Controlling fluorine diffusion in pecvd silicon nitride process

Abstract

A method for controlling fluorine diffusion during plasma enhanced chemical vapor deposition (PECVD) of silicon nitride is disclosed. The process involves forming a chamber seasoning layer including silicon oxide and / or silicon nitride over aluminum-containing surfaces in the processing chamber after fluorine-based cleaning. The seasoning layer is then treated with hydrogen plasma, passivating silicon dangling bonds and blocking fluorine diffusion pathways. By reducing fluorine contamination in the films that are deposited afterward, this method enhances film quality, boosts device electrical performance, and increases manufacturing yield.

Description

CONTROLLING FLUORINE DIFFUSION IN PECVD SILICON NITRIDE PROCESS TECHNICAL FIELD

[0001] Embodiments of the present disclosure generally relate to improved methods of controlling a processing chamber during normal use and / or during fault conditions to reduce contamination of substrates processed therein.BACKGROUND

[0002] Plasma processing reactors used in the semiconductor industry are often made of aluminum-containing materials for processing performance and / or cost reasons. After processing a number of substrates, or wafers, in the processing region of a processing chamber it is commonly required that the processing region needs to be cleaned by use of an in-situ cleaning process. Typically, during an in-situ cleaning process that uses a fluorinated cleaning gas to clean the processing environment, aluminum fluoride is generated on the surface of the exposed aluminum-containing parts. The aluminum fluoride layer formation during the regularly performed in-situ cleaning processes continually etches the surface of the aluminum-containing parts. In addition, the deposition of aluminum fluoride on the process chamber components can lead to particle problems, fluorine contamination of subsequently deposited films, processing tool down time, and process drift.

[0003] Accordingly, there is a need for a method of preparing the processing region of a process chamber for sequentially processing multiple substrates at high temperatures without the need to frequently take the processing chamber down to remove the unwanted contamination described above.SUMMARY

[0004] In one aspect, a method of controlling fluorine diffusion during a plasma enhanced chemical vapor deposition (PECVD) deposition process is provided. The method includes exposing a chamber seasoning layer formed over one or more interior surfaces of a processing chamber to a hydrogen plasma treatment.44025601 wool

[0005] Implementations of the aforementioned aspects may include one or more of the following. Performing a chamber cleaning process in the processing chamber using a cleaning gas including fluorine prior to exposing the chamber seasoning layer. The chamber cleaning process forms an aluminum fluoride layer on the one or more interior surfaces. Forming the chamber seasoning layer over the one or more interior surfaces after the chamber cleaning process and prior to exposing the chamber seasoning layer to the hydrogen plasma treatment. The chamber seasoning layer is a silicon-containing seasoning layer and the one or more interior surfaces include an aluminum chamber component. The chamber seasoning layer includes a first chamber seasoning layer formed adjacent to the one or more interior surfaces of the processing chamber and a second chamber seasoning layer formed on the first chamber seasoning layer. The first chamber seasoning layer is a silicon oxide and the second chamber seasoning layer is a silicon nitride. The hydrogen plasma treatment includes generating a hydrogen plasma from a process gas including hydrogen and an inert.

[0006] In another aspect, a method for reducing fluorine-induced defects in a plasma enhanced chemical vapor deposition (PECVD) process is provided. The method includes depositing a silicon-containing seasoning layer over an aluminum fluoride layer formed on an interior surface of a processing chamber. The method further includes treating the seasoning layer with a hydrogen plasma to passivate silicon dangling bonds.

[0007] Implementations of the aforementioned aspects may include one or more of the following. The silicon-containing seasoning layer includes a bilayer structure including a silicon oxide layer and a silicon nitride layer. The seasoning layer is deposited by a PECVD process at a temperature between about 200°C and about 400°C. The hydrogen plasma passivates silicon dangling bonds at an interface between the silicon oxide layer and the silicon nitride layer. The aluminum fluoride layer is formed by exposing the interior surface to a fluorine-containing cleaning gas selected from NF3, CF4, and C2F6. Treating the seasoning layer with a hydrogen plasma is performed periodically to refresh the seasoning layer after a predetermined number of substrates are44025601 woolprocessed. The seasoning layer has a thickness between about 2 micrometers and about 20 micrometers.

[0008] In yet another aspect, a method for reducing fluorine-induced defects in a plasma enhanced chemical vapor deposition (PECVD) process is provided. The method includes exposing a chamber seasoning layer formed over one or more interior surfaces of a processing chamber to a hydrogen plasma treatment. The method further includes positioning a substrate in a processing volume defined by the processing chamber subsequent to the hydrogen plasma treatment. The method further includes depositing a silicon nitride film on the substrate within the processing volume, wherein the hydrogen plasma treatment reduces fluorine incorporation into the subsequently deposited silicon nitride film.

[0009] Implementations of the aforementioned aspects may include one or more of the following. The chamber seasoning layer includes a silicon oxide layer formed adjacent to the one or more interior surfaces and a silicon nitride layer formed on the silicon oxide layer. An aluminum fluoride layer is formed between the one or more interior surfaces and the silicon oxide layer. The hydrogen plasma treatment passivates silicon dangling bonds at an interface between the silicon oxide layer and the silicon nitride layer. The aluminum fluoride layer is formed by exposing the one or more interior surfaces to a fluorine-containing cleaning gas selected from NF3, CF4, and C2F6.

[0010] In another aspect, a non-transitory computer readable medium has stored thereon instructions, which, when executed by a processor, causes the process to perform operations of the above apparatus and / or method.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplaryembodiments and are therefore not to be considered limiting of its scope, and may admit to other equally effective embodiments.

[0012] FIG. 1 is a schematic illustration of an example process chamber that can be used for the practice of the method depicted in FIG. 2, in accordance with one or more embodiments of the present disclosure.

