Patent ID: 12234549

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

DETAILED DESCRIPTION

Embodiments presented herein are directed to methods of in situ ceramic coating deposition for radio frequency active surface protection and emissivity control. A seasoning process is used to coat a seasoning layer on one or more chamber components and/or interior surfaces of a process chamber.

FIG.1is a schematic view of a processing system132suitable for performing a plasma process described herein. The processing system132may be a suitably adapted CENTURA®, Producer® SE or Producer® GT or Producer® XP processing system available from Applied Materials, Inc., of Santa Clara, California. It is contemplated that other processing systems, including those produced by other manufacturers, may benefit from embodiments described herein.

The processing system132includes a chamber body151. The chamber body151includes a chamber lid125, a sidewall101and a bottom wall122that define an interior volume126.

A substrate support pedestal150is provided in the interior volume126of the chamber body151. The pedestal150is fabricated from aluminum, ceramic, and other suitable materials. In one embodiment, the pedestal150is fabricated by a ceramic material, such as aluminum nitride, which is a material suitable for use in a high temperature environment, such as a plasma process environment, without causing thermal damage to the pedestal150. The pedestal150is capable of moving in a vertical direction inside the chamber body151using a lift mechanism (not shown).

The pedestal150may include an embedded heater element170suitable for controlling the temperature of a substrate190supported on the pedestal150. The pedestal150may be resistively heated by applying an electric current (e.g., alternating current) from a power supply106to the heater element170. The electric current supplied from the power supply106is regulated by the controller110to control the heat generated by the heater element170, thereby maintaining the substrate190and the pedestal150at a substantially constant temperature during film deposition at any suitable temperature range. The substrate190is retained on the pedestal150by clamping, vacuum, electrostatic chucking, or gravity.

The pedestal150is configured as a cathode having the electrode192embedded therein coupled to at least one RF bias power source (e.g., RF bias power sources184,186). The RF bias power sources184,186are coupled between the electrode192disposed in the pedestal150and another electrode, such as an electrode141of the gas distribution plate142or an electrode121chamber lid125of the processing system132. The RF bias power source184,186excites and sustains a plasma discharge formed from the gases disposed in the processing region of the processing system132.

The RF bias power sources184,186are coupled to the electrode192disposed in the pedestal150through a matching circuit104. The signal generated by the RF bias power source184,186is delivered through matching circuit104to the pedestal150through a single feed to ionize the gas mixture provided in the plasma processing system132, thereby providing ion energy necessary for performing a deposition or other plasma enhanced process. The RF bias power sources184,186are generally capable of producing an RF signal having a frequency of from about 50 KHz to about 200 MHz and a power between about 0 Watts and about 5000 Watts.

A vacuum pump102is coupled to a port formed in the bottom122of the chamber body151. The vacuum pump102is used to maintain a desired gas pressure in the chamber body151. The vacuum pump102also evacuates post-processing gases and by-products of the process from the chamber body151.

The processing system132includes one or more gas delivery passages144coupled through the chamber lid125of the processing system132. The gas delivery passage144is coupled to the gas source193to provide a gas mixture into the interior volume126. In one embodiment, which can be combined with any embodiment described herein, the gas mixture supplied through the gas delivery passage144is further delivered through a gas distribution plate142disposed below the gas delivery passage144. The gas distribution plate142has a plurality of apertures143and is coupled to the chamber lid125of the chamber body151above the pedestal150. The apertures143of the gas distribution plate142are used to introduce process gases from the gas source193into the chamber body151. The apertures143may have different sizes, number, distributions, shape, design, and diameters to facilitate the flow of the various process gases for different process requirements. A plasma is formed from the process gas mixture exiting the gas distribution plate142to enhance thermal decomposition of the process gases resulting in the deposition of material on the surface191of the substrate190.

The gas distribution plate142and substrate support pedestal150form a pair of spaced apart electrodes in the interior volume126. One or more RF sources147provide a potential through a matching network145to the gas distribution plate142to facilitate generation of a plasma between the gas distribution plate142and the pedestal150. Alternatively, the RF sources147and matching network145are coupled to the gas distribution plate142, substrate support pedestal150, or coupled to both the gas distribution plate142and the substrate support pedestal150. The RF sources147provide about 10 Watts and about 3000 Watts at a frequency of about 30 KHz to about 14 MHz, such as about 13.6 MHz.

