Method and apparatus for processing substrate

Abstract

Methods and apparatus for processing a substrate are provided herein. For example, a method for processing a substrate includes forming a plasma reaction between titanium tetrachloride (TiCl4), hydrogen (H2), and argon (Ar) in a region between a cap heater and a showerhead of a processing chamber or between the showerhead and a substrate while providing RF power at a pulse frequency of about 5 kHz to about 100 kHz and a duty cycle of about 10% to about 20%; and flowing the reaction product into a processing chamber to selectively form a titanium material layer on the silicon surface of the substrate.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to methods and apparatus for processing substrates, and, for example, to methods and apparatus using plasma tuning during remote plasma chemical vapor deposition (CVD). Background Art

[0002] Selective deposition processes can advantageously reduce the number of steps and costs involved in conventional lithography while keeping pace with device size reduction. Selective deposition in titanium / titanium silicide dielectric patterns is of high potential value because titanium and titanium silicide (TiSix) are important materials widely used to form ohmic contacts and reduce the contact resistance of transistor connections. The inventors have found that remote plasma selective CVD TiSix deposition suffers from the problem of uncontrollable particles due to the accumulation of a large amount of byproducts in the remote cavity by the TiCl4-H2 plasma.

[0003] Accordingly, the present inventors have developed improved methods and apparatus for using plasma tuning during remote plasma chemical vapor deposition (CVD). Summary of the invention

[0004] Methods and apparatus for processing substrates are provided herein. In some embodiments, a method for processing a substrate includes forming a plasma reaction between titanium tetrachloride (TiCl4), hydrogen (H2) and argon (Ar) in a region between a lid heater and a showerhead of a processing chamber or between the showerhead and a substrate, while providing RF power at a pulse frequency of about 5 kHz to about 100 kHz and a duty cycle of about 10% to about 20%, and flowing a reaction product into the processing chamber to selectively form a titanium material layer on a silicon surface of the substrate.

[0005] According to at least some embodiments, a non-transitory computer-readable storage medium has instructions stored thereon that, when executed by a processor, perform a method for processing a substrate, the method including forming a plasma reaction between titanium tetrachloride (TiCl4), hydrogen (H2), and argon (Ar) in a region between a lid heater and a showerhead of a processing chamber or between the showerhead and a substrate while providing RF power at a pulse frequency of about 5 kHz to about 100 kHz and a duty cycle of about 10% to about 20%, and flowing reaction products into the processing chamber to selectively form a titanium material layer on a silicon surface of the substrate.

[0006] According to at least some embodiments, a processing system for processing a substrate includes: a processing chamber defining a processing volume disposed in a region between a lid heater and a showerhead or in a region between the showerhead and a substrate; an RF power source; a gas panel connected to the lid heater and the showerhead; and a controller configured to form a plasma reaction between titanium tetrachloride (TiCl4), hydrogen (H2) and argon (Ar) in a region between the lid heater and the showerhead or between the showerhead and the substrate, while providing RF power at a pulse frequency of about 5 kHz to about 100 kHz and a duty cycle of about 10% to about 20%, and flowing reaction products into the processing chamber to selectively form a titanium material layer on a silicon surface of the substrate.

[0007] Other and further embodiments of the disclosure are described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] By reference to the illustrative embodiments of the present disclosure depicted in the attached figures, the embodiments of the present disclosure briefly summarized above and discussed in more detail below can be understood. However, the attached figures only illustrate typical embodiments of the present disclosure and therefore should not be considered as limiting the scope, because the present disclosure may allow other equivalent embodiments.

[0009] Figure 1 is a schematic diagram of an apparatus, such as a substrate processing system, in accordance with at least some embodiments of the present disclosure.

[0010] Figure 2 For use according to at least some embodiments of the present disclosure Figure 1 A flow chart of a method for processing a substrate using a substrate processing system.

[0011] Figure 3A and Figure 3B For use according to at least some embodiments of the present disclosure Figure 1 Substrate processing system and Figure 2 A diagram of a substrate manufactured by the method.

[0012] For ease of understanding, the same reference numerals have been used, where possible, to represent the same elements common to the figures. The figures are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be beneficially incorporated into other embodiments without further description. DETAILED DESCRIPTION

[0013] Methods and apparatus for selective deposition are provided herein. For example, a method for processing a substrate includes: forming a plasma reaction between titanium tetrachloride (TiCl4), hydrogen (H2) and argon (Ar) in a region between a lid heater and a showerhead of a processing chamber or between the showerhead and a substrate, while providing RF power at a pulse frequency of about 5 kHz to about 100 kHz and a duty cycle of about 10% to about 20%. The method also includes: flowing the reaction products into the processing chamber to selectively form a titanium material layer on a silicon surface of the substrate. The inventors have found that by tuning the RF plasma pulse frequency and duty cycle, minimal byproducts are produced and the far end channel of the processing chamber remains relatively clean, which improves the productivity of highly selective TiSix deposition.

