NUM> of process chamber <NUM> by the gas delivery system <NUM> together or separately (i.e., pulses) with a second gas flow. The first gas flow may contain a continuous flow of a purge gas from a purge gas source and pulses of a reactant gas from a reactant gas source or may contain pulses of a reactant gas from the reactant gas source and pulses of a purge gas from the purge gas source. The second gas flow may contain a continuous flow of a purge gas from a purge gas source and pulses of a reactant gas from a reactant gas source or may contain pulses of a reactant gas from a reactant gas source and pulses of a purge gas from a purge gas source.

The circular gas flow <NUM> travels through gas dispersion channel <NUM> and subsequently through the plurality of apertures <NUM> in the gas distribution plate <NUM>. The gas is then deposited on the surface of substrate <NUM>. Lower surface <NUM> of chamber lid assembly <NUM>, which is downwardly sloping, helps reduce the variation of the velocity of the gas flow across the surface of gas distribution plate <NUM>. Excess gas, by-products, etc. flow into the pumping channel <NUM> and are then exhausted from process chamber <NUM>. Throughout the processing operation, the heater plate <NUM> may heat the chamber lid assembly <NUM> to a predetermined temperature to heat any solid byproducts that have accumulated on walls of the process chamber <NUM> (or a processing kit disposed in the chamber). As a result, any accumulated solid byproducts are vaporized. The vaporized byproducts are evacuated by a vacuum system (not shown) and pumping channel <NUM>. In some embodiments, the predetermined temperature is greater than or equal to <NUM>.

<FIG> illustrates a method <NUM> of processing a substrate in accordance with some embodiments of the present disclosure. At <NUM>, a first process gas is flowed from the gas delivery system <NUM> into the gas dispersion channel <NUM> and the reaction zone <NUM>. At <NUM>, the first process gas is flowed through the plurality of apertures <NUM> in the gas distribution plate <NUM> and onto the substrate <NUM>. At <NUM>, a cleaning gas is flowed into the gas dispersion channel <NUM> and the reaction zone <NUM> to purge the first process gas. At <NUM>, the cleaning gas is exhausted via the exhaust system <NUM>. At <NUM> a second process gas is flowed into the gas dispersion channel <NUM> and the reaction zone <NUM>. At <NUM>, the second process gas is flowed through the plurality of apertures <NUM> in the gas distribution plate <NUM> and onto the substrate <NUM>. At <NUM>, the cleaning gas is flowed into the gas dispersion channel <NUM> and the reaction zone <NUM> to purge the second process gas. At <NUM>, the cleaning gas is exhausted via the exhaust system <NUM>.

Other embodiments of a chamber adapted for atomic layer deposition incorporate one or more of these features.

Claim 1:
A substrate processing chamber, comprising:
a chamber body (<NUM>);
a chamber lid assembly (<NUM>) having a housing (<NUM>) enclosing a funnel shaped gas dispersion channel (<NUM>) that extends along a central axis (<NUM>) and has an upper portion and a lower portion;
a gas delivery system (<NUM>) configured to provide two or more gases to the gas dispersion channel (<NUM>);
a lid plate (<NUM>) coupled to the housing (<NUM>) and having a contoured lower surface (<NUM>) that is downwardly sloping to extend downwardly and outwardly from a central opening coupled to the lower portion of the funnel shaped gas dispersion channel (<NUM>) to a peripheral portion of the lid plate (<NUM>); and
a gas distribution plate (<NUM>) disposed below the lid plate (<NUM>) and having a plurality of apertures (<NUM>) disposed through the gas distribution plate (<NUM>) wherein
the contoured lower surface (<NUM>) of the lid plate (<NUM>) extends to and contacts the gas distribution plate (<NUM>), such that the gas distribution plate (<NUM>) extends to a surface of the gas dispersion channel (<NUM>) such that the only pathway from the gas dispersion channel (<NUM>) to the substrate is through the plurality of apertures of the gas distribution plate (<NUM>); and
a remote plasma source RPS (<NUM>) fluidly coupled to the gas dispersion channel (<NUM>);
a cleaning gas source (<NUM>) fluidly coupled to the RPS (<NUM>); and
an isolation collar (<NUM>) coupled between the remote plasma source (<NUM>) and the housing (<NUM>), the isolation collar (<NUM>) has an inner channel extending through the isolation collar (<NUM>) to fluidly couple the remote plasma source (<NUM>) and the gas dispersion channel (<NUM>), wherein an exhaust system (<NUM>) having an exhaust conduit (<NUM>) is coupled to the isolation collar (<NUM>).