Examples of gases that may be supplied from the gas source193may include a silicon-containing gas, fluorine or chlorine containing gas, oxygen-containing gas, hydrogen-containing gas, carbon-containing gas, inert gas and carrier gases. Suitable examples of gases include a silicon-containing gas, such as SiH4, Si2H6, SiF4, SiH2Cl2, Si4H10, Si5H12, tetraethyl orthosilicate (TEOS), (3-aminopropyl)triethoxysilane, triethoxymethylsilane, chloropentamethyldisilane or combination(s) thereof. Example carrier gases (e.g., dilution gas) include nitrogen (N2), argon (Ar), hydrogen (H2), and helium (He). Suitable carbon-containing gases include alkanes (e.g., propane), and alkenes (e.g., acetylene, propylene). Example oxygen containing gases include oxygen (O2), ozone (O3), water vapor (H2O), nitrous oxide, or combination(s) thereof.

The controller110includes a central processing unit (CPU)112, a memory116, and a support circuit114utilized to control the process sequence and regulate the gas flows from the gas source193. The CPU112may be of any form of a general purpose computer processor that may be used in an industrial setting. The software routines can be stored in the memory116, such as random access memory, read only memory, floppy, or hard disk drive, or other form of digital storage. The support circuit114is coupled to the CPU112and may include cache, clock circuits, input/output systems, power supplies, and the like. Bi-directional communications between the controller110and the various components of the processing system132are handled through numerous signal cables collectively referred to as signal buses118, some of which are illustrated inFIG.1.

FIG.2depicts a flow diagram of a seasoning and cleaning method according to an embodiment of the present disclosure. At operation202, a silicon oxide (SiOx) film is deposited over a process chamber component, and/or over interior surfaces of a process chamber. Depositing the silicon oxide includes introducing one or more deposition gases to a process volume of a process chamber. As used herein, the term “silicon oxide” refers to a composition including the formula SiOx, where x is any positive value. In particular, silicon oxide is one or more of silicon dioxide (e.g., quartz), silicon monoxide, non-stoichiometric silicon oxide, silanol (SiOH), or combination(s) thereof.

The deposition gas includes a silicon-containing gas, an oxygen-containing gas, and a dilution gas. The silicon-containing gas is selected from the group consisting of SiH4, Si2H6, SiF4, SiH2Cl2, Si4H10, Si5H12, Tetraethyl orthosilicate (TEOS), (3-aminopropyl)triethoxysilane, triethoxymethylsilane, chloropentamethyldisilane and combination(s) thereof. A ratio of silicon-containing gas (such as silane) to oxygen-containing gas is about 0.007 to about 0.08 by volume. The dilution gas is selected from the group consisting of nitrogen (N2), argon (Ar), hydrogen (H2), helium (He), nitrogen, nitrous oxide, and combination(s) thereof. The oxygen-containing gas is selected from a group consisting of oxygen (O2), ozone (O3), water vapor (H2O), nitrous oxide (e.g., nitrogen monoxide), and combination(s) thereof.

Depositing the silicon oxide film includes flowing the silane-containing gas and the oxygen-containing gas at a silane-containing gas to oxygen-containing gas flow ratio of about 0.008 to about 0.03. In some embodiments, which can be combined with other embodiments described herein, the gases are suppled from the gas source193, or other gas sources (not shown) that are introduced into the process chamber separately, or mixed prior to introducing into the processing system132.

Depositing the silicon oxide film further includes energizing the deposition gas. The RF power sources147,184,186provide radio frequency energy to activate the gases and enable the deposition process. The RF power and gas flow rate is adjusted to deposit silicon oxide film of a specified silicon to oxygen ratio, thereby providing a good adhesion to the subsequent deposited film. Furthermore, the RF power and gas flow rate is adjusted to control the deposition rate of the silicon oxide film, thereby efficiently depositing the silicon oxide film with predetermined properties such as film thickness, film density, and other film quality attributes which are described herein. It has been discovered that a silicon-containing gas flow (sccm) to power (W) ratio of less than 0.07 provides a silicon oxide coating having the predetermined properties described herein.

Energizing the deposition gas forms a silicon oxide (SiOx) film over a process chamber component. A film thickness of the silicon oxide film is about 2 kÅ to about 35 kÅ, such as about 3 kÅ to about 7 kÅ, such as about 5 kÅ. The silicon oxide film is coated on an interior surface of the processing chamber, such as one or more chamber components, such as one or more chamber components functioning as a faceplate, electrodes or chamber component with electrodes embedded therein. Any and all surfaces of any and all chamber components are contemplated, including, but not limited to, a gas distribution plate142(e.g., faceplate with or without an electrode141), a chamber lid125(with or without an electrode121), a pedestal150(with or without an electrode192), a sidewall101, a bottom wall122, or combination(s) thereof. Without being bound by theory, it is believed that energizing gases during film deposition and/or plasma cleaning causes ion sputtering on chamber component surfaces, such as aluminum surfaces. Ion sputtering damage occurs during plasma initiation as well as high energy ion bombardment such as during RF cleaning. It has been discovered that the silicon oxide film that is deposited does not sputter and protects the underlying surface. The silicon oxide film is deposited on surfaces of chamber components as well as within small surface area spaces such as within faceplate orifices.