[0014] Figure 1 Schematic diagram of an apparatus suitable for practicing the methods of the present disclosure, such as a wafer processing system 10. In an embodiment, the wafer processing system 10 includes a processing chamber 100, a gas panel 130, a control unit 110, and other hardware components such as a power supply and a vacuum pump. An exemplary processing chamber may include any of several processing chambers available from Applied Materials, Inc., Santa Clara, California, configured for remote and direct chemical vapor deposition (CVD) reactions as described herein. Other suitable processing chambers from other manufacturers may be similarly used and modified according to the present disclosure.

[0015] In an embodiment, the processing chamber 100 generally includes a lid heater 131 that is used to heat a processing volume 101 within the processing chamber 100, the processing volume including an area such as the plenum space between the lid heater 131 and the showerhead 165. Depending on the specific process, the processing volume 101 in the area between the lid heater 131 and the showerhead 165 can be heated to a desired temperature before and during processing according to the present disclosure. In an embodiment, the lid heater 131 is heated by an embedded heating element such as a heating element 171. For example, the lid heater 131 can be resistively heated by applying current from an AC power source (not shown) to the heating element 171. The processing volume 101 area between the lid heater 131 and the showerhead 165 is then heated by the lid heater 131 and can be maintained within a processing temperature range of, for example, 200 degrees Celsius to 800 degrees Celsius, or at a first temperature of about 550 degrees Celsius. In some embodiments, the region between the lid heater and the showerhead of the processing chamber is maintained at a first temperature of 200 degrees Celsius to 800 degrees Celsius. In some embodiments, providing a lid heater at a temperature of 200 degrees Celsius to 800 degrees Celsius, or in some embodiments, about 550 degrees Celsius, a showerhead at about 500 degrees Celsius (heated by radiant heat from the lid heater), a wafer temperature at about 425 degrees Celsius, and a susceptor heated to about 450 degrees Celsius can heat the region between the lid heater and the showerhead to a temperature of 200 degrees Celsius to 800 degrees Celsius, or in some embodiments, about 550 degrees Celsius. In an embodiment, the region between the lid heater and the showerhead is characterized as a plenum space.

[0016] In an embodiment, a temperature sensor (not shown), such as a thermocouple, may be embedded in the lid heater 131 to monitor the temperature of the lid heater 131 in a conventional manner. For example, the measured temperature may be used in a feedback loop to control a power supply for the lid heater 131 so that the temperature of the processing volume 101 in the area between the lid heater 131 and the showerhead 165 may be maintained or controlled at a desired temperature suitable for a particular processing application. In an embodiment, the lid heater 131 is configured to provide heat sufficient to promote remote plasma formation in the processing volume 101 between the lid heater 131 and the showerhead 165 or within the showerhead 165 and to prevent condensation in or on the showerhead 165. For example, the control unit 110 may communicate with the lid heater 131 so that a user can adjust the heat of the lid heater 131 and maintain heat sufficient for remote plasma formation. In an embodiment, depending on the processing needs, the lid heater 131 is configured not to heat or promote remote plasma formation in the processing volume 101 in the area between the lid heater 131 and the showerhead 165. For example, the lid heater 131 may be turned off by the control unit 110 depending on user needs.

[0017] In an embodiment, an RF electrode 181 may be embedded in the lid heater 131 to configure the lid heater 131 to provide RF in an amount sufficient to form a plasma adjacent to the lid heater 131. In an embodiment, the lid heater 131 is configured to provide RF sufficient to facilitate remote plasma formation in the processing volume 101 in the area between the lid heater 131 and the showerhead 165 and / or within the showerhead 165. For example, the control unit 110 may communicate with the lid heater 131 so that a user can adjust the RF emitted from the lid heater 131 and maintain an RF signal sufficient for plasma formation. In an embodiment, depending on the processing needs, the lid heater 131 is configured not to emit an RF signal or not to facilitate plasma formation in the processing volume 101 between the lid heater 131 and the showerhead 165. For example, the lid heater 131 may be turned off with the help of the control unit 110 depending on the user's need to eliminate the RF generated thereby.