[0013] FIG. 2 illustrates an exemplary flow chart of a method in accordance with one or more embodiments of the present disclosure.

[0014] FIGS. 3A-3D illustrate schematic side views of various stages of manufacturing a semiconductor device according to the method of FIG. 2 in accordance with one or more embodiments of the present disclosure.DETAILED DESCRIPTION

[0015] Embodiments of the present disclosure generally relate to improved methods of controlling a processing chamber during normal use and / or during fault conditions to reduce contamination of substrates processed therein.

[0016] Unwanted deposition of materials (e.g., dielectric materials) on the interior aluminum-containing surfaces such as the walls and chamber parts of plasma-enhanced chemical vapor deposition (PECVD) processing chambers may occur during deposition processes. Such unwanted deposition may create particles and flakes within the chamber, resulting in the drift of process conditions and more importantly affecting process reproducibility and uniformity.

[0017] In order to achieve high chamber availability while reducing the cost of ownership for production and maintaining film quality, a chamber clean is typically used to remove material residue from the aluminum-containing interior surfaces of the processing chamber including the wall and process kits, e.g., showerhead, etc. Currently, reactive fluorine-species (e.g., fluorine radicals) are used to remove unwanted deposits. Unfortunately, most current chamber cleaning processes adversely affect the interior surfaces of the processing chamber resulting in the production of additional particles and flakes. For example, during fluorine radical cleaning, the fluorine radicals attach to thealuminum-containing surfaces (e.g., aluminum nitride surface) of the heater and convert the aluminum nitride to aluminum fluoride. Generally, the aluminum fluoride deposits start to sublime at about 480 degrees Celsius. Then, the aluminum fluoride condenses and forms a layer on the faceplate / showerhead. The aluminum fluoride deposits can flake off and fall on the wafer during process adversely affecting the yield. Hence, aluminum fluoride particles (defects) on the wafer have very tight specifications since they affect the yield significantly. Moreover, with ever tightening specifications for particles it is better to have no aluminum fluoride on the heater or faceplate.

[0018] In one or more embodiments, the method described herein includes a hydrogen plasma treatment of a SiO / SiN chamber seasoning film to reduce the diffusion of fluorine from underlying AIF3 material formed on chamber parts into the material being deposited in the processing chamber. This improves the quality of the deposited PECVD silicon nitride film by minimizing fluorine contamination which can have adverse effects to subsequent chip manufacturing steps and device electrical performance.

[0019] The hydrogen plasma treatment process can be an inductively coupled plasma (ICP) process or a capacitively coupled plasma (CCP) process. The plasma can be formed ex-situ in a remote plasma source (RPS). The plasma can be a direct plasma formed in-situ, for example, generated within a processing region. In one or more embodiments, which can be combined with other embodiments, the plasma is formed from a process gas including a hydrogen-containing gas. The process gas may further include an inert gas, for example, argon (Ar), helium (He), krypton (Kr), or a combination thereof. The inert gas helps stabilize the plasma. In one or more embodiments, the hydrogen plasma treatment process includes a plasma formed form a process gas including hydrogen and argon.

[0020] During hydrogen plasma treatment process, the RF source can have a power in a range from about 10 W to about 10 kW, or in a range from about 100 W to about 1500 W, or in a range from about 100 W to about 500 W, or in a range from about 200 W to about 400 W, or in a range from about 400 W to about 500 W. The RF source may include a high frequency radio frequency(HFRF) power source, e.g., a 13.56 MHz RF generator, and / or a low frequency radio frequency (LFRF) power source, e.g., a 300 kHz RF generator.

[0021] Not to be bound by theory, but it is believed that the hydrogen plasma treatment described herein is effective at passivating dangling bonds and inducing ion bombardment to block fluorine diffusion pathways.

[0022] FIG. 1 illustrates a cross-sectional view of an exemplary processing chamber 100, according to certain embodiments of the present disclosure. FIG.1 provides an overview of a system incorporating one or more aspects of the present disclosure, and / or which may perform one or more deposition or other processing operations according to embodiments of the present disclosure. Suitable chambers may be obtained from Applied Materials, Inc. located in Santa Clara, Calif. It is to be understood that the system described below is an exemplary process chamber and other chambers, including chambers from other manufacturers, may be used with or modified to accomplish embodiments of the present disclosure (e.g., method 200 described below). Additional details of the processing chamber 100 or methods performed may be described further below. The processing chamber 100 may be utilized to form film layers, e.g., for gap-filling, according to certain embodiments of the present disclosure, although it is to be understood that the methods may similarly be performed in any chamber within which film formation may occur. In certain embodiments, the processing chamber 100 is a PECVD chamber.

[0023] The processing chamber 100 may include a chamber body 102, a substrate support 104 disposed inside the chamber body 102, and a lid assembly 106 coupled with the chamber body 102 and enclosing the substrate support 104 in a processing volume 120. A substrate 103 may be provided to the processing volume 120 through an opening 126, which may be conventionally sealed for processing using a slit valve or door. The substrate 103 may be seated on a surface 105 of the substrate support 104 during processing. The substrate support 104 may be rotatable, as indicated by the arrow 145, along an axis 147, where a shaft 144 of the substrate support 104 may be located. Alternatively, the substrate support 104 may be lifted to rotate, as necessary, during a deposition process. Additionally, the substrate support104 include a cooling device and may be configured to be chilled, e.g., less than or about 100°C, or less than or about 90°C, or less than or about 80°C, or less than or about 70°C, or less than or about 60°C, or less than or about 50°C, or less than or about 40°C, or less than or about 30°C, or less than or about 20°C, or less than or about 10°C, or less.