FIG.3depicts a schematic, cross-sectional side view of a faceplate orifice300according to an embodiment of the present disclosure. The orifice300is substantially cone shaped with an orifice inlet302configured to receive process gasses, and an outlet304in fluid communication with the chamber volume. The method provided herein provides improved coverage of the outer surface of the faceplate and within the interior surface of the orifice as shown by the layer306. The coating covers more than 50% of the interior surface area of the orifice, such as about 50% to about 90%, such as about 80%. Other RF coatings cover less than 50% of the interior surface of the orifice of the faceplate.

In some embodiments, which can be combined with other embodiments described herein, an outer surface of one or more electrodes are coated with the silicon oxide film. The electrodes include powered electrodes, ground electrodes, cathodes, anodes, components including electrodes, and combination(s) thereof. The electrodes are composed of aluminum, aluminum oxide, aluminum carbide, aluminum nitride, alloys thereof, or combinations thereof, such as AIOC, such as AIOCN. In some embodiments, which can be combined with other embodiments described herein, depositing the silicon oxide film includes depositing the silicon oxide film over an electrode141of a distribution plate142composed of AIOC. In some embodiments, which can be combined with other embodiments described herein, depositing the silicon oxide film includes depositing the silicon oxide film over an electrode192of a pedestal150composed of AIOCN.

The silicon oxide film includes one or more of a thickness of about 3 kA to about 7 kA, a refractive index (RI) at 633 nm of about 0.2 to about 0.3, a hydrofluoric acid (HF) wet etch rate thickness of about 70 Angstroms to about 85 Angstroms at a radiofrequency power of about 500 W, an SiOxdensity of about 1.5 g/cc to about 2.6 g/cc, as determined by X-ray reflectrometry, an SiOxhardness of about 5 Gpa to about 8 Gpa, as determined using nanoindentation with Agilent NanoG300 tool conforming to ISO 14577, and an SiOxmodulus of about 50 Gpa to about 90 Gpa, as determined using nanoindentation with Agilent NanoG300 tool conforming to ISO 14577. As used herein HF wet etch rate thickness is measured by dipping a substrate having the silicon oxide film into hydrochloride solution with 100:1 diluted HF for 60 seconds. The HF wet etch rate thickness provides a measure of film quality of the film collected on a substrate during film deposition for test purposes. Although certain physical properties determined herein are measured using the disclosed tools and methods, it is also contemplated to arrive at equivalent physical properties using other methods and tools known in the industry.

A surface roughness (Ra) of the SiOxfilm is about 0.1 nm to about 0.4 nm, determined by measuring a surface roughness of a substrate after forming the film as described herein over the substrate and measuring the roughness based on atomic force microscopy. It is believed that surface roughness correlates to film quality and ability to withstand high energy ion bombardment that is typically used during cleaning processes. The surface roughness of the SiOxfilm is maintained at about 0.1 nm to about 0.4 nm before and after high energy bombardment. Conventional films such as ex situ ALD coatings, or other in situ CVD coatings were found to have surface roughness up to an Ra of about 2.7 nm before high energy ion bombardment and an Ra of below 1.0 after high energy ion bombardment. Thus, the silicon oxide films (e.g., coatings) described herein have higher resistance to high energy ion bombardment as demonstrated by a less than 5%, or less than 3%, or less than 1% change in oxygen concentration after bombardment. In particular, the silicon oxide films have a starting surface roughness that is about 2 times to about 15 times, such as about 5 times to about 10 times lower than the starting surface roughness of conventional coatings. The silicon oxide coatings further demonstrate about 10% to about 20% reduction in wet etch rate, demonstrated by a hydrofluoric acid wet etch test, compared to conventional films. The silicon oxide coating exhibited sufficient emissivity control as demonstrated by a refractive index (RI) at 633 nm of about 0.2 to about 0.3.

Consistent emissivity during, between, and after processing affects process conditions, such as temperature control. A temperature sensor (not shown) such as a thermocouple or a pyrometer is capable of sensing a temperature of the electrode192or the pedestal150and provide the temperature information to feedback temperature control of the controller110. The information is used to determine if power adjustment to the pedestal150is necessary. If emissivity of the silicon oxide coating is not controlled (e.g., changes from run-to-run), temperature control of the substrate is affected and can lead to device property shift or damage after processing a quantity of devices. In some embodiments, which can be combined with other embodiments described herein, a substrate temperature is maintained at about 400° C. to about 650° C., and a pressure of the process volume is maintained at about 0.05 Torr to about 12 Torr.

