Modifying the hydrophobicity of wafer surfaces using organosilicon precursors

Abstract

Provided herein are methods and apparatus for modifying a wafer surface using an organosilicon precursor. After a dielectric material is deposited by an atomic layer deposition (ALD) process, an organosilicon precursor is applied to the wafer surface. In some implementations, the dielectric layer is made of silicon oxide. The application of an organosilicon precursor to the wafer surface can be performed in the same chamber as the ALD process. The organosilicon precursor can modify the wafer surface to increase its hydrophobicity, thereby improving the adhesion of the photoresist on the wafer surface. In some implementations, after the organosilicon precursor is applied to the wafer surface, the wafer surface can be exposed to an inert gas RF plasma.

Description

[0001] Incorporated by Reference

[0002] The PCT application form is filed concurrently with this specification as a part of this application. Each application to which this application claims the benefit or priority as identified in the concurrently filed PCT application form is incorporated herein by reference in its entirety and for all purposes. Background Art

[0003] Patterning structures using photolithography continues to become increasingly important in semiconductor manufacturing and advanced integrated circuit (IC) technology. A photoresist mask is patterned during the photolithography process, but the photoresist mask may collapse or peel off, depending on the adhesion between the photoresist mask and the underlying material. Processing methods have been and are being developed to promote adhesion between the photoresist mask and the underlying material. Summary of the invention

[0004] A method for increasing the hydrophobicity of a wafer surface is provided, wherein the method comprises: depositing a silicon-containing layer on a wafer by atomic layer deposition (ALD); and introducing a certain amount of a gas-phase organosilicon precursor onto the wafer surface to increase the hydrophobicity of the wafer surface.

[0005] In some implementations, the method further comprises: exposing the wafer to an RF plasma after introducing the dose of the organosilicon precursor. The RF plasma may comprise an inert gas plasma. The RF power applied to the RF plasma may be between about 100 W and about 1000 W. In some implementations, depositing the silicon-containing layer by ALD comprises: introducing a dose of a silicon-containing precursor onto the wafer surface; and converting the silicon-containing precursor to form an adsorption-limited amount of the silicon-containing layer. In some implementations, depositing the silicon-containing layer by ALD and introducing the dose of the organosilicon precursor occurs in an ALD chamber without introducing a vacuum break. In some implementations, the method further comprises depositing a photoresist on the surface of the silicon-containing layer after introducing the dose of the organosilicon precursor. In some implementations, the contact angle measurement on the wafer surface after introducing the dose of the organosilicon precursor is equal to or greater than about 40°. In some embodiments, introducing the dose of the organosilicon precursor comprises adsorbing the organosilicon precursor on the wafer surface without converting the organosilicon precursor during an atomic layer deposition cycle. In some implementations, the organosilicon precursor comprises an aminosilane.

[0006] Another aspect relates to an apparatus for increasing the hydrophobicity of a wafer surface. The apparatus includes: a processing chamber including a wafer support for supporting a wafer; and a controller including instructions for: (a) depositing a silicon-containing layer on the wafer by atomic layer deposition (ALD) in the processing chamber; and (b) introducing a dose of a vapor phase organosilicon precursor to the wafer surface in the processing chamber to increase the hydrophobicity of the wafer surface.

[0007] In some implementations, the silicon-containing layer comprises silicon nitride, silicon carbide, silicon oxide, or a combination thereof, and wherein introducing the dose of the organosilicon precursor comprises adsorbing the organosilicon precursor on the surface of the wafer in an atomic layer deposition cycle without converting the organosilicon precursor. In some implementations, the controller further comprises instructions for: (c) exposing the wafer to an inert gas RF plasma. In some implementations, the controller further comprises instructions for: (d) transferring the wafer from the processing chamber to a deposition chamber configured to deposit a photoresist on the silicon-containing layer.

[0008] These and other aspects are further described below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic diagram of an exemplary wafer having a treated surface layer and a patterned photoresist mask on the treated surface layer according to some implementations.

[0010] Figure 2 is a timing diagram showing an example of a cycle in an atomic layer deposition (ALD) process.

[0011] Figure 3 is a timing diagram showing an example of a cycle in an ALD process followed by a treatment cycle to treat a surface of an ALD deposited layer according to some implementations.

[0012] Figure 4 is a flow chart of an exemplary method for increasing the hydrophobicity of a wafer surface according to some implementations.

[0013] Figure 5 Schematic diagram showing possible bonding interactions between an aminosilane precursor and a silicon surface according to some implementations.

[0014] Fig. 6A The untreated ALD deposited silicon oxide (SiO x )Contact angle measurement of the film.

[0015] Figure 6BALD deposited SiO is shown after processing according to some implementations. x Contact angle measurements of films.

[0016] Figure 6C ALD deposited SiO is shown after processing according to some other implementations. x Contact angle measurements of films.

[0017] Fig. 7A A graph showing contact angle measurements as a function of the number of processing cycles according to some implementations is shown, where each processing cycle includes a dosing step and an RF plasma exposure step.

[0018] Figure 7B Contact angle measurements are shown as a function of chamber pressure during processing cycles, where each processing cycle includes a dosing step and an RF plasma exposure step, according to some implementations.

[0019] Figure 7C A graph showing contact angle measurements as a function of RF exposure time during a processing cycle according to some implementations is shown, where each processing cycle includes a dosing step and an RF plasma exposure step.

[0020] Figure 8 is a schematic diagram of an exemplary processing chamber for performing disclosed implementations.

[0021] Fig. 9 is a schematic diagram of an exemplary processing tool for performing disclosed implementations. DETAILED DESCRIPTION

[0022] In the present disclosure, the terms "semiconductor wafer", "wafer", "substrate", "wafer substrate", and "partially manufactured integrated circuit" are used interchangeably. It should be understood by those skilled in the art that the term "partially manufactured integrated circuit" may refer to a silicon wafer during any of the multiple stages of integrated circuit fabrication performed thereon. Wafers or substrates used in the semiconductor device industry generally have a diameter of 200 mm, or 300 mm, or 450 mm. The following detailed description assumes that the present disclosure is implemented on a wafer. However, the present disclosure is not limited thereto. The workpiece may have a variety of shapes, sizes, and materials. In addition to semiconductor wafers, other workpieces that may utilize the present disclosure include various items such as printed circuit boards.

[0023] Photoresist adhesion

[0024] The photoresist mask can be patterned to define features of the underlying layers of the wafer. In a conventional photolithography process, a photoresist material is deposited on a wafer and then exposed to light filtered by a photo grid. The photo grid is typically a glass plate that is patterned with feature geometries that block light from propagating through the photo grid. After passing through the photo grid, the light contacts the surface of the photoresist material and changes the chemical composition of the photoresist material so that a developer can remove a portion of the photoresist material. A developer is applied to the photoresist material to remove a portion of the photoresist material. The patterned photoresist material is used as a mask to etch the underlying layer.

[0025] One of the challenges in photoresist patterning is the proper adhesion between the photoresist material and the underlying material. Poor adhesion can lead to several adverse effects in pattern formation. Poor adhesion can lead to undercutting, reduced resolution, reduced product yield or may lead to the complete loss of the photoresist pattern. Specifically, poor adhesion can lead to the collapse of the photoresist pattern or the peeling of the photoresist pattern. When forming a higher photoresist pattern on a narrow substrate, this is more likely to happen. Subsequent etching and / or processing requires a high level of adhesion between the photoresist material and the underlying material.

[0026] Typically, the surface of the wafer is treated prior to deposition of the photoresist material to promote adhesion between the photoresist material and the underlying layers. For example, the use of hexamethyldisilazane (HMDS) and a vapor priming system can promote adhesion to polysilicon, metals, silicon oxide (SiO x ) layer and various other materials. Without being bound by any theory, adhesion promoters such as HMDS can deposit carbon-containing molecules on the wafer surface to modify the surface and make it more hydrophobic. Other common adhesion promoters may include trichlorophenylsilane, trichlorobenzene and xylene. Such adhesion promoters can be applied by vapor phase plating in a bath process. In some implementations, an adhesion promoter such as spin-on polydimethylsiloxane (PDMS) can be deposited as an adhesion layer before depositing the photoresist layer. The surface treatment is usually performed ex situ with the deposition chamber used to deposit the underlying layer.

[0027] Figure 11 is a schematic diagram of an exemplary wafer having a processed surface layer and a patterned photoresist mask on the processed surface layer according to some implementations. Wafer 100 includes a patterned photoresist mask 101 on a processed surface layer 102. The processed surface layer 102 is formed on a bulk layer 103, wherein an intermediate layer 104 is below the bulk layer 103, and an underlying layer 105 is below the intermediate layer 104. In some implementations, the patterned feature size of the patterned photoresist mask 101 can be equal to or less than about 120 nm, equal to or less than about 90 nm, equal to or less than about 60 nm, or equal to or less than about 50 nm.