[0018] In an embodiment, the processing chamber 100 generally includes a support pedestal 150 for supporting a substrate (such as a semiconductor substrate 190) within the processing chamber 100. The support pedestal 150 may be moved in a vertical direction within the processing chamber 100 using a shifting mechanism (not shown). Depending on the particular process, the semiconductor substrate 190 may be heated to a desired temperature prior to processing. In an embodiment, the support pedestal 150 is heated by an embedded heating element (such as a heating element 170). For example, the support pedestal 150 may be resistively heated by applying a current from an AC power source 106 to the heating element 170. The semiconductor substrate 190 is then heated by the support pedestal 150 and may be maintained within a processing temperature range of, for example, 200 degrees Celsius to 800 degrees Celsius or 300 degrees Celsius to 700 degrees Celsius. In an embodiment, a temperature sensor 172, such as a thermocouple, may be embedded in the support pedestal 150 to monitor the temperature of the support pedestal 150 in a conventional manner. For example, the measured temperature can be used in a feedback loop to control a power supply (such as AC power supply 106) for heating element 170 so that the semiconductor substrate 190 temperature can be maintained or controlled at a desired temperature suitable for a particular processing application. In an embodiment, the support base includes a ground line at 182.

[0019] In an embodiment, appropriate control and regulation of the gas flow through the process chamber 100 and the gas panel 130 is performed by a mass flow controller (not shown) and a controller unit 110 (such as a computer). The showerhead 165 allows the process gas from the gas panel 130 to be evenly distributed and introduced into the process chamber 100. In an embodiment, the showerhead 165 is configured to flow a reaction product (such as a reaction product suitable for forming a titanium material layer of titanium or titanium silicide as described herein) into the process chamber to selectively form a titanium material layer on a silicon surface of a substrate.

[0020] Illustratively, the control unit 110 includes a central processing unit (CPU) 112, support circuitry 114, and memory containing associated control software 116. The control unit 110 is responsible for automated control of the various steps required for processing the semiconductor substrate 190 (e.g., wafer transport, gas flow control, temperature control, chamber evacuation, etc.). The control unit 110 is connected to the semiconductor substrate 190 via a plurality of signal cables (in the form of a bus 118) collectively referred to as a signal bus. Figure 1 ) to handle bidirectional communications between the control unit 110 and the various components of the wafer processing system 10.

[0021] In some embodiments, the present disclosure relates to a non-transitory computer-readable medium (such as a memory) having instructions stored thereon, which when executed will result in a method for selectively depositing a titanium material layer atop a substrate having a silicon surface and a dielectric surface, the method comprising: forming a remote plasma reaction between titanium tetrachloride (TiCl4), hydrogen (H2) and argon (Ar) in a region between a lid heater and a showerhead of a processing chamber at a first temperature of 200 degrees Celsius to 800 degrees Celsius; and flowing the reaction products into the processing chamber to selectively form a titanium material layer on the silicon surface of the substrate.

[0022] In some embodiments, an RF electrode 181 may be embedded in the showerhead 165 to configure the showerhead 165 to provide RF energy in an amount sufficient to form a plasma adjacent to the showerhead 165. In embodiments, the showerhead 165 is configured to provide RF sufficient to facilitate plasma formation in the processing volume 101. For example, the control unit 110 may communicate with the showerhead 165 so that a user can adjust the RF emitted from the showerhead 165 and maintain an RF signal sufficient to form a plasma. In embodiments, the showerhead 165 may be optionally grounded by the ground wire 183 depending on user needs for plasma placement within the processing volume 101. In embodiments where the showerhead 165 is grounded, a remote plasma may be formed in the processing volume 101 in a region between the lid heater 131 and the showerhead 165. In embodiments where the showerhead is not grounded, a direct plasma is formed in the processing volume 101 in a region between the showerhead 165 and the semiconductor substrate 190. The switch 184 can be in communication with the ground 183 and the RF electrode 180 and the showerhead, and can be configured to control remote and direct plasma formation according to the present disclosure and depending on the needs of the user. In an embodiment, the switch 184 is in communication with the showerhead 165, and can be configured to control remote and direct plasma formation according to the present disclosure and depending on the needs of the user. In some embodiments, when the switch is set in a first position, a power supply (such as an RF or VHF power supply) is electrically coupled to the chamber lid via the switch 184. When the switch is set in a second position (not shown), the power supply is electrically coupled to the showerhead 165. When the switch 184 is in the first position, the power supply is used to ignite and maintain a first plasma away from the substrate, such as a remote plasma disposed in a plenum space or region directly between the lid heater and the showerhead. In some embodiments, the remote plasma is composed of a process gas flowing into the plenum and is maintained as a plasma by capacitive coupling of power from the power supply. In some embodiments, when the switch 184 is in the second position, the power supply is used to ignite and maintain a second plasma (not shown) in the processing volume 101 between the showerhead 165 and the semiconductor substrate 190 disposed on the substrate support.