At operation204, the silicon oxide film is exposed to a carbon deposition process to convert at least a portion of the silicon oxide to a silicon-carbon-containing film. In some embodiments, which can be combined with other embodiments described herein, the entire silicon oxide film is converted to a silicon-carbon-containing film. Alternatively, at least the upper 3 nm to about 5 nm of the silicon oxide film is converted to a silicon carbide compound. The at least about 3 nm to about 5 nm makes up about 1% of the total thickness of the silicon oxide film disposed at an upper surface of the silicon oxide film opposite of the chamber component. The carbon deposition process includes introducing a carbon-containing gas to the process volume to form a silicon-carbon-containing film on the silicon oxide film and/or to convert the silicon oxide film to a silicon-carbon containing film.

The conversion reaction is summarized in Formula 1 and/or Formula 2 below.

Formula 1. Silanol to silicon carbide.
SiOH+C2H2+H·→SiC+H2O+CH2

Formula 2. Silicon dioxide to Silicon Carbide.
SiO2+3C→SiC+2CO

Alternatively, or additionally, the silicon oxide is converted to a silicon oxycarbide (SiOC). The carbon-containing gas is composed of hydrocarbons such as, alkanes (e.g., ethane, propane), alkenes (e.g., acetylene, propylene), mixtures thereof, or combination(s) thereof. The carbon-containing gas includes a carrier gas such as hydrogen gas, helium gas, argon gas, nitrogen gas, combination(s) thereof. The gases can be energized using an RF frequency of about 10 MHz to about 14 MHz, such as about 13.6 mHz.

The silicon-carbon-containing film has one or more of a density of about 2.0 g/cc to about 4.5 g/cc, as determined by X-ray reflectrometry, a hardness of about 15 Gpa to about 30 Gpa, as determined using nanoindentation with Agilent NanoG300 tool conforming to ISO 14577, an oxygen concentration of about 65 atomic % to about 66.2 atomic %, and a modulus of about 400 Gpa to about 515 Gpa, as determined using nanoindentation with Agilent NanoG300 tool conforming to ISO 14577. The high modulus, hardness, and density of the silicon carbide film provides a protective barrier over the chamber component resistant to high ion bombardment. Operation204includes an oxygen etch process that releases compounds such as water vapor, carbon monoxide, carbon dioxide, and/or volatile components that are purged from the process volume. In some embodiments, which can be combined with other embodiments described herein, the oxygen etch process uses oxygen plasma.

At operation204, a substrate190is processed in the process chamber with the coated process chamber component. In some embodiments, which can be combined with other embodiments described herein, processing the substrate includes depositing a carbon-containing film over a substrate disposed in the chamber. In some embodiments, which can be combined with other embodiments described herein, operation204and operation206occur at least partially simultaneously such that a carbon-containing film is deposited over the substrate and the silicon oxide film over the chamber component is converted to a silicon carbide simultaneously.

At operation208, the coated process chamber component is cleaned using a fluorine-based RF cleaning process. The cleaning process includes supplying a cleaning gas mixture to the processing system132to clean the interior of the plasma processing chamber, including one or more coated chamber components, such as coated electrodes. The cleaning gas mixture includes at least a fluorine-containing gas. The fluorine-containing gas may also include a carrier gas, such as a nonreactive gas, such as an inert gas. The fluorine-containing gas in the cleaning gas mixture is selected from a group consisting of NF3, SF6, HF, CF4, mixtures thereof, and combination(s) thereof. The carrier gas is helium, argon, or combinations thereof. The cleaning gas is any suitable dry etch composition. The cleaning gas is energized to a plasma using RF power and is capable of removing contaminants disposed in the process chamber. The silicon carbide and/or silicon oxide coated components described herein, are resistant to the cleaning plasma.

In addition, the silicon carbide or silicon oxycarbide films described herein are self-renewing. During a deposition process, such as when forming a carbon hardmask on a substrate, the carbon-containing precursors gas reacts with the silicon oxide chamber seasoning to form silicon carbide or silicon oxycarbide. During subsequent cleaning processes, if any carbon is removed by the cleaning chemistry, the carbon will be replaced in a subsequent deposition processes following the cleaning. In such a manner, the integrity of the seasoning material (e.g., the silicon carbide or the silicon oxycarbide) is maintained significantly longer than conventional seasoning films.

In summation, method for coating a surface of a chamber component, such as an electrode and/or a component having an electrode is provided. The coating is resistant to cleaning processes, has good emissivity control, and reduces risk of device property drift.

Certain features, structures, compositions, materials, or characteristics described herein is combined in any suitable manner in one or more embodiments. Although the present disclosure herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the method and systems of the present disclosure. Thus it is intended that the present disclosure include modifications and variations that are within the scope of the appended claims and their equivalents.