[0028] In some implementations, the bulk layer 103 includes SiO x The treated surface layer 102 may also include a dielectric material, except that the dielectric material is modified by treatment. Examples of such treatments include modifications by silazane (e.g., HMDS), silane (trichlorophenylsilane) or siloxane (e.g., PDMS) as described above. Because the surface of the main layer 103 can be hydrophilic, one of the above treatments can modify the surface of the main layer 103 to be hydrophobic. In particular, the treated surface layer 102 formed at the interface between the patterned photoresist mask 101 and the main layer 103 is hydrophobic, thereby promoting adhesion between the patterned photoresist mask 101 and the main layer 103. The treatment does not affect the intermediate layer 104 or the bottom layer 105. In some embodiments, treating the main layer 103 to form the treated surface layer 102 may include treating the main layer 103 with a plasma to improve adhesion.

[0029] ALD Integrated Surface Treatment

[0030] The processing method disclosed herein promotes adhesion between a photoresist material and an underlying material. The processing method increases the hydrophobicity of the underlying material. The processing method is integrated with an atomic layer deposition (ALD) process or a plasma enhanced atomic layer deposition (PEALD) process when depositing the underlying material. By integrating the processing method with the ALD process, processing time can be reduced, yield can be improved, and product yield can be increased. In addition, integrating the processing method with the ALD process avoids the use of separate chambers, which would require transferring the wafer from one chamber to another, which would result in a vacuum interruption, thereby increasing the likelihood of unwanted substances coming into contact with the wafer. This may result in loss of material function and / or integrity of the wafer.

[0031] The processing method of the present disclosure can be performed in an ALD chamber or an ALD tool. ALD is a technique for depositing thin layers of material using continuous self-limiting reactions. Generally, an ALD cycle includes the following operations: delivering and adsorbing at least one reactant to the surface of a wafer, and then converting the adsorbed reactant to form a partial layer of the film. Unlike chemical vapor deposition (CVD) technology, the ALD process uses a surface self-limiting deposition reaction to deposit the film layer by layer. A typical ALD cycle may include: (i) dosing, which delivers and adsorbs precursor materials to the surface of the wafer; (ii) sweeping away excess precursor materials from the chamber and leaving a self-limiting monolayer on the surface of the wafer, (iii) delivering reactant materials to react with the adsorbed precursor materials, and (iv) sweeping away unreacted reactant materials or reaction byproducts from the chamber. The dosing step can adsorb the precursor material in a self-limiting manner, so that once the active sites are occupied by the precursor material, little or no additional precursor material will be adsorbed on the surface of the wafer. The reactant material can also react with the precursor material in a self-limiting or adsorption-limited manner. A sweep step may optionally be performed to remove excess precursor material, reaction byproducts, and / or unreacted reactant material from the chamber to complete the ALD cycle.

[0032] Figure 2 is a timing diagram illustrating an example of a cycle in an ALD process. Figure 2 Stages of a typical ALD process 200 are shown for various process parameters, such as plasma, precursor flow, reactant flow, and carrier gas flow. Figure 2 Each of the ALD cycles in can represent a PEALD cycle. The lines represent when flows are turned on and off, or when the plasma is turned on and off. Exemplary process parameters include, but are not limited to, flow rates of precursor and reactant species, flow rates of carrier gas species, plasma power and frequency, wafer temperature, and process chamber pressure. In some embodiments, Figure 2 The example in this paper is used to deposit SiO using a silicon-containing precursor and oxygen plasma. x The film, wherein the reactant species is an oxygen-containing reactant, which is used to convert the adsorbed precursor layer to form SiO on the wafer x membrane.

[0033] Any suitable number of deposition cycles may be included in the ALD process to deposit a dielectric film of a desired thickness. Figure 2The timing in describes two deposition cycles 210A and 210B. Each deposition cycle 210A, 210B includes various stages. For example, during deposition cycle 210A, the wafer is exposed to the precursor during the batching stage 257A, and during deposition cycle 210B, the wafer is exposed to the precursor during the cycle stage 257B. In some implementations, the precursor is a silicon-containing precursor. The precursor is a single reagent or a reagent mixture used to make a dielectric film, wherein the reagent or reagent mixture used to deposit the silicon-containing film contains at least one silicon compound. In some implementations, the silicon-containing precursor can be, for example, a silane, a halosilane, or an aminosilane. Examples of silanes are silane (SiH 4 ), disilane (Si 2 H 6 ), and organosilanes, such as methylsilane, ethylsilane, isopropylsilane, tert-butylsilane, dimethylsilane, diethylsilane, di-tert-butylsilane, allylsilane, sec-butylsilane, tert-hexylsilane, isopentylsilane, tert-butyldisilane, di-tert-butyldisilane, etc. Examples of halosilanes are iodosilane, bromosilane, chlorosilane, and fluorosilane. Specific chlorosilanes are tetrachlorosilane, trichlorosilane, dichlorosilane, monochlorosilane, chloroallylsilane, chloromethylsilane, dichloromethylsilane, chlorodimethylsilane, chloroethylsilane, tert-butylchlorosilane, di-tert-butylchlorosilane, chloroisopropylsilane, chlorosec-butylsilane, tert-butyldimethylchlorosilane, tert-hexyldimethylchlorosilane, etc. Examples of aminosilanes are mono-, di-, tri- and tetraaminosilanes (H, 3 Si(NH 2 ),H 2 Si(NH 2 ) 2 ,HSi(NH 2 ) 3 and Si(NH 2 ) 4 ), and substituted mono-, di-, tri- and tetraaminosilanes, such as tert-butylaminosilane, methylaminosilane, tert-butylsilylamine, bis(tert-butylamino)silane (SiH 2 (NHC(CH 3 ) 3 ) 2 (BTBAS)), tert-butylsilylcarbamate, SiH(CH 3 )-(N(CH 3 ) 2 ) 2 、SiHCl-(N(CH 3 ) 2 ) 2 、(Si(CH 3 ) 2 NH) 3etc. Further examples of aminosilanes are trisilylamine (N(SiH 3 )). During the dosing phases 257A and 257B, the plasma is turned off and no reactant species flow to the wafer. In some implementations, the wafer is exposed to the precursor for a time between about 0.1 seconds and about 60 seconds, or between about 0.2 seconds and about 6 seconds, depending on the flow rate and the wafer surface area. In some implementations, a carrier gas or inert gas flows during the dosing phases 257A and 257B.

[0034] In some implementations, the precursor is adsorbed onto the wafer surface in a self-limiting manner such that once the active sites are occupied by the precursor, little or no additional precursor will be adsorbed onto the wafer surface. For example, the precursor material may be adsorbed onto at least 60% of the wafer surface. Thus, the precursor material may be fully or partially saturated on the wafer surface. Molecules of the precursor are adsorbed onto the wafer surface, including chemically adsorbed species and / or physically adsorbed molecules of the precursor. During dosing stages 257A and 257B, the precursor material is adsorbed onto the wafer surface by one or both of chemical adsorption and physical adsorption. In most cases, the precursor material is adsorbed by chemical adsorption and physical adsorption. When the precursor is adsorbed onto the active sites on the wafer surface, a thin layer of the precursor material is formed on the surface. In various implementations, the layer may be less than a monolayer and may have a thickness between about 0.1 angstroms. Unlike CVD or CVD-like processes, the precursor does not decompose to form a thin film of dielectric material.

[0035] In the sweep phases 259A and 259B of the deposition cycles 210A and 210B, respectively, the process chamber is optionally purged to remove excess precursor material in the gas phase that is not adsorbed onto the wafer surface. The sweep may involve a sweep gas, which may be a carrier gas used in other operations or may be a different gas. In some implementations, the sweep may involve evacuating the process chamber. During the sweep phases 259A and 259B, the precursor flow is turned off and no plasma is ignited. During the sweep phases 259A and 259B, reactant materials such as oxygen-containing reactants may or may not be provided to the process chamber. In some implementations, the carrier gas may continue to flow to purge any excess precursor material from the process chamber. In some implementations, the sweep phases 259A and 259B may each include one or more extraction sub-phases for extracting the process chamber. Alternatively, it should be understood that in some implementations, each sweep phase 259A and 259B may be omitted. Each sweeping stage 259A and 259B may have any suitable duration, such as between about 0 seconds and about 60 seconds, or about 0.01 seconds. In some implementations, increasing the flow rate of one or more sweeping gases can reduce the duration of each sweeping stage 259A and 259B. For example, the sweeping gas flow rate can be adjusted to various reactant thermodynamic properties and / or geometric properties of the processing chamber and / or the processing chamber pipeline to change the duration of each sweeping stage 259A and 259B. In a non-limiting example, the duration of the sweeping stage can be adjusted by modulating the sweeping gas flow rate. This can reduce the deposition cycle time, thereby increasing the wafer yield. After sweeping, at least some of the precursor materials remain adsorbed on the wafer surface. At least some of the precursor materials remain adsorbed on the wafer surface by chemical adsorption and physical adsorption.