[0024] A plasma profile modulator 111 may be disposed in the processing chamber 100 to control plasma distribution across the substrate 103 disposed on the substrate support 104. The plasma profile modulator 111 may include a first electrode 108 that may be disposed adjacent to the chamber body 102 and may separate the chamber body 102 from other components of the lid assembly 106. The first electrode 108 may be part of the lid assembly 106 or may be a separate sidewall electrode. The first electrode 108 may be an annular or ring-like member and may be a ring electrode. The first electrode 108 may be a continuous loop around a circumference of the processing chamber 100 surrounding the processing volume 120 or may be discontinuous at selected locations if desired. The first electrode 108 may also be a perforated electrode, such as a perforated ring or a mesh electrode, or may be a plate electrode, such as, for example, a secondary gas distributor.

[0025] One or more isolators 110a, 110b, which may be a dielectric material such as a ceramic or metal oxide, for example aluminum oxide and / or aluminum nitride, may contact the first electrode 108 and separate the first electrode 108 electrically and thermally from a gas distributor 112 and from the chamber body 102.

[0026] The gas distributor 112 may define apertures 118 for distributing process precursors into the processing volume 120. The gas distributor 112 may be a conductive gas distributor or a non-conductive gas distributor. Accordingly, the gas distributor 112 may be formed of conductive and non-conductive components. For example, a body of the gas distributor 112 may be conductive while a faceplate of the gas distributor 112 may be non-conductive. The gas distributor 112 may be powered, such as by a first source of electric power 142 as shown in FIG. 1, or the gas distributor 112 may be coupled with ground in certain embodiments.

[0027] The gas distributor 112 may be coupled with a first source of electric power 142, such as a continuous or pulsed radio frequency (RF) power source (i.e. , an RF generator), a continuous or pulsed direct current (DC) power source (i.e., a DC generator), any other power source that can be coupled with the processing chamber 100, or a combination of these or other power sources. In certain embodiments, the first source of electric power 142 generates and provides RF bias power to the gas distributor 112. In such embodiments, the first source of electric power 142 is configured to generate a continuous or pulsed RF bias at low frequencies (low frequency RF (LFRF)), such as between about 350 kHz and about 2 MHz, and / or high frequencies (high frequency RF (HFRF), such as between about 13. 56 MHz and about 2 MHz. The gas distributor 112 may be coupled with the first source of electric power 142 through a filter 158, which may be an impedance matching circuit.

[0028] The first electrode 108 may be coupled with a first tuning circuit 128 that may control a ground pathway of the processing chamber 100. The first tuning circuit 128 may include a first electronic sensor 130 and a first electronic controller 134. The first electronic controller 134 may be or include a variable capacitor or other circuit elements. The first tuning circuit 128 may be or include one or more inductors 132. The first tuning circuit 128 may be any circuit that enables variable or controllable impedance under the plasma conditions present in the processing volume 120 during processing. In certain embodiments as illustrated, the first tuning circuit 128 may include a first circuit leg and a second circuit leg coupled in parallel between ground and the first electronic sensor 130. The first circuit leg may include a first inductor 132A. The second circuit leg may include a second inductor 132B coupled in series with the first electronic controller 134. The second inductor 132B may be disposed between the first electronic controller 134 and a node connecting both the first and second circuit legs to the first electronic sensor 130. The first electronic sensor 130 may be a voltage or current sensor and may be coupled with the first electronic controller 134, which may afford a degree of closed-loop control of plasma conditions inside the processing volume 120.

[0029] A second electrode 122 may be coupled with the substrate support 104. The second electrode 122 may be embedded within the substrate support 104 or coupled with a surface of the substrate support 104. The second electrode 122 may be a plate, a perforated plate, a mesh, a wire screen, or any other distributed arrangement of conductive elements. The second electrode 122 may be a tuning electrode and may be coupled with a second tuning circuit 136 by a conduit 146, for example a cable having a selected resistance, such as 50 ohms, for example, disposed in the shaft 144 of the substrate support 104. The second tuning circuit 136 may have a second electronic sensor 138 and a second electronic controller 140, which may be a second variable capacitor. The second electronic sensor 138 may be a voltage or current sensor and may be coupled with the second electronic controller 140 to provide further control over plasma conditions in the processing volume 120.

[0030] In certain embodiments, a third electrode 124, which may be an electrostatic chucking electrode and / or a bias electrode, may be coupled with the substrate support 104. The third electrode may be coupled with a second source of electric power 150 through a filter 148, which may be an impedance matching circuit. The second source of electric power 150 may be a continuous or pulsed DC power source, a continuous or pulsed RF power source, or a combination of these or other power sources. In certain embodiments, the second source of electric power 150 may be configured to generate an RF bias power (e.g., configured to provide a continuous or pulsed RF bias at low frequencies, such as between about 350 kHz and about 2 MHz, and / or high frequencies, such as between about 13. 56 MHz and about 2 MHz).

[0031] The lid assembly 106 and substrate support 104 of FIG. 1 may be used with any processing chamber for plasma or thermal processing. In operation, the processing chamber 100 may afford real-time control of plasma conditions in the processing volume 120. The substrate 103 may be disposed on the substrate support 104, and process gases may be flowed through the lid assembly 106 using an inlet 114 according to any desired flow plan. Inlet 114 may include delivery from a remote plasma source unit 116, which may be fluidly coupled with the chamber, as well as a bypass 117 for process gasdelivery that may not flow through the remote plasma source unit 116 in certain embodiments. Gases may exit the processing chamber 100 through an outlet 152. Electric power may be coupled with the gas distributor 112 to establish a plasma in the processing volume 120.

[0032] Upon energizing a plasma in the processing volume 120, a potential difference may be established between the plasma and the gas distributor 112, the first electrode, and / or the second electrode 122. The electronic controllers 134, 140 may then be used to adjust the flow properties of the ground paths represented by the two tuning circuits 128 and 136. A set point may be delivered to the first tuning circuit 128 and the second tuning circuit 136 to provide independent control of deposition rate and of plasma density uniformity from center to edge. In embodiments where the electronic controllers may both be variable capacitors; the electronic sensors may adjust the variable capacitors to maximize deposition rate and minimize thickness non-uniform ity independently.