[0023] In an embodiment, the processing chamber 100 includes a vacuum pump 102 to evacuate the processing chamber 100 and maintain appropriate gas flow and pressure inside the processing chamber 100. A showerhead 165 is located above the support pedestal 150, and a process gas system is introduced into the processing chamber 100 through the showerhead 165. In an embodiment, the showerhead 165 can be configured as a multi-channel gas showerhead having two or more separate paths, which allows two or more gases to be introduced into the processing chamber 100 separately without pre-mixing. In some embodiments, the showerhead 165 is connected to a gas panel 130, which controls and supplies various gases used in different steps of the processing sequence via a mass flow controller (not shown). During wafer processing, the purge gas supply 104 also provides a purge gas (e.g., an inert gas) around the bottom of the support pedestal 150 to minimize undesirable deposition formed on the support pedestal 150.

[0024] In an embodiment, the control unit 110 is responsible for controlling the flow of gas from the gas panel 130 to the processing volume 101 (such as, the area between the lid heater 131 and the showerhead 165) through the first gas flow line 162, or the flow of gas within the showerhead 165 through the second gas flow line 163. In some embodiments, the processing chamber 100 is configured so that the gas panel 130 provides titanium tetrachloride (TiCl4), hydrogen (H2) and / or argon (Ar) or an inert gas inside the processing chamber 100 and the processing volume 101. For example, in an embodiment, the processing volume 101 is configured to receive titanium tetrachloride (TiCl4) at about 1 sccm to 100 sccm, or about 25 sccm. In an embodiment, the processing volume 101 is configured to receive hydrogen (H2) at about 50 sccm to 10000 sccm, or about 500 sccm. In an embodiment, the processing volume 101 is configured to receive about 3.5 liters of argon. In some embodiments, one or more desired gases may be directed from the gas panel 130 into the processing volume 101 via the second gas flow line 163. For example, in embodiments, silane (such as SiH4), disilane (such as Si2H6), a silane compound, or hydrogen (H2), or an inert gas (such as argon (Ar) gas) may be added to the processing volume 101 via the second gas flow line 163. In some embodiments, such as embodiments where the processing chamber 100 is configured for remote plasma applications (e.g., igniting a plasma in a region between the lid heater 131 and the showerhead 165 or within the showerhead 165), one or more desired gases (such as titanium tetrachloride (TiCl4), hydrogen (H2), and / or argon (Ar)) may be directed from the gas panel 130 into the processing volume 101 via the first gas flow line 162, and one or more desired gases (such as silane such as SiH4, or hydrogen (H2), or argon (Ar) gas) may be directed into the processing volume 101 via the second gas flow line 163. In some embodiments, including silane during the deposition of the titanium material results in the formation of titanium silicide or TiSix. In some embodiments, TiSix represents titanium silicide, where x is a number between 0.4 and 2.2. In some embodiments, TiSix represents one or more of Ti5Si3, TiSi2, TiSi, or a combination thereof.

[0025] In embodiments, the flow rates, temperatures, and pressures of the processing volume may be adjusted to values ​​sufficient for the desired reactions according to the present disclosure. In some embodiments, such as where the processing chamber 100 is configured for direct plasma applications (e.g., igniting a plasma in a region between the showerhead 165 and the semiconductor substrate 190), one or more desired gases (such as nitrogen (N2), hydrogen (H2), and / or argon (Ar)) may be directed from the gas panel 130 into the processing volume 101 via the first gas flow line 162, and one or more desired gases (such as argon (Ar)) may be directed to the processing volume 101 via the second gas flow line 163. In embodiments, the flow rates, temperatures, and pressures of the processing volume may be adjusted to values ​​sufficient for the desired reactions according to the present disclosure.