[0036] Plasma can be ignited during the plasma exposure phases 261A and 261B of the deposition cycles 210A and 210B, respectively. For example, the wafer can be exposed to oxygen plasma during the plasma exposure phases 261A and 261B. It should be understood that the "oxygen plasma" mentioned includes the plasma of any oxygen-containing reactant, and is not limited to the plasma of pure oxygen. Alternatively, the wafer can be exposed to nitrogen plasma during the plasma exposure phases 261A and 261B, wherein the "nitrogen plasma" mentioned includes the plasma of any nitrogen-containing reactant (e.g., ammonia), and is not limited to the plasma of pure nitrogen. It should be understood that plasma is not limited to oxygen plasma or nitrogen plasma, but can include the plasma of any suitable reactant material. During the plasma exposure phases 261A and 261B, the flow and plasma of the reactant material are all turned on. In some implementations, the flow of the reactant material can be turned on before the plasma is turned on. The flow of the precursor is turned off during the plasma exposure phases 261A and 261B. In some implementations, the carrier gas can continue to flow during the plasma exposure phases 261A and 261B. The wafer may be exposed to the plasma of the reactant species for a duration between about 0.1 seconds and about 60 seconds, or between about 0.2 seconds and about 6 seconds. In some implementations, the duration of the plasma exposure phases 261A and 261B may exceed the time for the plasma to interact with all the precursors adsorbed on the wafer surface, thereby forming a continuous film on the wafer surface.

[0037] Exemplary oxygen-containing reactants or oxidants include oxygen, water, carbon dioxide, carbon monoxide, nitrous oxide, nitric oxide, sulfur oxide, sulfur dioxide, oxygen-containing hydrocarbons, ozone, and combinations thereof. In some implementations, the wafer is simultaneously exposed to the oxygen-containing reactant and the carrier gas while the plasma is ignited. For example, oxygen is introduced to the wafer along with helium, argon, or a mixture thereof while the plasma is ignited.

[0038] Plasma energy is provided to activate the reactant species into ions, free radicals, and other activated species that react with the adsorbed precursor layer. For example, the plasma may directly or indirectly activate gas phase molecules of the reactant species to form free radicals or ions. Once the reactant species is activated to form a plasma, the free radicals and / or ions of the reactant species convert the adsorbed precursor into a dielectric film (e.g., SiO) on the wafer surface. x ).

[0039] In some implementations, the plasma is an in-situ plasma such that the plasma is formed directly above the wafer surface in the processing chamber. The in-situ plasma may be at a power of between about 0.2 W / cm 2 and about 2.1 W / cm 2The power / wafer area between is ignited. For example, the power can be in the range of about 100 watts to about 10,000 watts, or in the range of about 150 watts to about 6,000 watts, or in the range of about 600 watts to about 4000 watts. For example, a plasma for an ALD process can be generated by applying an RF field to a gas using a capacitively coupled plate or a remote plasma source. In the case of a capacitively coupled plasma, the plasma is ignited by ionizing the gas between the plates by an RF field, thereby generating free electrons in the plasma discharge region. These electrons are accelerated by the RF field and may collide with gas phase reactant molecules. The collision of these electrons with reactant molecules may form free radical species that participate in deposition and conversion processes. It should be understood that the RF field can be coupled via any suitable electrode. In a variety of implementations, a high frequency plasma having a frequency of at least about 13.56 MHz, or at least about 27 MHz, or at least about 40 MHz, or at least about 60 MHz is used. In some implementations, a microwave-based plasma can be used. Non-limiting examples of electrodes include a process gas distribution nozzle and a wafer support base. It should be understood that the plasma used in the ALD process may be formed by one or more suitable methods other than capacitive coupling of the RF field to the gas. In some implementations, the plasma is a remote plasma such that the reactant species are ignited in a remote plasma generator located upstream of the process chamber and then transported to the process chamber containing the wafer. In some implementations, other types of plasma may be used, such as inductively coupled plasma rather than capacitively coupled plasma.

[0040] although Figure 2 The timing diagram in FIG. 2 shows plasma exposure phases 261A and 261B for converting adsorbed precursor materials, but it should be understood that thermal conversion phases may replace plasma exposure phases 261A and 261B. During the thermal conversion phase, the wafer surface is exposed to the reactant species at an elevated temperature. The elevated temperature may be applied to the wafer via a wafer support or pedestal. In some implementations, the elevated temperature may be equal to or greater than about 400° C. At the elevated temperature, the reactant species may undergo a dissociation reaction, and the dissociated species may react with the adsorbed precursor to convert the adsorbed precursor into a dielectric film (e.g., SiO x ). The heat at high temperature can thermodynamically drive the adsorbed reactants to undergo surface chemical reactions, thereby forming a stable film. In some implementations, the reactant species in the thermal conversion stage can include oxygen-containing reactants or nitrogen-containing reactants.

[0041] In the sweeping phases 263A and 263B of deposition cycles 210A and 210B, respectively, the processing chamber is optionally swept to remove reaction byproducts and / or unreacted reactant materials from the processing chamber. During the sweeping phases 263A and 263B, the plasma is extinguished or the elevated temperature is turned off. The precursor flow is turned off, and the plasma is not ignited. During the sweeping phases 263A and 263B, the reactant material may or may not be supplied to the processing chamber. In some implementations, the sweeping may be performed by flowing a carrier gas or any other inert gas.

[0042] Performing operations 257A, 259A, 261A, and 263A may constitute an ALD cycle, such as deposition cycle 210A. If the thickness of the deposited dielectric film is insufficient or undesirable, the ALD cycle may be repeated as shown in deposition cycle 210B. The ALD cycle may be repeated until a dielectric film of sufficient or desired thickness is formed.

[0043] Figure 3 is a timing diagram illustrating an example of a cycle of an ALD process and a subsequent processing cycle for treating a surface of an ALD deposited layer, according to some implementations. Figure 3 The stages for various process parameters (such as plasma, precursor flow, reactant flow, and carrier gas flow) in the ALD process 300 are shown. The lines indicate when the flows are turned on and off, or when the plasma is turned on and off. Exemplary process parameters include, but are not limited to, the flow rates of precursor and reactant species, the flow rates of carrier gas species, plasma power and frequency, wafer temperature, and process chamber pressure. In some embodiments, Figure 3 An example of this is the use of a silicon-containing precursor and oxygen plasma to deposit SiO x The film, wherein the reactant species is an oxygen-containing reactant, which is used to convert the adsorbed precursor material to form SiO on the wafer x membrane.

[0044] Similar to Figure 2 The timing diagram in Figure 3 The timing diagram in FIG. 1 includes a dosing phase 357A, an optional sweep phase 359A, a plasma exposure phase 361A, and an optional sweep phase 363A, which may constitute an ALD cycle. For example, a deposition cycle 310A. Each of operations 357A, 359A, 361A, and 363A may be associated with Figure 2 Operations 257A, 259A, 261A, and 263A described in 361A are the same or similar. In some implementations, a thermal conversion phase can replace the plasma exposure phase 361A to convert the adsorbed precursor material on the wafer surface. If the thickness of the deposited dielectric film is insufficient or undesirable, the ALD cycle can be repeated until a sufficient thickness or a desired thickness is achieved.

[0045] and Figure 2 The timing diagram in is different. Figure 3 The timing diagram in is that the processing cycle 310B is after the deposition cycle 310A. The processing cycle 310B includes a dosage stage 357B after the deposition cycle 310A. In some implementations, the dosage stage 357B is followed by an optional sweep stage 359B. The processing cycle 310B mimics one or more stages of an ALD cycle and essentially constitutes a partial ALD cycle. The processing cycle 310B can be performed in the same ALD chamber or tool as the deposition cycle 310A used to deposit the dielectric film, so that no vacuum break is introduced between the deposition and processing operations. Therefore, the processing cycle 310B is part of the ALD process 300 and can be referred to as an ALD integrated surface treatment.