[0033] Each of the tuning circuits 128, 136 may have a variable impedance that may be adjusted using the respective electronic controllers 134, 140. Where the electronic controllers 134, 140 are variable capacitors, the capacitance range of each of the variable capacitors, and the inductances of the first inductor 132A and the second inductor 132B, may be chosen to provide an impedance range. This range may depend on the frequency and voltage characteristics of the plasma, which may have a minimum in the capacitance range of each variable capacitor. Hence, when the capacitance of the first electronic controller 134 is at a minimum or maximum, impedance of the first tuning circuit 128 may be high, resulting in a plasma shape that has a minimum aerial or lateral coverage over the substrate support. When the capacitance of the first electronic controller 134 approaches a value that minimizes the impedance of the first tuning circuit 128, the aerial coverage of the plasma may grow to a maximum, effectively covering the entire working area of the substrate support 104. As the capacitance of the first electronic controller 134 deviates from the minimum impedance setting, the plasma shape may shrink from the chamber walls and aerial coverage of the substrate support may decline. Thesecond electronic controller 140 may have a similar effect, increasing and decreasing aerial coverage of the plasma over the substrate support as the capacitance of the second electronic controller 140 may be changed.

[0034] The electronic sensors 130, 138 may be used to tune the respective circuits 128, 136 in a closed loop. A set point for current or voltage, depending on the type of sensor used, may be installed in each sensor, and the sensor may be provided with control software that determines an adjustment to each respective electronic controller 134, 140 to minimize deviation from the set point. Consequently, a plasma shape may be selected and dynamically controlled during processing. It is to be understood that, while the foregoing discussion is based on electronic controllers 134, 140, which may be variable capacitors, any electronic component with adjustable characteristic may be used to provide tuning circuits 128 and 136 with adjustable impedance.

[0035] Processing chamber 100 may be utilized in certain embodiments of the present disclosure for processing methods that may include formation, treatment, etching, or conversion of materials for semiconductor structures. It is to be understood that the chamber described is not to be considered limiting, and any chamber that may be configured to perform operations as described may be similarly used.

[0036] One or more interior surfaces (e.g., the chamber body 102, the substrate support 104, the lid assembly 106, the gas distributor 112) of the processing chamber 100 can be or include aluminum.

[0037] Other deposition chambers may also benefit from the present disclosure and the parameters listed above may vary according to the particular deposition chamber used to form the amorphous carbon layer. For example, other deposition chambers may have a larger or smaller volume, requiring gas flow rates that are larger or smaller than the gas flow rates recited for deposition chambers available from Applied Materials, Inc.

[0038] FIG. 2 illustrates an exemplary flow chart of a method 200 in accordance with one or more embodiments of the present disclosure. FIGS.3A-3D illustrate schematic side views of various stages of manufacturing a semiconductor device according to the method of FIG. 2 in accordance with one or more embodiments of the present disclosure. Although FIGS. 3A-3D are described in relation to the method 200, it will be appreciated that the various stages disclosed in FIGS. 3A-3D are not limited to the method 200 but instead may stand alone as structures independent of the method 200. Similarly, although the method 200 is described in relation to FIGS. 3A-3D, it will be appreciated that the method 200 is not limited to the various stages disclosed in FIGS. 3A-3D but instead may stand alone independent of the various stages disclosed in FIGS. 3A-3D. FIGS. 3A-3D illustrate only partial schematic views of various stages of processing a semiconductor device structure, and the various stages may contain any number of additional elements and / or additional materials common to semiconductor device structures, which are not shown for the sake of brevity. It should also be noted that although the method 200 illustrated in FIG. 2 is described sequentially, other process sequences that include one or more operations that have been omitted and / or added, and / or have been rearranged in another desirable order, fall within the scope of the embodiments of the disclosure provided herein. The method 200 may be performed using any suitable plasma deposition system. In one or more embodiments, the method 200 or parts of the method 200 are performed in the processing chamber 100.

[0039] Referring to FIG. 3A, at operation 210 a chamber cleaning process is performed. The chamber cleaning process includes contacting one or more interior surfaces of the process chamber with a plasma cleaning gas. FIG. 3A depicts a processing chamber 300 defining a processing volume 310. The processing chamber includes at least one chamber component 330. The chamber component 330 includes at least one surface that is or includes an aluminum-containing surface. An aluminum fluoride layer 340 is formed on the chamber component 330 after exposure to a chamber cleaning process.

[0040] At operation 210 the processing volume of the process chamber is exposed to a plasma cleaning process. The chamber clean process may be performed by introducing fluorine-containing gases and oxidizing gases into the44025601 woolprocessing volume 310 either as a process gas mixture or separately. Any suitable fluorine-containing gas may be used. Examples of suitable fluorine-containing gases include but are not limited to NF3, CF4, C2F6, or combinations thereof. In one or more embodiments, the chamber clean process is performed by introducing NF3 and optionally an inert gas such as argon or helium into the processing volume 310 and striking a plasma in the processing volume 310 according to methods known in the art to remove material deposited on the chamber walls and chamber components from the previous deposition process. In one or more other embodiments, the plasma is formed by a remote plasma source (RPS) and delivered to the processing volume 310. Optionally, one or more inert gases can be included with the gases used to perform the plasma cleaning process. Suitable inert gases include but are not limited to argon, helium, or combinations thereof.

[0041] At operation 220, an optional purging / evacuation process of the processing volume 310 of the processing chamber 300 may be performed to remove the gaseous reaction products formed between the cleaning gases and the deposition material and contaminants present within the chamber. In one or more embodiments, plasma may be applied during the optional purge / evacuation process of operation 220.