[0026] In an embodiment, the processing chamber 100 includes an RF electrode 180 sufficient for igniting a plasma in the processing volume 101 according to the present disclosure. In an embodiment, the RF electrode 180 may be coupled to one or more power supplies (one power supply is not shown) via one or more corresponding matching networks (matching networks are shown). The one or more power supplies may be capable of generating up to 3000 watts of RF energy at a frequency of about 350 kHz to about 60 MHz (such as, about 350 kHz, or about 13.56 MHz, or about 60 MHz). In an embodiment, about 65 watts to 150 watts of RF energy is applied to the remote plasma reaction in the processing volume 101. In some embodiments, the RF energy is about 120 watts to 140 watts or about 130 watts. In some embodiments, pulsed RF energy or RF in a continuous wave mode is applied. In some embodiments, the RF power is about 300 watts to about 500 watts, wherein the pulse frequency is about 10 kHz and the duty cycle is about 20%. In some embodiments, the processing chamber 100 may use capacitively coupled RF energy for plasma processing. For example, the processing chamber 100 may have a ceiling made of a dielectric material and a showerhead 165 that is at least partially conductive to provide an RF electrode (or a separate RF electrode may be provided). The showerhead 165 (or other RF electrode) may be coupled to one or more RF power sources (one RF power source is not shown) via one or more corresponding matching networks (matching networks are not shown). The one or more plasma sources may be capable of generating up to about 3,000 watts or, in some embodiments, up to about 5,000 watts of RF energy.

[0027] Figure 2 is a flow chart of a method 200 of selective deposition according to some embodiments of the present disclosure. FIG. 3A to FIG. 3B For a substrate (such as a semiconductor substrate 190) according to some embodiments of the present disclosure, Figure 2Illustrative cross-sectional views during various stages of a processing sequence of the present disclosure. The methods of the present disclosure may be used in a processing chamber configured for thermal deposition techniques such as chemical vapor deposition (CVD) or in a processing chamber configured for thermal deposition techniques such as chemical vapor deposition (CVD). Figure 1 The present invention relates to a process chamber in which the plasma is subjected to a pulse of 1 kHz and a duty cycle of 50%. In addition, conventional methods and apparatuses typically use a pulse frequency of 1 kHz and a duty cycle of 50%. However, when using such methods and apparatuses, particles may become overloaded on the substrate, which may result in dirty process chamber conditions. The inventors have discovered that by increasing the pulse frequency (e.g., from about 5 kHz to about 100 kHz, and in at least some embodiments from about 5 kHz to about 10 kHz) and decreasing the duty cycle (e.g., from about 10% to about 25%, and in at least some embodiments from about 20% to about 25%), the plasma behavior is changed from pulsed on / off to constantly on, and the particle count is significantly improved from overload to less than 50 counts.

[0028] In an embodiment, method 200 is performed as follows Figure 3A , which has a silicon surface 302 extending across the bottom of feature 351 and one or more dielectric surfaces such as dielectric surface 304. In an embodiment, semiconductor substrate 190 may include silicon material 301, such as crystalline silicon (e.g., Si <100> or Si <111> ), silicon germanium, doped or undoped polysilicon, doped or undoped silicon wafers, patterned or unpatterned wafers, silicon on insulator (SOI), and combinations thereof. In an embodiment, the semiconductor silicon material 301 may include or consist of the following materials, such as: crystalline silicon (e.g., Si <100> or Si <111> ), pure silicon, substantially pure silicon (having less than 1% or less than 0.5% impurities), or exposed silicon (such as pre-treated silicon in which the native oxide layer is removed). In embodiments, semiconductor substrate 190 may have various sizes, such as 200 mm, 300 mm, 450 mm, or other diameters for a circular substrate. Semiconductor substrate 190 may also be any polygonal, square, rectangular, curved, or otherwise non-circular workpiece, such as a polygonal glass substrate used to manufacture flat panel displays. Unless otherwise stated, the implementations and examples described herein are performed on a substrate (such as semiconductor substrate 190) having, for example, a 200 mm diameter substrate, a 300 mm diameter substrate, or a 450 mm diameter substrate.

[0029] In some embodiments, silicon material 301 is deposited via any suitable atomic layer deposition process or chemical layer deposition process. In some embodiments, silicon material 301 may include any suitable silicon material used in semiconductor device manufacturing. Figure 3A, a silicon oxide layer (not shown) may be on top of the silicon surface 302. The silicon oxide layer may be a native oxide layer or may be formed as the silicon surface 302 is exposed to oxygen (e.g., in air or water). In some embodiments, the silicon oxide layer may be problematic because the silicon oxide layer may be less selective to the titanium material than the exposed silicon surface. In some embodiments, the method 200 may include pre-treating the silicon surface 302 to form an exposed silicon surface. In some embodiments, the method includes contacting the silicon surface 302 with one or more etchants to form the exposed silicon surface 302. In some embodiments, the silicon oxide layer is removed before depositing the titanium material on top of the silicon surface 302 or directly on top of the silicon surface 302 to form an exposed silicon surface. Non-limiting examples of exposed silicon surface materials include substantially pure (e.g., substantially oxide-free) silicon and the like.