[0046] During the processing cycle 310B, the wafer is exposed to an organosilicon precursor during a dosing phase 357B. An organosilicon precursor is a single reagent or a mixture of reagents used to process dielectric films deposited by ALD. The organosilicon precursor may include one or more silicon atoms and at least one hydrocarbon backbone. In some implementations, the organosilicon precursor includes an alkylsilane. In some implementations, the organosilicon precursor includes an aminosilane. Examples of aminosilanes are butylaminosilane, methylaminosilane, diethylaminosilane, tert-butylsilylamine, bis-tert-butylaminosilane, bis-diethylaminosilane, and the like. During the dosing phase 357B, the plasma is turned off and no reactant species flow to the wafer. In some implementations, the wafer is exposed to the precursor for a time between about 0.1 seconds and about 60 seconds, or between about 0.2 seconds and about 6 seconds, depending on the flow rate and the surface area of ​​the wafer. In some implementations, a carrier gas or an inert gas flows during the dosing phase 357B.

[0047] The organosilicon precursor adsorbed on the wafer surface starting from the dosage stage 357B modifies the wafer surface to increase its hydrophobicity. Without being bound by any theory, the adsorbed organosilicon precursor can increase the carbon content on the wafer surface to increase its hydrophobicity, thereby providing improved adhesion between the subsequently deposited photoresist material and the ALD deposited dielectric film.

[0048] In some implementations, the organosilicon precursor is adsorbed on the wafer surface in a self-limiting manner such that once the active sites are occupied by the organosilicon precursor, little or no additional organosilicon precursor will be adsorbed on the wafer surface. For example, the organosilicon precursor material can be adsorbed on at least 60% of the wafer surface. As the organosilicon precursor adsorbs onto the active sites on the wafer surface, a thin layer of the organosilicon precursor material forms on the surface. In various implementations, the layer can be less than a monolayer and can have a thickness between about 0.1 angstroms and about 0.1 angstroms. The thickness of the thin layer of organosilicon precursor material may be between about 100 angstroms and about 100 angstroms, or between about 0.5 angstroms and about 20 angstroms, or between about 0.9 angstroms and about 6 angstroms. The thickness of the thin layer of organosilicon precursor material may be no greater than the hydrodynamic radius of the organosilicon precursor molecule, or equivalent to the thickness of a monolayer of organosilicon precursor molecules adsorbed on the surface. Unlike CVD or CVD-like processes, the organosilicon precursor does not decompose to form a thin film of dielectric material. Moreover, unlike the ALD process, the organosilicon precursor is not converted to form a thin film of dielectric material.

[0049] In some implementations, a sweep phase 359B may follow the dosing phase 357B to optionally sweep excess organosilicon precursor that is not adsorbed in the gas phase on the wafer surface. The sweep may involve a sweep gas, which may be a carrier gas used in other operations or may be a different gas. In some implementations, the sweep may involve pumping the process chamber. During the sweep phase 359B, the precursor flow is turned off and no plasma is ignited. In some implementations, the carrier gas may continue to flow to sweep any excess precursor material from the process chamber. In some implementations, the sweep phase 359B may include one or more pumping sub-phases for pumping the process chamber. Alternatively, it should be understood that in some implementations, the sweep phase 359B may be omitted. The sweep phase 359B may have a suitable duration, such as between about 0 seconds and about 60 seconds or about 0.01 seconds. After the sweep, at least some organosilicon precursor material remains adsorbed on the wafer surface. Specifically, at least some of the organosilicon precursor material remains adsorbed on the wafer surface by chemical adsorption and physical adsorption.

[0050] The ALD process 300 for depositing and treating ALD deposited dielectric films terminates with a treatment cycle 310B. The adsorbed organosilicon precursor from the batching stage 357B is subsequently converted without any reactants by plasma conversion, thermal conversion, or other techniques for converting adsorbed organosilicon precursors. The adsorbed organosilicon precursor modifies the wafer surface to increase its hydrophobicity. In some embodiments, a plasma exposure operation is optionally performed after the batching stage 357B or the sweep stage 359B, which does not convert the adsorbed organosilicon precursor. The wafer may be exposed to a low power inert gas plasma to adjust or otherwise adjust the hydrophobicity of the wafer surface. The aforementioned plasma exposure operation may be performed in the same ALD chamber or tool as the deposition cycle 310A and the treatment cycle 310B, so that a vacuum break is not introduced from the plasma exposure operation.

[0051] Figure 4 is a flow chart of an exemplary method for increasing the hydrophobicity of a wafer surface according to some implementations. The operations in process 400 may be performed in a different order and / or with different, fewer, or additional operations.

[0052] At frame 410 of process 400, a dose of silicon-containing precursor is introduced onto the wafer surface. The exemplary chemical properties of silicon-containing precursors are described above. The silicon-containing precursor is delivered to the wafer surface in a self-limiting manner to be adsorbed on the wafer surface. As described above, introducing a dose of silicon-containing precursor can be part of the ALD cycle. In some implementations, the silicon-containing precursor can be delivered at a flow rate between about 20sccm and about 5000sccm or between about 1000sccm and about 4000sccm. In some implementations, the duration of exposing the wafer to the silicon-containing precursor is between about 0.1 seconds and about 60 seconds, or between about 0.2 seconds and about 6 seconds. In the process of introducing a dose of silicon-containing precursor, the plasma is turned off, and there is no reactant material for converting the silicon-containing precursor to flow onto the wafer.

[0053] At frame 420 of process 400, the silicon-containing precursor is converted to form a silicon-containing layer with a limited amount of adsorption. In some implementations, the silicon-containing layer includes silicon nitride, silicon carbide, silicon oxide, or a combination thereof. During the conversion process, the reactant material may flow onto the wafer. The silicon-containing precursor adsorbed on the surface of the wafer can be converted to form a silicon-containing layer by reacting with the reactant material. In some implementations, the reactant material includes an oxygen-containing reactant, such as oxygen or ozone. In some implementations, the reactant material includes a nitrogen-containing reactant such as nitrogen or ammonia. In some implementations, the silicon-containing precursor is converted by plasma exposure when the plasma is ignited. In some implementations, the silicon-containing precursor is converted by thermal conversion via high temperature.

[0054] Dosing the silicon-containing precursor to the wafer at block 410 and converting the silicon-containing precursor at block 420 can be performed in the same process chamber without introducing a vacuum break between operations. The dosing operation at block 410 and the converting operation at block 420 can be repeated until a silicon-containing layer of a desired thickness is formed. Performing the dosing operation at block 410 and the converting operation at block 420 can constitute depositing a silicon-containing layer on a wafer by an ALD process or ALD cycle.

[0055] An optional purge operation may be performed between the dosing operation of block 410 and the converting operation of block 420. The purge operation may purge a purge gas to remove excess silicon-containing precursor in the gas phase from the process chamber.

[0056] In some implementations, the wafer surface includes a hydrophobic layer on the silicon-containing layer. Surface treatment of the silicon-containing layer can be performed before introducing a dose of the organosilicon precursor. For example, the silicon-containing layer can be treated with HMDS, PDMS, or other adhesion promoters to form a hydrophobic layer or at least modify the surface of the silicon-containing layer. In some implementations, process 400 also includes depositing a hydrophobic layer on the silicon-containing layer before introducing a dose of the organosilicon precursor. Thus, introducing the organosilicon precursor in combination with the hydrophobic layer can further increase the hydrophobicity of the wafer surface. An example of a hydrophobic layer is Figure 1 Treated surface layer 102 is shown. The hydrophobic layer may be a hydrosilazane treated surface prior to introduction of the organosilicon precursor.

[0057] At block 430 of process 400, a dose of an organosilicon precursor is introduced in a vapor phase onto the wafer surface to increase the hydrophobicity of the wafer surface. In some implementations, the organosilicon precursor may be different from the silicon-containing precursor introduced at block 410. In some implementations, the organosilicon precursor includes an alkylsilane. In some implementations, the organosilicon precursor includes an aminosilane.