[0042] Referring to FIG. 3A, at operation 230 a season layer deposition process is performed. The season layer deposition process includes depositing a chamber seasoning layer 350 on the aluminum fluoride layer 340. The chamber seasoning layer 350 prevents or reduces the diffusion of fluorine from the aluminum fluoride layer 340 into the processing volume 310, where the fluorine can contaminate the substrate 320 and / or films subsequently deposited on the substrate 320, for example, silicon nitride films deposited by a plasma enhanced chemical vapor deposition (PECVD) process. In one or more embodiments the chamber seasoning layer 350 is or includes a silicon oxide layer, a silicon nitride layer, or a bi-layer seasoning layer including a silicon oxide layer and a silicon nitride layer. In one or more embodiments, the chamber seasoning layer 350 includes a first seasoning layer 360, which is formed on the aluminum fluoride layer 340. The first seasoning layer 360 can44025601 woolbe or include silicon oxide, for example, SiO2. The silicon oxide can be deposited by a PECVD process that includes flowing TEOS or silane, oxygen, and a carrier gas such as helium or argon. In one example, the PECVD process for depositing silicon oxide is performed at a temperature in a range from about 200 °C to about 400 °C, a pressure in a range from about 0.8 torr to about 4 torr, an RF power in a range from about 100 W to about 1 ,000 W at a frequency of 13.56 MHz. The first seasoning layer 360 can have a thickness in a range from about 2 pm to about 20 pm. The chamber seasoning layer 350 further includes a second seasoning layer 370 formed on the first seasoning layer. The second seasoning layer 370 can be or include silicon nitride, for example, Si3N4. The silicon nitride can be deposited by a PECVD process that includes flowing NH3, N2, or N2O, silane, and a carrier gas such as helium or argon. In one example, the PECVD process for depositing silicon nitride is performed at a temperature in a range from about 200 °C to about 400 °C, a pressure in a range from about 0.8 torr to about 4 torr, an RF power in a range from about 100 W to about 1 ,000 Wat a frequency of 13.56 MHz. The second seasoning layer 360 can have a thickness in a range from about 2 pm to about 20 pm.

[0043] In one or more embodiments, fluorine diffuses from the aluminum fluoride layer 340 through the chamber seasoning layer 350 onto the surface of the chamber seasoning layer 350. The concentration gradient of fluorine atoms is believed to be the driving force for fluorine diffusion. Not to be bound by theory but it is believed that fluorine diffuses through silicon bonds. The factors driving diffusion through silicon dangling bonds are believed to include the concentration of dangling bonds, the density / porosity (# of oxygen vacancies), and the activation energy for fluorine diffusion. Factors driving interstitial diffusion are believed to include the size of fluorine vs the size of Si / O atoms, interatomic spacing, density and film stress. The silicon dangling bonds on the surface of the second seasoning layer 370 are believed to function as sites for the diffusion of fluorine onto the substrate 320. It is also believed that dangling bonds at thin film interfaces, for example, the interface of the first seasoning layer 360 and the second seasoning layer 370 can function as available sites for fluorine diffusion.

[0044] At operation 240, an optional purging / evacuation process of the processing volume 310 of the processing chamber 300 may be performed to remove the gaseous reaction products formed between the cleaning gases and the deposition material and contaminants present within the chamber. In one or more embodiments, plasma may be applied during the optional purge / evacuation process of operation 240.

[0045] Referring to FIG. 3B and 3C, at operation 250, a hydrogen plasma passivation process is performed. The hydrogen plasma passivation process includes exposing the chamber seasoning layer 350 to a hydrogen plasma to passivate dangling silicon bonds in the chamber seasoning layer 350 to control fluorine diffusion. FIG. 3B demonstrates the hydrogen passivation of silicon dangling bonds at the interface of the first seasoning layer 360 and the second seasoning layer 370 using hydrogen radicals 390 from the hydrogen plasma treatment process described herein. FIG. 3C demonstrates the hydrogen passivation of silicon dangling bonds at the surface of the second seasoning layer 370 using hydrogen radicals 390 from the hydrogen plasma treatment process described herein. Silicon dangling bonds may be present at the SiO2 / Si3N4 interface and / or the Si3N4 surface. Hydrogen passivation of Si dangling bonds prevents or reduces Si-F bond formation and diffusion onto the substrate 320.

[0046] The hydrogen plasma treatment process can be an inductively coupled plasma (ICP) process or a capacitively coupled plasma (CCP) process. The plasma can be formed ex-situ in a remote plasma source (RPS). The plasma can be a direct plasma formed in-situ, for example, generated within a processing region. In one or more embodiments, which can be combined with other embodiments, the plasma is formed from a process gas including a hydrogen-containing gas. In one or more embodiments, the hydrogencontaining gas is or includes hydrogen (H2), deuterium (D2), NH3, or a combination thereof. The process gas may further include an inert gas, for example, argon (Ar), helium (He), krypton (Kr), nitrogen (N2), or a combination thereof. The inert gas helps stabilize the plasma. In one or more embodiments,the hydrogen plasma treatment process includes a plasma formed form a process gas including hydrogen and argon.

[0047] During hydrogen plasma treatment process, the RF source can have a power in a range from about 10 W to about 10 kW, or in a range from about 100 W to about 1500 W, or in a range from about 100 W to about 500 W, or in a range from about 200 W to about 400 W, or in a range from about 400 W to about 500 W. The RF source may include a high frequency radio frequency (HFRF) power source, e.g., a 13.56 MHz RF generator, and / or a low frequency radio frequency (LFRF) power source, e.g., a 300 kHz RF generator.

[0048] In one or more embodiments, operation 250 includes delivering one or more gases to the processing region of the semiconductor processing chamber including the chamber seasoning layer 350 to form a treatment gas mixture. A plasma may be formed from the treatment gas mixture. The plasma may be formed within the processing region, such as by applying plasma power to the faceplate as previously described. In one or more embodiments, however, the plasma may be formed external to the processing region, such as by a remote plasma source (e.g., remote plasma source unit 116 described above), and delivered to the processing region.