[0030] In an embodiment, the dielectric layer 305 including the dielectric surface 304 is different from the silicon material 301 including the silicon surface 302. In some embodiments, the dielectric layer 305 is deposited via any suitable atomic layer deposition process or chemical layer deposition process. In some embodiments, the dielectric layer 305 may include a low dielectric constant dielectric layer deposited on top of the silicon material 301. In some embodiments, the dielectric layer 305 may include any low dielectric constant dielectric material suitable for semiconductor device manufacturing, and combinations thereof. Non-limiting materials suitable as low dielectric constant dielectric materials may include silicon-containing materials, for example, such as silicon oxide (SiO2), silicon nitride, or silicon oxynitride (SiON), or combinations thereof, or combinations of layers thereof. In an embodiment, the low dielectric constant dielectric material may have a low dielectric constant value less than about 3.9 (e.g., about 2.5 to about 3.5). In some embodiments, the dielectric layer 305 may include hafnium oxide, such as HfO x In an embodiment, the dielectric layer 305 and the dielectric surface 304 include or consist of silicon oxide (SiO2), silicon nitride, silicon oxynitride (SiON), or a combination thereof.

[0031] The substrate may be pretreated as appropriate. For example, the dielectric layer 305 may be pretreated by contacting the dielectric layer 305 with silane alone or with silane in combination with an inert gas such as argon. In some embodiments, the dielectric layer 305 includes a nitrogen material such as silicon nitride, and the substrate may be preheated prior to depositing the titanium material layer. In some embodiments, during a method of selectively depositing a titanium material layer atop a substrate having a silicon surface and a dielectric surface such as silicon nitride, the substrate is preheated to a temperature of 200 to 800 degrees Celsius by contacting the substrate and the dielectric surface with a heated gas such as heated argon or hydrogen before forming a remote plasma reaction between titanium tetrachloride (TiCl4), hydrogen (H2), and argon (Ar) at a first temperature of 200 to 500 degrees Celsius in a region between a lid heater and a showerhead of a processing chamber. Reference Figure 1 In some embodiments, argon and hydrogen may flow through the first gas flow line 162 and be heated to preheat the substrate. In some embodiments, silane and argon may flow through the second gas flow line 163 while the substrate is preheated. In an embodiment, about 500 sccm to 3000 sccm of silane flows through the second gas flow line 163 to react with and / or cover the dielectric surface 304. In some embodiments, the dielectric surface is silicon nitride (SiN), and the silane contacts the dielectric surface in an amount sufficient to saturate the exposed surface of the dielectric surface 304. In an embodiment, the silane combines with the silicon in the silicon nitride layer of the dielectric surface 304, thereby further enhancing the selectivity of the titanium material to silicon. In some embodiments, the pretreatment including heating the substrate in the presence of silane further enhances the selectivity for silicon and away from silicon nitride. In some embodiments (such as, where the titanium material is titanium), the pretreatment enhances the selectivity to silicon to greater than 40:1, such as, 45:1. In some embodiments (such as where the titanium material is titanium silicide), the pretreatment enhances the selectivity to silicon to greater than 60:1, such as 68:1.

[0032] In some embodiments, method 200 includes preheating the substrate to a temperature above 200 degrees Celsius or between 200 degrees Celsius and 800 degrees Celsius, such as by preheating as described above. In some embodiments, such as where the dielectric surface is silicon nitride, the substrate may further be contacted with silane during pretreatment as described above.

[0033] In some embodiments, the present disclosure relates to a method of selectively depositing a titanium material layer on top of a substrate having a silicon surface and a dielectric surface (including silicon nitride), comprising: preheating the substrate by contacting the substrate with hydrogen and argon at a temperature above room temperature (such as a temperature of 200 degrees Celsius to 800 degrees Celsius) while contacting the substrate with argon and silane; then forming a remote plasma reaction between titanium tetrachloride (TiCl4), hydrogen (H2) and argon (Ar) in a region between a lid heater and a showerhead of a processing chamber at a temperature of 200 degrees Celsius to 800 degrees Celsius; and flowing the reaction products into the processing chamber to selectively form a titanium material layer on the silicon surface of the substrate. In some embodiments, silane and argon are supplied via a second gas flow line 163 to form a titanium material layer including or consisting of titanium silicide (TiSix). In an embodiment, a silane (SiH4) pre-soak enhances selectivity for remote plasma chemical vapor deposition (CVD) titanium and remote plasma CVD titanium silicide (TiSix) deposition processes. In an embodiment, the pre-treatment includes contacting the substrate with hydrogen and argon at a temperature above room temperature, such as a temperature of 200 degrees Celsius to 800 degrees Celsius, while contacting the substrate with argon and silane.