[0058] Figure 5 Schematic diagram showing possible bonding interactions between an aminosilane precursor and a silicon surface according to some implementations. Figure 5 As shown, the silicon surface may include a silicon oxide surface. The silicon oxide surface includes hydroxyl end groups, which may be removed by ambient air (H 2 O and O 2 ) or mild etchants (such as H 2 Hydrofluoric acid (HF) in O is formed. The hydroxyl end groups on the silicon oxide surface may be susceptible to reaction with the organosilicon precursor. Figure 5In the reaction, the Si-OH bonds from the silicon oxide surface may interact with the bis-diethylaminosilane precursor. Without being limited by any theory about how the bis-diethylaminosilane precursor interacts with the silicon oxide surface, the diethylamine group may be broken off from the bis-diethylaminosilane precursor, leaving the diethylaminosilane group. The Si-NR bonds in the diethylaminosilane group may attach to the Si-O bonds from the silicon oxide surface. This reaction mechanism is discussed in Baek, Seung-Bin, Dae-Hee Kim, and Yeong-Cheol Kim, "Adsorption and surface reaction of bis-diethylaminosilane as a Si precursor on an OH-terminated Si(001)surface," Applied Surface Science (2012), pgs. 6341-6344; the entire text of which is incorporated by reference for all purposes. Furthermore, without being bound by any theory as to why the bis-diethylaminosilane precursor results in increased hydrophobicity, the diethylaminosilane groups terminated on the silicon oxide surface may provide a high wetting angle with water, thereby providing a relatively high hydrophobicity to the surface.

[0059] Back to Figure 4 , introducing a dose of an organosilicon precursor is performed in the same ALD chamber as depositing a silicon-containing layer by ALD, without introducing a vacuum interruption between the two operations. Specifically, the introduction of a dose of an organosilicon precursor at box 430 is performed in the same ALD chamber as the introduction of a dose of a silicon-containing precursor at box 410 and the conversion of the silicon-containing precursor at box 420. Therefore, the introduction of a dose of an organosilicon precursor is part of a surface treatment operation integrated with the ALD process for depositing a silicon-containing layer. This surface treatment operation is not performed in a chamber separate from the ALD process. In fact, the surface treatment operation corresponds to the dosing phase of the ALD cycle and can be performed by the ALD mechanism. The ALD process can end with a dosage phase involving an organosilicon precursor. In some implementations, introducing a dose of an organosilicon precursor includes adsorbing the organosilicon precursor on the wafer surface without converting the organosilicon precursor in the ALD cycle. In other words, the ALD cycle of the surface treatment operation does not include a thermal conversion or plasma conversion phase involving a reactant substance (e.g., a nitrogen-containing reactant or an oxygen-containing reactant) reacting with the organosilicon precursor.

[0060] The organosilicon precursor can be adsorbed on the surface of the silicon-containing layer to modify the surface of the silicon-containing layer and increase its hydrophobicity. In order to measure the hydrophobicity, a contact angle measurement can be performed. The contact angle of a water drop placed on the wafer surface can be measured by using a contact angle goniometer. The contact angle is the angle between the horizontal wafer surface and a tangent drawn along the curvature of the water drop at the edge of the water drop. When the water drop wets the wafer surface well and the tangent is almost flat, the contact angle can be close to zero degrees. A higher contact angle indicates a hydrophobic surface and a lower contact angle indicates a hydrophilic surface. In some implementations, the contact angle measurement of the wafer surface after the surface treatment operation is equal to or greater than 30°, equal to or greater than 35°, equal to or greater than 40°. A more hydrophobic surface can provide sufficient adhesion between the silicon-containing layer and the photoresist.

[0061] Fig. 6A The untreated ALD deposited silicon oxide (SiO x ) film contact angle measurement. x The contact angle measurement without any surface treatment is about 5°. Figure 6B ALD deposited SiO is shown after processing according to some implementations. x Contact angle measurements of ALD deposited SiO x The contact angle measurement in the case of ALD-integrated surface treatment of the aminosilane precursor on the film was about 46.2°. The ALD-integrated surface treatment was not followed by exposure to RF plasma. The ALD-integrated surface treatment dosed aminosilane to the wafer surface at a flow rate of 1250 sccm for 0.25 seconds of the precursor at a chamber pressure of 3 Torr.

[0062] Return to Figure 4 , at block 440 of process 400, a photoresist is optionally deposited on the surface of the silicon-containing layer. The surface of the silicon-containing layer is hydrophobic and provides improved adhesion of the photoresist to the silicon-containing layer. In some implementations, prior to depositing the photoresist, the process further includes transferring the wafer from the ALD chamber or tool to a deposition chamber configured to deposit the photoresist on the silicon-containing layer. The photoresist can be patterned and the silicon-containing layer can be etched without collapsing or peeling the photoresist. The improved adhesion between the photoresist and the silicon-containing layer further increases production throughput and product yield.

[0063] In some implementations, process 400 further includes exposing the wafer to an RF plasma after introducing a dose of the organosilicon precursor. The RF plasma may include an inert gas plasma, such as an argon plasma. In addition, the RF plasma is a low-power plasma, wherein the RF power applied to the RF plasma is between about 100 W and about 1000 W, or between about 100 W and about 500 W. Applying the low-power inert gas plasma minimizes the conversion of the adsorbed organosilicon precursor. Thus, the RF plasma does not convert or only partially converts the adsorbed organosilicon precursor on the wafer surface.

[0064] Exposure to RF plasma can further treat the wafer surface to adjust or tune its hydrophobicity. It should be understood that exposure to RF plasma can have additional effects on the wafer surface and the silicon-containing layer with adsorbed organosilicon precursor. For example, exposure to RF plasma can stabilize the silicon-containing layer. Additionally or alternatively, exposure to RF plasma can activate crosslinking or polymerization of the silicon-containing layer.

[0065] By adjusting the conditions of RF plasma, the wafer surface can become more hydrophobic or less hydrophobic. Parameters such as RF power, chamber pressure, wafer temperature, chamber temperature, number of processing cycles, duration of processing cycles, RF exposure time and gas composition may affect the effect of RF plasma on the hydrophobicity of the wafer surface. In some implementations, the chamber pressure is between about 0.5 Torr and about 5 Torr. Higher chamber pressure may cause contact angle measurements to decrease, which is associated with reduced hydrophobicity. In some implementations, the RF exposure time is between about 0.25 seconds and about 50 seconds. An increase in RF exposure time may cause contact angle measurements to decrease, which is associated with reduced hydrophobicity. In some implementations, the number of processing cycles is between about 1 cycle and 7 cycles. An increase in the number of processing cycles may cause a decrease in contact angle measurements, which is associated with a decrease in hydrophobicity. Compared with the hydrophobicity of the wafer surface after adsorption of the organosilicon precursor, exposure to RF plasma can reduce the hydrophobicity of the wafer surface.

[0066] Figure 6C ALD deposited SiO is shown after processing according to some other implementations. x Contact angle measurements of ALD deposited SiO x The contact angle measurement of the ALD integrated surface treatment of the aminosilane precursor on the film was about 27° when exposed to an argon RF plasma after the ALD integrated surface treatment. The exposure to the argon RF plasma involved an RF power of 1000 W and an RF exposure time of 1 second. Figure 6C The contact angle measurements for the ALD integrated surface treatment with RF plasma exposure are higher than Fig. 6A , but the contact angle measurement is lower than Figure 6BTherefore, the effect of surface treatment integrated by ALD on hydrophobicity can be mitigated by RF plasma exposure. The RF plasma exposure can be designed in a way to achieve the desired hydrophobicity on the wafer surface. Various parameters of the RF plasma exposure can be adjusted to control the hydrophobicity of the wafer surface, such as Figures 7A-7C shown.

[0067] Fig. 7A A graph showing contact angle measurements as a function of the number of treatment cycles according to some implementations is shown, wherein each treatment cycle includes a dosing step and an RF plasma exposure step. Each treatment cycle represents at least an organosilicon precursor dosing phase and an inert gas plasma exposure phase. Fig. 7A Each process cycle in used a bis-diethylaminosilane precursor for a dosing time of 0.25 seconds and an argon plasma at a chamber pressure of 3 Torr, at an RF power of 400 W, for an RF exposure time of 0.25 seconds. Fig. 7A In the figure, the contact angle decreases with the increase of the number of treatment cycles.

[0068] Figure 7B A graph showing contact angle measurements as a function of chamber pressure during a process cycle according to some implementations, wherein each process cycle includes a dosing step and an RF plasma exposure step. Each process cycle represents at least an organosilicon precursor dosing phase and an inert gas plasma exposure phase. Figure 7B Each treatment cycle in used a bis-diethylaminosilane precursor for a dosing time of 0.25 seconds and an argon plasma at an RF power of 400 W for an RF exposure time of 0.25 seconds for one cycle and five cycles. Figure 7B In the experiment, as the chamber pressure increases, the contact angle decreases. As the chamber pressure increases, the contact angle stabilizes at about 34°.

[0069] Figure 7C A graph showing contact angle measurements as a function of RF exposure time during a process cycle according to some implementations is shown, wherein each process cycle includes a dosing step and an RF plasma exposure step. Each process cycle represents at least an organosilicon precursor dosing phase and an inert gas plasma exposure phase. Figure 7C Each treatment cycle in used a bis-diethylaminosilane precursor for a dosing time of 0.25 seconds and an argon plasma at 400 W RF power for one cycle. Figure 7C In the figure, the contact angle decreases with increasing RF exposure time. As the RF exposure time increases, the contact angle stabilizes at about 24°.