[0049] In one or more embodiments, a flow rate of the hydrogen-containing gas is greater than or about 50 seem, or greater than or about 75 seem, or greater than or about 100 seem, or greater than or about 250 seem, or greater than or about 500 seem, or greater than or about 750 seem, or greater than or about 1000 seem, or greater than or about 2000 seem, or greater than or about 3000 seem, or greater than or about 4000 seem, or greater than or about 5000 seem, or greater than or about 6000 seem, or more. In one or more embodiments, a flow rate of helium, argon, xenon, krypton, nitrogen, and / or other diluent(s) is greater than or about 100 seem, or greater than or about 500 seem, or greater than or about 1000 seem, or greater than or about 2000 seem, or greater than or about 3000 seem, or greater than or about 4000 seem, or greater than or about 5000 seem , or greater than or about 6000 seem , or greater than or about 7000 seem, or greater than or about 8000 seem, or greater thanor about 9000 seem, or greater than or about 10000 seem, or greater than or about 11000 seem, or greater than or about 12000 seem, or more.

[0050] The source power applied to generate and sustain a plasma during the hydrogen plasma passivation process of operation 250 may be a lower source power, which may limit dissociation, and which may maintain an amount of hydrogen incorporation in the deposited materials. Additionally, unlike conventional technologies, the present technology may incorporate RF biasing, including a low frequency radio frequency (LFRF) bias, and in certain embodiments, a high frequency RF (HFRF) bias which may facilitate treatment of the chamber seasoning layer 350. Thus, operation 250 may include utilizing a source power, such as coupled with the faceplate or showerhead as previously described, as well as utilizing a bias power, such as applied through the faceplate or showerhead (e.g., a top feed bias), or the substrate support (e.g., a bottom feed bias), as discussed above.

[0051] In one or more embodiments, a source power (e.g., as generated and applied to the faceplate or showerhead by the first source of electric power 142), may be pulsed, and the duty cycle may be reduced, which may further reduce the effective plasma power. For example, the source power may be applied at any higher frequency, such as greater than or about 10 MHz, greater than or about 13 MHz, greater than or about 15 MHz, greater than or about 20 MHz, or higher. The source power may be less than or about 300 W, or less than or about 250 W, or less than or about 200 W, or less than or about 150 W, or less than or about 100 W, or less than or about 50 W, or less. Additionally, the source power may be pulsed at a pulsing frequency of 20 kHz or less, such as less than or about 15 kHz, or less than or about 12 kHz, or less than or about 10 kHz, or less than or about 8 kHz, or less. Additionally, the pulsing duty cycle may be applied at less than or about 50%, and may be applied at less than or about 40%, or less than or about 30%, or less than or about 20%, or less than or about 10%, or less than or about 5%, or less than or about 1 % or less.

[0052] In one or more embodiments, a bias power may be generated and applied to the faceplate or showerhead by the first source of electric power 142 or to the substrate support by the second source of electric power 150. Thebias power may be provided at a low frequency radio frequency (LFRF), such as less than or about 2 MHz, or less than or about 1.5 MHz, or less than or about 1 MHz, or less than or about 750 kHz, or less than or about 500 kHz, or less than or about 450 kHz, or less than or about 400 kHz, or less than or about 350 kHz, or less. The LFRF bias power may have a power of less than or about 900 W, or less than or about 600 W, or less than or about 300 W, or less than or about 200 W, or less than or about 100 W, or less than or about 50 W, or less. In certain embodiments, the LFRF bias power is applied at a power of about 100 W to about 900 W. Additionally, the LFRF bias power may be pulsed at a pulsing frequency of 2 kHz or less, such as less than or about 1.5 kHz, or less than or about 1 kHz, or less than or about 900 Hz, or less than or about 800 Hz, or less than or about 700 Hz, or less than or about 600 Hz, or less than or about 500 Hz, or less than or about 400 Hz, or less than or about 300 Hz, or less than or about 200 Hz, or less than or about 100 Hz, or less. In one or more embodiments, the pulse frequency is between about 200 Hz and about 2 kHz. Additionally, the pulsing duty cycle of the LFRF bias power may be applied at less than or about 80%, or less than or about 70%, or less than or about 60%, or less than or about 50%, or less than or about 40%, or less than or about 30%, or less than or about 20%, or less than or about 10%, or less than or about 6%, or less than or about 5%, or less than or about 1 %, or less. In certain embodiments, the duty cycle is between about 10% and about 70%.

[0053] In one or more embodiments, dual-frequency biasing may be performed at operation 250. In such embodiments, a second bias power may be generated and applied to the faceplate or showerhead by the first source of electric power 142 or to the substrate support by the second source of electric power 150. The second bias power may be provided at a higher RF frequency than the LFRF bias power (e.g., at a high frequency radio frequency (HFRF)), such as greater than or about 10 MHz, greater than or about 13 MHz, greater than or about 15 MHz, greater than or about 20 MHz, greater than or about 27 MHz, or higher. The HFRF bias may have a power of more than or about 800 W, or more than or about 1000 W, or more than or about 1200 W, or more than or about 1400 W, or more than or about 1600 W, or more than or about 1800 W, or more than or about 2000 W, or more than or about 2200 W, or more thanor about 2400 W, or more than or about 2600 W, or more than or about 2800 W, or more than or about 2900 W, or more. In certain embodiments, the HFRF bias power is applied at a power of about 800 W to about 2000 W Additionally, the HFRF bias power may be pulsed at a pulsing frequency of 20 kHz or less, such as less than or about 15 kHz, or less than or about 12 kHz, or less than or about 10 kHz, or less than or about 8 kHz, or less than or about 6 kHz, or less than or about 4 kHz, or less than or about 2 kHz, or less. Additionally, the pulsing duty cycle of the HFRF bias may be applied at less than or about 50% and may be applied at less than or about 40%, or less than or about 30%, or less than or about 20%, or less than or about 10%, or less than or about 5%, or less than or about 1 % or less.