[0034] In an embodiment, the dielectric layer 305 may include one or more features 351, such as vias or trenches formed in the dielectric layer 305. The one or more features 351 may be formed by etching the dielectric layer 305 using any suitable etching process. In some embodiments, the one or more features 351 are defined by one or more sidewalls 314, openings 322, and upper corners 321. In some embodiments, the one or more features 351 may have a high aspect ratio, for example, an aspect ratio of about between about 5:1 and about 20:1. As used herein, aspect ratio is the ratio of the depth of a feature to the width of the feature. In an embodiment, the one or more features 351 have a width 309 less than or equal to 20 nanometers, less than or equal to 10 nanometers, or a width 309 between 5 nanometers and 10 nanometers.

[0035] Still refer to Figure 2In some embodiments, method 200 may begin at 202, where a plasma reaction between titanium tetrachloride (TiCl4), hydrogen (H2), and argon (Ar) is formed in a region between a lid heater and a showerhead of a processing chamber or between the showerhead and a substrate while providing RF power at a pulse frequency of about 5 kHz to about 100 kHz and a duty cycle of about 10% to about 20%. For example, method 200 may include forming a plasma reaction between titanium tetrachloride (TiCl4), hydrogen (H2), and argon (Ar) in a region between lid heater 131 and showerhead 165 of processing chamber 100, or forming a plasma reaction between titanium tetrachloride (TiCl4), hydrogen (H2), and argon (Ar) in a region between showerhead 165 and semiconductor substrate 190. In at least some embodiments, method 200 includes forming a plasma reaction between titanium tetrachloride (TiCl4), hydrogen (H2), and argon (Ar) in a region between lid heater 131 and showerhead 165. In at least some embodiments, at 202, the duration of forming the plasma reaction is about 750 seconds. In at least some embodiments, at 202, the processing chamber can be pressurized to about 3 Torr during the plasma reaction. In at least some embodiments, at 202, titanium tetrachloride (TiCl4) is provided at a flow rate of about 40 sccm during the plasma reaction, hydrogen (H2) can be provided at a flow rate of 20 sccm during the plasma reaction, and argon (Ar) can be provided at a flow rate of about 1.5k sccm during the plasma reaction. In at least some embodiments, at 202, the lid heater 131 can be maintained at a first temperature of about 200 degrees Celsius to about 800 degrees Celsius.

[0036] Next, at 204, method 200 includes flowing the reaction product into the processing chamber to selectively form a titanium material layer on the silicon surface of the substrate. For example, the reaction product is formed to form a titanium material layer 350 on a substrate (such as semiconductor substrate 190) inside the processing chamber so that the titanium material layer 350 is selectively deposited atop the silicon surface 302 of the substrate. In an embodiment, the dielectric surface 304 inhibits the deposition of the titanium material layer 350 atop the dielectric surface 304. In an embodiment, the remote plasma reaction reacts titanium tetrachloride (TiCl4), hydrogen (H2), and argon (Ar) at a first temperature of 200 degrees Celsius to 800 degrees Celsius. In some embodiments, the substrate (including semiconductor substrate 190) includes a feature (such as a high aspect ratio feature), wherein the silicon surface 302 is disposed at a bottom 307 of the high aspect ratio feature, and the dielectric surface 304 is disposed on one or more sidewalls 314 of the high aspect ratio feature (such as one or more features 351). In some embodiments, the first temperature may be about 550 degrees Celsius, or less than 500 degrees Celsius. In some embodiments, about 65 watts of RF energy is applied to the remote plasma reaction. In an embodiment, the titanium material layer is deposited to a predetermined thickness, such as about 10 angstroms to about 100 angstroms, or about 100 angstroms to about 500 angstroms. In some embodiments, the titanium material layer 350 includes titanium, titanium silicide, or substantially pure titanium.

[0037] In some embodiments, the method 200 further includes adding a silane compound (such as silane, hydrogen, and argon) to the showerhead (such as Figure 1 The showerhead 165 in the embodiment is used to contact the remote plasma reaction. In an embodiment, the titanium material layer 350 includes or consists of titanium silicide. In some embodiments, the titanium silicide is characterized as TiSix, where x is a number in the range of 0.4 to 2.2.