[0070] equipment

[0071] Figure 8is a schematic diagram of an exemplary processing chamber for performing implementations of the present disclosure. Figure 8 An atomic layer deposition (ALD) processing station 800 is depicted having a processing chamber body 802 for maintaining a low pressure environment. Multiple ALD processing stations 800 may be included in a common low pressure processing tool environment. For example, Fig. 9 An implementation of a multi-station processing tool 900 is depicted. In some implementations, one or more hardware parameters of the ALD processing station 800, including those discussed in detail below, can be programmatically adjusted by one or more system controllers 850. The ALD processing station 800 can be a system capable of performing the above-described processing steps for processing dielectric films (e.g., SiO x )’s ALD integrated surface treatment.

[0072] The ALD processing station 800 is in fluid communication with a reactant delivery system 801a to deliver process gases to a distribution showerhead 806. The reactant delivery system 801a includes a mixing vessel 804 for mixing and / or regulating process gases, such as aminosilane precursor gas or other precursor gas, oxygen-containing reactant gas (e.g., ozone), and / or nitrogen-containing reactant gas, delivered to the showerhead 806. One or more mixing vessel inlet valves 820 can control the introduction of process gases into the mixing vessel 804. Plasma can also be delivered to the showerhead 806 or can be generated in the ALD processing station 800.

[0073] For example, Figure 8 The implementation scheme includes a vaporization point 803 for vaporizing the liquid reactant to be supplied to the mixing container 804. In some implementation schemes, the vaporization point 803 can be a heated evaporator. The saturated reactant vapor produced from such an evaporator will condense in the downstream delivery pipeline. Incompatible gases exposed to condensed reactants will produce small particles. These small particles may block pipelines, hinder valve operation, contaminate substrates, etc. Some methods for dealing with these problems involve cleaning and / or emptying the delivery pipeline to remove residual reactants. However, cleaning the delivery pipeline will increase the processing station cycle time and reduce the processing station throughput. Therefore, in some implementation schemes, the delivery pipeline downstream of the vaporization point 803 can be heat traced. In some examples, the mixing container 804 can also be heat traced. In a non-limiting example, the pipeline downstream of the vaporization point 803 has an increased temperature distribution, extending from about 100°C to about 150°C at the mixing container 804.

[0074] In some implementations, the liquid precursor or liquid reactant can be vaporized at the liquid injector. For example, the liquid injector can inject a pulse of the liquid reactant into the carrier gas flow upstream of the mixing container. In one implementation, the liquid injector can vaporize the reactant by flashing the liquid from a higher pressure to a lower pressure. In another example, the liquid injector can atomize the liquid into dispersed droplets that are then vaporized in a heated delivery pipe. Smaller droplets can vaporize faster than larger droplets, thereby reducing the delay between liquid injection and completion of vaporization. Faster vaporization can reduce the length of the pipeline downstream of the vaporization point 803. In one embodiment, the liquid injector can be loaded directly into the mixing container 804. In another embodiment, the liquid injector can be loaded directly into the spray head 806.

[0075] In some implementations, a liquid flow controller (LFC) can be set upstream of the vaporization point 803 to control the mass flow of the liquid for vaporization and delivery to the processing station 800. For example, the LFC can include a thermal mass flow meter (MFM) located downstream of the LFC. The plunger valve of the LFC can then be adjusted in response to a feedback control signal provided by a proportional integral differential (PID) controller that is electrically communicated with the MFM. However, it can take one second or more to use feedback control to stabilize the liquid flow. This can extend the time of dosing liquid reactants. Therefore, in some implementations, the LFC can be dynamically switched between feedback control mode and direct control mode. In some implementations, this can be performed by disabling the sensing pipeline of the PID controller and the LFC.

[0076] Showerhead 806 distributes processing gas toward wafer 812. Figure 8 In the illustrated implementation, wafer 812 is positioned below showerhead 806 and is shown resting on pedestal 808. Showerhead 806 may have any suitable shape and may have any suitable number and arrangement of ports to distribute process gases to wafer 812.

[0077] In some implementations, the pedestal 808 can be raised or lowered to expose the wafer 812 to the volume between the wafer 812 and the showerhead 806. It should be appreciated that in some implementations, the pedestal height can be programmatically adjusted via a suitable computer controller 850.

[0078] In another case, in an implementation where the plasma is ignited, adjusting the height of the pedestal 808 can allow the plasma density to be varied during a plasma activation cycle in the process. At the end of the processing phase, the pedestal 808 can be lowered to allow the wafer 812 to be removed from the pedestal 808 in another substrate transfer phase.

[0079] In some implementations, the temperature of the susceptor 808 can be controlled by a heater 810. In some implementations, the susceptor 808 can be heated to a temperature of at least about 250°C, or in some implementations, it can be heated to less than about 300°C, such as being heated to about 250°C during deposition of a silicon oxide film as described in the disclosed implementations. In some implementations, the susceptor 808 is set to a temperature between about 50°C and about 300°C, such as a temperature between about 200°C and about 275°C. In some implementations, the susceptor 808 is set to a temperature between about 50°C and about 300°C. In some implementations, the susceptor 808 is set to a temperature between about 200°C and about 275°C.

[0080] Additionally, in some implementations, pressure control for the processing station 800 may be provided by a butterfly valve 818. Figure 8 In the embodiment shown in FIG. 8 , the butterfly valve 818 throttles the vacuum provided by the downstream vacuum pump (not shown). However, in some embodiments, the pressure control of the process station 800 can also be adjusted by changing the flow rate of one or more gases introduced into the process station 800.

[0081] In some implementations, the position of the showerhead 806 can be adjusted relative to the pedestal 808 to change the volume between the wafer 812 and the showerhead 806. In addition, it should be understood that the vertical position of the pedestal 808 and / or the showerhead 806 can be changed by any suitable mechanism within the scope of the present disclosure. In some implementations, the pedestal 808 can include a rotation axis for rotating the orientation of the wafer 812. It should be understood that in some implementations, one or more of these exemplary adjustments can be performed programmatically by one or more appropriate system controllers 850.

[0082] In some implementations where plasma can be used as described above, the showerhead 806 and the base 808 are electrically connected to a radio frequency (RF) power source 814 and a matching network 816 to provide power to the plasma. In some implementations, the energy of the plasma can be controlled by controlling one or more of the pressure of the processing station, the concentration of the gas, the RF source power, the RF source frequency, and the timing of the plasma power pulse. For example, the RF power source 814 and the matching network 816 can be operated at any suitable power to form a plasma having a component of a desired free radical substance. An example of a suitable power is about 150W to about 6000W. Before the photoresist is deposited on the silicon oxide surface, the plasma can be used during the treatment of the silicon oxide surface. The RF power source 814 can provide RF power of any appropriate frequency. In some implementations, the RF power source 814 can be configured to control a high frequency RF power source and a low frequency RF power source that are independent of each other. Exemplary low frequency RF frequencies can include, but are not limited to, frequencies between 0kHz and 500kHz. Exemplary high frequency RF frequencies may include, but are not limited to, frequencies between 1.8 MHz and 2.45 GHz, or frequencies greater than about 13.56 MHz, or greater than 27 MHz, or greater than 40 MHz, or greater than 60 MHz. It should be understood that any suitable parameter may be discretely or continuously adjusted to provide plasma energy for surface reactions.

[0083] In some implementations, the plasma may be monitored in situ by one or more plasma monitors. In one case, the plasma power may be monitored by one or more voltage and current sensors (e.g., VI probes). In another case, the plasma density and / or the concentration of the process gas may be measured by one or more optical emission spectroscopy sensors (OES). In some implementations, one or more plasma parameters may be adjusted programmatically based on the measurement results from such an in-situ plasma monitor. For example, an OES sensor may be used in a feedback loop to provide programmatic control of the plasma power. It should be understood that in some implementations, other monitors may be used to monitor plasma and other process characteristics. Such monitors may include, but are not limited to, infrared (IR) monitors, acoustic monitors, and pressure sensors.