[0054] In one or more embodiments, a LFRF bias power and / or a HFRF bias power may be continuously generated and provided to the processing chamber 100.

[0055] In one or more embodiments, where dual-frequency biasing is performed at operation 250, a first bias power includes a low frequency radio frequency (LFRF), such as about 350 kHz or 2MHz, and a second bias power includes a high frequency radio frequency (HFRF), such as about 13 MHz or 27 MHz. In one or more embodiments, the HFRF bias power is applied continuously, while the LFRF bias power is pulsed at the parameters described above. In certain embodiments, both the HFRF bias power and the LFRF bias power are applied continuously. In still further embodiments, only a continuous LFRF bias power is applied to the processing chamber 100, without application of an HFRF bias power (e.g., single frequency biasing).

[0056] In one or more embodiments, LFRF biasing can be utilized during the hydrogen plasma passivation process at operation 250 to create an amount of directionality for movement of generated plasma species toward the chamber seasoning layer 350. Thus, the plasma effluents can be directed toward surfaces normal to the direction of travel.

[0057] In one or more embodiments, operation 250 may be performed at a temperature below or about 100 °C, or at a temperature less than or about 80°C, or less than or about 60 °C, or less than or about 40 °C, or less than or about 30 °C, or less than or about 20 °C, or lower. Pressure within the chamber may be kept relatively low, such as at a chamber pressure of less than or about 40 Torr, or less than or about 30 Torr, or less than or about 20 Torr, and pressure may be maintained at less than or about 15 Torr, or less than or about 10 Torr, or less than or about 5 Torr, or less than or about 3 Torr, or less than or about 2 Torr, or less than or about 1 Torr, or less than or about 0.1 Torr, or less.

[0058] In one or more embodiments, the hydrogen plasma passivation treatment at operation 250 is carried out for a period of about 5 seconds or more, or about 10 seconds or more, about 15 seconds or more, about 20 seconds or more, about 25 seconds or more, about 30 seconds or more, or more.

[0059] Referring to FIG. 3D, at operation 260, a substrate 320 is positioned in the processing volume 310. The substrate 320 can be positioned on the surface 105 of the substrate support 104.

[0060] Referring to FIG. 3D, at operation 270, a film deposition process is performed. The film deposition film includes depositing a film 395 on or over the substrate 320. The film can be a silicon-containing dielectric film. Suitable silicon-containing dielectric films include but are not limited to silicon oxide, silicon nitride, and silicon oxynitride. The film deposition process can be a PECVD process.

[0061] The hydrogen plasma passivation process of operation 250 can be performed periodically to refresh the chamber seasoning layer 350, for example, after a targeted number of substrates are processed in the processing region.

[0062] Not to be bound by theory, but it is believed that the hydrogen plasma treatment described herein is effective at passivating dangling bonds and inducing ion bombardment to block fluorine diffusion pathways.44025601 wool

[0063] Not to be bound by theory but it is believed that fluorine diffusion is most active before the plasma is turned on and after the plasma is turned off due to the lack of passivation of dangling bonds and that fluorine diffusion is least active hydrogen plasma is on as silicon dangling bonds are actively passivated in the presence of the hydrogen plasma. Furthermore, the diffusion coefficient is inversely proportional to pressure, for example, lower pressure increases fluorine diffusion flux. Fluorine diffusion is most active at lower pressure during the start and end of the recipe when there is no hydrogen plasma. Fluorine diffusion is least active at higher pressure and in the presence of hydrogen plasma. In addition, after ion bombardment from LFRF power hydrogen plasma decreases the distance between Si-N / Si-0 atoms and increases the concentration of interstitial hydrogen. In one or more embodiments, the hydrogen plasma treatment shows reduction in fluorine content when SiO and / or SiN seasoning layers are present, suggesting that fluorine diffusion is modulated by interaction with silicon-containing material.

[0064] The previously described embodiments of the present disclosure have many advantages. The method minimizes fluorine diffusion from aluminum fluoride (AIF3) formed on chamber parts into the silicon nitride film, improving film purity and device performance. By preventing and / or reducing fluorine-related defects (such as particles and flakes), the process helps maintain high wafer yield and consistent device quality. Reduces the need for frequent chamber maintenance and cleaning, allowing for sequential processing of multiple substrates at elevated temperatures without downtime. Lower fluorine contamination in the deposited films leads to better electrical characteristics in subsequent chip manufacturing steps. Hydrogen plasma treatment passivates silicon dangling bonds in the seasoning layer, blocking fluorine diffusion pathways and further protecting the substrate. The process can use inductively coupled plasma (ICP), capacitively coupled plasma (CCP), or remote plasma sources, making it adaptable to various chamber designs and manufacturing setups. Utilizes a silicon oxide / silicon nitride bi-layer seasoning film, which acts as a barrier to fluorine diffusion and can be refreshed periodically for ongoing protection. Advanced chamber and plasma control (e.g., RF biasing, dual-frequency biasing) enables precise tuning of plasmaconditions, improving deposition uniformity and reproducibility. The method is compatible with existing PECVD chambers and can be implemented without major hardware changes. However, the present disclosure does not necessitate that all the advantageous features and the advantages need to be incorporated into every embodiment of the present disclosure.

[0065] In the Summary and in the Detailed Description, and the Claims, and in the accompanying drawings, reference is made to particular features (including method operations) of the present disclosure. It is to be understood that the disclosure in the specification includes all possible combinations of such particular features. For example, where a particular feature is disclosed in the context of a particular aspect, embodiment, embodiment, or example of the present disclosure, or a particular claim, that feature can also be used, to the extent possible in combination with and / or in the context of other particular aspects and embodiments of the present disclosure, and in the present disclosure generally.