[0084] In some implementations, instructions for the system controller 850 may be provided via input / output control (IOC) sequencing instructions. In one example, instructions for setting conditions for a process stage may be included in a corresponding recipe stage of a process recipe. In some cases, the process recipe stages may be arranged in sequence so that all instructions for a process stage are executed simultaneously with the process stage. In some implementations, instructions for setting one or more reactor parameters may be included in a recipe stage. For example, a first recipe stage may include instructions for setting the flow rate of a precursor gas, instructions for setting the flow rate of a carrier gas (e.g., argon), instructions for setting the flow rate of a reactant gas, instructions for igniting a plasma, and time delay instructions for the first recipe stage. A subsequent second recipe stage may include instructions for adjusting or stopping the flow rate of an inert gas and / or a reactant gas, instructions for adjusting the flow rate of a carrier gas or a purge gas, and time delay instructions for the second recipe stage. A subsequent third recipe stage may include instructions for setting the flow rate of the organosilicon precursor gas, instructions for setting the flow rate of a carrier gas (e.g., argon), instructions for igniting an inert gas plasma, and time delay instructions for the third recipe stage. A subsequent fourth recipe stage may include instructions for adjusting or stopping the flow rate of the organosilicon precursor gas, and instructions for adjusting the flow rate of a carrier gas or a purge gas, and time delay instructions for the fourth recipe stage. It should be understood that within the scope of the embodiments of the present disclosure, these recipe stages may be further subdivided and / or repeated in any appropriate manner. In some embodiments, the system controller 850 may include the following instructions regarding Fig. 9 Any features described for system controller 950.

[0085] As described above, one or more processing stations may be included in a multi-station processing tool. Fig. 9 is a schematic diagram of an example processing tool for performing disclosed implementations. Fig. 9An implementation of a multi-station processing tool 900 is shown, wherein the processing tool 900 has an inbound load lock 902 and an outbound load lock 904, either or both of which may include a remote plasma source. A robot 906 at atmospheric pressure is configured to move a wafer from a box loaded by a wafer boat 908 into the inbound load lock 902 via an atmospheric port 910. The wafer is placed on a pedestal 912 in the inbound load lock 902 by the robot 906, the atmospheric port 910 is closed, and the load lock is evacuated. When the inbound load lock 902 includes a remote plasma source, the wafer can be exposed to a remote plasma treatment in the load lock to treat the silicon oxide surface before being introduced into the processing chamber 914. In addition, the wafer can also be heated in the inbound load lock 902, for example to remove moisture and adsorbed gases. Next, a chamber transfer port 916 leading to the processing chamber 914 is opened, and another robot (not shown) places the wafer into the reactor on the pedestal of the first station shown in the reactor for processing. Although in Fig. 9 The implementation depicted in FIG. 1 includes a load lock, but it should be understood that in some implementations, wafers may be allowed to enter the processing station directly.

[0086] The processing chamber 914 depicted includes four processing stations, Fig. 9 The stations are numbered 1 to 4 in the illustrated implementation. Each station has a heated susceptor (shown as 918 for station 1) and a gas line inlet. It should be understood that in some implementations, each processing station may have different or multiple uses. For example, in some implementations, a processing station may be switchable between ALD and plasma-enhanced ALD processing modes. Additionally or alternatively, in some implementations, the processing chamber 914 may include one or more matched pairs of ALD and plasma-enhanced ALD processing stations. Although the depicted processing chamber 914 includes 4 stations, it is to be understood that a processing chamber according to the present disclosure may have any suitable number of stations. For example, in some implementations, a processing chamber may have 5 or more stations, while in other implementations, a processing chamber may have 3 or fewer stations.

[0087] Fig. 9 One implementation of a wafer handling system 990 for transferring wafers within a processing chamber 914 is depicted. In some implementations, the wafer handling system 990 can transfer wafers between various processing stations and / or between a processing station and a load lock. It should be understood that any suitable wafer handling system can be employed. Non-limiting examples include a wafer turntable and a robot for handling wafers. Fig. 9Also depicted is one implementation of a system controller 950 employed to control process conditions and hardware states of the processing tool 900. The system controller 950 may include one or more memory devices 956, one or more mass storage devices 954, and one or more processors 952. The processor 952 may include a computer or CPU, analog and / or digital input / output connections, a stepper motor controller board, and the like.

[0088] In some implementations, the system controller 950 controls all activities of the processing tool 900. The system controller 950 executes system control software 958 stored in the mass storage device 954, loaded into the memory device 956, and executed by the processor 952. Alternatively, the control logic can be hard-coded in the system controller 950. Application-specific integrated circuits, programmable logic devices (e.g., field programmable gate arrays, or FPGAs), etc. can be used for these purposes. In the following discussion, whether "software" or "code" is used, functionally equivalent hard-coded logic can be used instead. The system control software 958 can include instructions for controlling timing, mixing of gases, gas flow rates, chamber and / or station pressures, chamber and / or station temperatures, wafer temperatures, target power levels, RF power levels, substrate pedestals, chuck and / or pedestal positions, and other parameters of a specific process performed by the processing tool 900. The system control software 958 can be configured in any suitable manner. For example, various processing tool component subroutines or control objects can be written to control the operation of the processing tool components used to perform various processing tool processes. The system control software 958 may be coded in any suitable computer readable programming language.

[0089] In some implementations, the system control software 958 may include input / output control (IOC) sequencing instructions for controlling the various parameters described above. Other computer software and / or programs associated with the system controller 950 and stored in the mass storage device 954 and / or the memory device 956 may be employed in some implementations. Examples of programs or program segments for this purpose include wafer positioning programs, process gas control programs, pressure control programs, heater control programs, and plasma control programs.

[0090] The wafer positioning program may contain program code for the processing tool components used to load the wafer into the pedestal 918 and control the spacing between the wafer and other parts of the processing tool 900.

[0091] The process gas control program may include code for controlling gas composition (e.g., silicon-containing precursor gas, organosilicon precursor, oxygen-containing reactant gas, nitrogen-containing reactant gas, carrier gas, and / or purge gas as described herein) and flow rate and optionally code for flowing gas into one or more process stations prior to deposition to stabilize the pressure in the process station. The pressure control program may include code for controlling the pressure within a process station by adjusting, for example, a throttle valve in an exhaust system of the process station, gas flow into the process station, and the like.

[0092] The heater control program may contain code for controlling the flow of current to a heating unit used to heat the wafer.Alternatively, the heater control program may control the delivery of a heat transfer gas (such as helium) toward the wafer.

[0093] A plasma control program may include code for setting RF power levels applied to process electrodes within one or more process stations according to implementations herein.

[0094] The pressure control program may include code for maintaining the pressure within the reaction chamber according to implementations herein.

[0095] In some implementations, there may be a user interface associated with the system controller 950. The user interface may include a display screen, graphical software displays of equipment and / or process conditions, and user input devices such as a pointing device, keyboard, touch screen, microphone, and the like.

[0096] In some implementations, the parameters adjusted by the system controller 950 will relate to process conditions. Non-limiting examples include process gas composition and flow rate, temperature, pressure, plasma conditions (e.g., RF bias power level), etc. These parameters can be provided to the user in the form of a recipe, which can be entered using the user interface.

[0097] Signals for monitoring the process may be provided from various process tool sensors by analog and / or digital input connections of the system controller 950. Signals for controlling the process may be output by analog and / or digital output connections of the process tool 900. Non-limiting examples of process tool sensors that may be monitored include mass flow controllers, pressure sensors (e.g., manometers), thermocouples, etc. Appropriately programmed feedback and control algorithms may be used with the data from these sensors to maintain process conditions.

[0098] The system controller 950 may provide program instructions for performing the above-described deposition process. The program instructions may control various process parameters, such as DC power level, RF bias power level, pressure, temperature, etc. The instructions may control these parameters to operate the in-situ deposition and surface treatment of the film stack according to the various implementations described herein.

[0099] The system controller 950 will typically include one or more memory devices and one or more processors configured to execute instructions so that the apparatus will perform the methods described in accordance with the disclosed implementations. A machine-readable medium containing instructions for controlling processing operations in accordance with the disclosed implementations may be coupled to the system controller 950.

[0100] In some implementations, the system controller 950 is part of a system, which can be part of the above examples. Such a system can include a semiconductor processing device, which includes one or more processing tools, one or more processing chambers, one or more platforms for processing, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems can be integrated with electronic devices for controlling their operation before, during, and after processing semiconductor wafers or wafers. The electronic device can be referred to as a "controller", which can control various elements or subcomponents of one or more systems. Depending on the processing requirements and / or the type of system, the system controller 950 can be programmed to control any process disclosed herein, including controlling process gas delivery, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and operation settings, wafer transfer in and out of tools and other transfer tools and / or load locks connected to or connected to a specific system through an interface.

[0101] In broad terms, the system controller 950 may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receives instructions, issues instructions, controls operations, enables cleaning operations, enables endpoint measurements, and the like. The integrated circuit may include a chip in the form of firmware storing program instructions, a digital signal processor (DSP), a chip defined as an application specific integrated circuit (ASIC), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). The program instructions may be instructions transmitted to the system controller 950 in the form of various separate settings (or program files) that define operating parameters for performing a particular process on or for a semiconductor wafer or system. In some implementations, the operating parameters may be part of a recipe defined by a process engineer for completing one or more process steps during the preparation of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0102] In some implementations, the system controller 950 may be part of or coupled to a computer that is integrated with, coupled to, or connected to the system via a network, or a combination thereof. For example, the system controller 950 may be in the "cloud" or all or part of a fab host system, thereby allowing remote access to wafer processing. The computer may enable remote access to the system to monitor the current progress of a manufacturing operation, examine the history of past manufacturing operations, examine trends or performance criteria for multiple manufacturing operations, to change parameters of a current process, set processing steps to follow a current process, or start a new process. In some examples, a remote computer (e.g., a server) may provide a process recipe to the system via a network, which may include a local network or the Internet. The remote computer may include a user interface that allows input or programming of parameters and / or settings, which are then transmitted from the remote computer to the system. In some examples, the system controller 950 receives instructions in the form of data that specify parameters for each processing step to be performed during one or more operations. It should be understood that the parameters may be for the type of process to be performed and the type of tool to which the system controller 950 is configured to connect or control the tool type. Thus, as described above, the system controller 950 can be distributed, for example, by including one or more discrete controllers that are networked together and work toward a common goal (e.g., the processes and controls described herein). An example of a distributed controller for these purposes can be one or more integrated circuits on the chamber that communicate with one or more remote integrated circuits (e.g., at a platform level or as part of a remote computer) that are combined to control the processes within the chamber.

[0103] Example systems may include, but are not limited to, plasma etch chambers or modules, deposition chambers or modules, spin cleaning chambers or modules, metal plating chambers or modules, cleaning chambers or modules, chamfer edge etch chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, ALD chambers or modules, atomic layer etch (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and any other semiconductor processing system that may be associated with or used in the preparation and / or manufacture of semiconductor wafers.

[0104] As described above, depending on one or more process steps to be performed by the tool, the system controller 950 can communicate with one or more other tool circuits or modules, other tool components, combination tools, other tool interfaces, adjacent tools, adjacent tools, tools located throughout the factory, a host computer, another controller, or tools used in material handling to move containers of wafers to and from tool locations and / or load ports in a semiconductor manufacturing facility.

[0105] The system controller 950 can control the activities of the processing tool 900. In some implementations, the system controller 950 includes instructions for performing the following operations: (a) depositing a silicon-containing layer on a wafer by ALD in a processing chamber, and (b) introducing a certain amount of a gas-phase organosilicon precursor to the surface of the wafer in the processing chamber to increase the hydrophobicity of the surface of the wafer. The operations in (a) and (b) can be performed without introducing a vacuum interruption between the operations. Depositing the silicon-containing layer includes at least one or more ALD cycles, wherein each ALD cycle includes introducing a certain amount of a silicon-containing precursor to the surface of the wafer and converting the silicon-containing precursor to form an adsorption-limited amount of a silicon-containing layer. The conversion of the silicon-containing precursor can be performed by thermal conversion or plasma conversion using a reactant substance. In some implementations, the silicon-containing layer includes silicon nitride, silicon carbide, silicon carbide, or a combination thereof, and introducing a certain amount of an organosilicon precursor includes adsorbing the organosilicon precursor on the surface of the wafer without converting the organosilicon precursor to silicon in an ALD cycle. In some implementations, the controller further includes instructions for: (c) exposing the wafer to an inert gas RF plasma. In some implementations, the controller further includes instructions for: transferring the wafer from the processing chamber to a deposition chamber configured to deposit a photoresist on the silicon-containing layer. After introducing a certain dose of the organosilicon precursor, the adhesion between the photoresist and the silicon-containing layer may be strong.

[0106] The apparatus / processes described herein can be used in conjunction with photolithographic patterning tools or processes, e.g., for preparing or manufacturing semiconductor devices, displays, LEDs, photovoltaic panels, etc. Typically, though not necessarily, these tools / processes will be used or operated together in a common manufacturing facility. Photolithographic patterning of films typically involves some or all of the following operations, each of which enables multiple available tools: (1) applying photoresist on a workpiece (i.e., wafer) using a spin coating or spray coating tool; (2) curing the photoresist using a hot plate or oven or UV curing tool; (3) exposing the photoresist to visible light or ultraviolet light or x-rays using a tool such as a wafer stepper; (4) developing the resist so as to selectively remove the resist and thereby pattern it using a tool such as a wet bench; (5) transferring the resist pattern to an underlying film or workpiece by using a dry or plasma assisted etching tool; and (6) removing the resist using a tool such as an RF or microwave plasma resist stripper.

[0107] in conclusion

[0108] In the foregoing description, many specific details are set forth to provide a thorough understanding of the implementation scheme presented. The disclosed implementation scheme may be practiced without some or all of these specific details. In other cases, well-known processing operations are not described in detail so as not to unnecessarily make the disclosed implementation scheme unclear. Although the disclosed implementation scheme is described in conjunction with a specific implementation scheme, it should be understood that it is not intended to limit the disclosed implementation scheme.

[0109] Although the above implementation has been described in detail for the purpose of clarity of understanding, it is apparent that certain changes and modifications may be implemented within the scope of the appended claims. It should be noted that there are many alternative ways to implement the processes, systems and devices of the implementation of the present invention. Therefore, the implementation of the present invention should be considered to be illustrative rather than restrictive, and the implementation of the present invention should not be limited to the details set forth herein.

Claims

1. A method for increasing the hydrophobicity of a wafer surface, the method comprising: depositing a silicon-containing layer on the wafer by atomic layer deposition; introducing a dose of a vapor phase organosilicon precursor onto the wafer surface to increase the hydrophobicity of the wafer surface; as well as Subsequent to introducing the dose of the organosilicon precursor, the wafer is exposed to an RF plasma, wherein the RF plasma comprises an inert gas plasma, wherein conditions associated with the inert gas plasma modulate the hydrophobicity of the wafer surface.

2. The method of claim 1, wherein the RF power applied to the RF plasma is between 100 W and 1000 W.

3. The method of claim 2, wherein a chamber pressure when exposing the wafer to the RF plasma is between 0.5 Torr and 5 Torr, and wherein an exposure time when exposing the wafer to the RF plasma is between 0.25 seconds and 50 seconds.

4. The method according to claim 1, wherein: Depositing the silicon-containing layer by atomic layer deposition comprises: introducing a dose of a silicon-containing precursor onto the wafer surface; and The silicon-containing precursor is converted to form an adsorption-limited amount of the silicon-containing layer.

5. The method according to any one of claims 1 to 4, further comprising: The wafer is transferred from the atomic layer deposition chamber to a deposition chamber configured to deposit a photoresist on the silicon-containing layer.

6. The method of any one of claims 1-4, wherein introducing the dose of the organosilicon precursor comprises adsorbing the organosilicon precursor on the wafer surface without converting the organosilicon precursor in an atomic layer deposition cycle.

7. The method according to any one of claims 1 to 4, further comprising: Prior to introducing the dose of the organosilicon precursor, a hydrophobic layer is deposited on the silicon-containing layer, wherein the hydrophobic layer comprises hexamethyldisilazane (HMDS) or polydimethylsiloxane (PDMS).

8. An apparatus for increasing the hydrophobicity of a wafer surface, the apparatus comprising: a processing chamber, wherein the processing chamber includes a wafer support for supporting a wafer; and A controller including instructions for: (a) depositing a silicon-containing layer on the wafer by atomic layer deposition in the processing chamber; (b) introducing a certain amount of gas phase organosilicon precursor to the surface of the wafer in the processing chamber to increase the hydrophobicity of the surface of the wafer; as well as (c) exposing the wafer to an RF plasma after introducing the dose of the organosilicon precursor, wherein the RF plasma comprises an inert gas plasma, wherein conditions associated with the inert gas plasma modulate the hydrophobicity of the wafer surface.

9. The device according to claim 8, wherein: The silicon-containing layer comprises silicon nitride, silicon carbide, silicon oxide, or a combination thereof, and wherein introducing the dose of the organosilicon precursor comprises adsorbing the organosilicon precursor on the wafer surface without converting the organosilicon precursor during an atomic layer deposition cycle.

10. The device according to claim 8 or 9, wherein: The controller also includes instructions for: (d) transferring the wafer from the processing chamber to a deposition chamber configured to deposit a photoresist on the silicon-containing layer.

Images