[0066] Embodiments and all of the functional operations described in the specification can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structural means disclosed in the specification and structural equivalents thereof, or in combinations of them. Embodiments described herein can be implemented as one or more non-transitory computer program products, i.e., one or more computer programs tangibly embodied in a machine readable storage device, for execution by, or to control the operation of, data processing apparatus, e.g., a programmable processor, a computer, or multiple processors or computers.

[0067] The processes and logic flows described in the specification can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

[0068] The term "data processing apparatus" encompasses all apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, or multiple processors or computers. The apparatus can include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them. Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer.

[0069] Computer readable media suitable for storing computer program instructions and data include all forms of nonvolatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and CD ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

[0070] The term “comprises,” and grammatical equivalents thereof are used herein to mean that other components, ingredients, operations, are optionally present. For example, an article “comprising” (or “which comprises”) components A, B, and C can consist of (i.e., contain only) components A, B, and C, or can contain not only components A, B, and C but also one or more other components. In addition, whenever a composition, an element or a group of elements is preceded with the transitional phrase “comprising” or grammatical equivalents thereof, it is understood that it is contemplated that the same composition or group of elements may be preceded with transitional phrases “consisting essentially of,” “consisting of,” “selected from the group of consisting of,” or “is” preceding the recitation of the composition, element, or elements and vice versa.

[0071] Where reference is made herein to a method comprising two or more defined operations, the defined operations can be carried out in any order or simultaneously (except where the context excludes that possibility), and themethod can include one or more other operations which are carried out before any of the defined operations, between two of the defined operations, or after all of the defined operations (except where the context excludes that possibility).

[0072] When introducing elements of the present disclosure or exemplary aspects or embodiment(s) thereof, the articles “a,” “an,” “the” and “said” are intended to mean that there are one or more of the elements.

[0073] The terms “comprising,” “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0074] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

What is claimed is:

1. A method of controlling fluorine diffusion during a plasma enhanced chemical vapor deposition (PECVD) deposition process, comprising:exposing a chamber seasoning layer formed over one or more interior surfaces of a processing chamber to a hydrogen plasma treatment.

2. The method of claim 1 , further comprising:performing a chamber cleaning process in the processing chamber using a cleaning gas comprising fluorine prior to exposing the chamber seasoning layer.

3. The method of claim 2, wherein the chamber cleaning process forms an aluminum fluoride layer on the one or more interior surfaces.

4. The method of claim 2 further comprising:forming the chamber seasoning layer over the one or more interior surfaces after the chamber cleaning process and prior to exposing the chamber seasoning layer to the hydrogen plasma treatment.

5. The method of claim 1 , wherein the chamber seasoning layer is a sil iconcontaining seasoning layer and the one or more interior surfaces comprise an aluminum chamber component.

6. The method of claim 1 , wherein the chamber seasoning layer comprises a first chamber seasoning layer formed adjacent to the one or more interior surfaces of the processing chamber and a second chamber seasoning layer formed on the first chamber seasoning layer.

7. The method of claim 6, wherein the first chamber seasoning layer is a silicon oxide and the second chamber seasoning layer is a silicon nitride.44025601 wool8. The method of claim 1, wherein the hydrogen plasma treatment comprises generating a hydrogen plasma from a process gas comprising hydrogen and an inert.

9. A method for reducing fluorine-induced defects in a plasma enhanced chemical vapor deposition (PECVD) process, comprising:depositing a silicon-containing seasoning layer over an aluminum fluoride layer formed on an interior surface of a processing chamber; and treating the seasoning layer with a hydrogen plasma to passivate silicon dangling bonds.

10. The method of claim 9, wherein the silicon-containing seasoning layer comprises a bi-layer structure including a silicon oxide layer and a silicon nitride layer.

11. The method of claim 9, wherein the seasoning layer is deposited by a PECVD process at a temperature between about 200°C and about 400°C.

12. The method of claim 10, wherein the hydrogen plasma passivates silicon dangling bonds at an interface between the silicon oxide layer and the silicon nitride layer.

13. The method of claim 9, wherein the aluminum fluoride layer is formed by exposing the interior surface to a fluorine-containing cleaning gas selected from NF3, CF4, and C2F6.

14. The method of claim 9, wherein treating the seasoning layer with a hydrogen plasma is performed periodically to refresh the seasoning layer after a predetermined number of substrates are processed.

15. The method of claim 9, wherein the seasoning layer has a thickness between about 2 micrometers and about 20 micrometers.44025601 wool16. A method for reducing fluorine-induced defects in a plasma enhanced chemical vapor deposition (PECVD) process, comprising:exposing a chamber seasoning layer formed over one or more interior surfaces of a processing chamber to a hydrogen plasma treatment;positioning a substrate in a processing volume defined by the processing chamber subsequent to the hydrogen plasma treatment; anddepositing a silicon nitride film on the substrate within the processing volume, wherein the hydrogen plasma treatment reduces fluorine incorporation into the subsequently deposited silicon nitride film.

17. The method of claim 16, wherein the chamber seasoning layer comprises a silicon oxide layer formed adjacent to the one or more interior surfaces and a silicon nitride layer formed on the silicon oxide layer.

18. The method of claim 17, further comprising an aluminum fluoride layer formed between the one or more interior surfaces and the silicon oxide layer.

19. The method of claim 18, wherein the hydrogen plasma treatment passivates silicon dangling bonds at an interface between the silicon oxide layer and the silicon nitride layer.

20. The method of claim 19, wherein the aluminum fluoride layer is formed by exposing the one or more interior surfaces to a fluorine-containing cleaning gas selected from NF3, CF4, and C2F6.

Images