[0038] refer to Figure 2 In some embodiments, method 200 may optionally include post-deposition processing of the titanium material layer to further enhance selectivity and promote robust formation of the semiconductor element. Therefore, post-processing of the titanium material layer is included in the present disclosure. In some embodiments, post-processing of the titanium material layer after deposition will include a pre-selected processing sequence depending on the composition of the deposited titanium material layer, for example, whether the titanium material layer is the result of remote plasma chemical vapor (CVD) deposition of titanium or remote plasma CVD deposition of titanium silicide.

[0039] The inventors have observed benefits of post-processing the titanium material layer after its deposition. For example, the inventors have observed that residues or reaction byproducts on the showerhead, such as titanium chloride (TiClx or TiClx, where x is a number in the range of 1 to 3, or where x=3), can lead to the formation of titanium nitride (TiN) and problematically deposit TiN films atop silicon surfaces or exposed silicon surfaces and dielectric surfaces, such as silicon nitride dielectric surfaces, which degrade selectivity. The inventors have discovered that post-processing after remote plasma CVD titanium or remote plasma CVD titanium silicide deposition and before any downstream nitridation can passivate byproducts, such as titanium chloride deposited or adhered to the showerhead, and reduce problematic memory effects to less than three angstroms.

[0040] In some embodiments, a post-deposition treatment is optionally performed after the remote plasma CVD deposition of titanium. The inventors have observed that in the case where the remote plasma reaction reacts titanium tetrachloride (TiCl4), hydrogen (H2) and argon (Ar) provided via the first gas flow line 162 and argon (Ar) provided via the second gas flow line 163 at a first temperature of 200 degrees Celsius to 800 degrees Celsius, titanium chloride (TiClx) and hydrogen radicals may accumulate between the showerhead and the substrate, thereby problematically causing titanium chloride (TiClx) to adhere to the showerhead surface and / or the top surface of the substrate. After the titanium chloride (TiClx) is formed, the titanium chloride (TiClx) may contact silane provided via the second gas flow line 163, which covers the titanium chloride (TiClx) and forms titanium silicide (TiSix) on the showerhead at a temperature greater than 400 degrees Celsius (e.g., 450 degrees Celsius to 500 degrees Celsius) or at a temperature between 200 degrees Celsius and 800 degrees Celsius. In some embodiments, the showerhead is at a temperature of 200 degrees Celsius to 800 degrees Celsius or about 500 degrees Celsius, heated by radiant energy from a lid heater at a temperature of 200 degrees Celsius to 800 degrees Celsius or about 550 degrees Celsius. In an embodiment, 0.5 liters to 3 liters of a silane compound, such as silane, is added. In an embodiment, the silane compound or silane flows through the second gas flow line 163 at 500 seem to 3000 seem. In some post-processing embodiments, after forming the titanium silicide (TiSix), the silane compound or silane is purged from the processing chamber by performing a hydrogen soak and / or a remote plasma soak, wherein hydrogen radicals react with the titanium silicide (TiSix) to form a strong titanium silicide (TiSix) composition that does not flake off the showerhead and / or flake onto the substrate. In an embodiment, titanium silicide (TiSix) has superior adhesion and strong bonding compared to titanium chloride (TiClx). In some embodiments, remote plasma is performed by flowing hydrogen and argon through the first gas flow line 162 while simultaneously flowing argon through the second gas flow line 163. In an embodiment, the processing chamber is grounded so that the remote plasma is formed between the lid heater and the showerhead. In some embodiments, after flowing the reaction products into the processing chamber to selectively form a titanium material layer on the silicon surface of the substrate: post-treating the titanium material layer at a temperature greater than 200 degrees Celsius or at a temperature between 200 degrees Celsius and 800 degrees Celsius. In some embodiments in which the titanium material layer includes or consists of titanium, the post-treating (post-treatment) includes contacting the titanium with one or more of silane and hydrogen or hydrogen radicals.

[0041] In some embodiments, a post-deposition treatment is optionally performed after remote plasma CVD deposition of titanium silicide. The inventors have observed that when a remote plasma reaction reacts titanium tetrachloride (TiCl4), hydrogen (H2) and argon (Ar) provided via the first gas flow line 162 and argon (Ar) and silane provided via the second gas flow line 163 at a first temperature of 200 degrees Celsius to 800 degrees Celsius, titanium chloride (TiClx), hydrogen radicals and silane compounds (such as silane) react between the showerhead and the substrate to form titanium silicide (TiSix) on the showerhead surface and / or the top surface of the substrate. Including silane compounds (such as silane) in the deposition reactants can form problematic titanium silicide (TiSix). After forming the titanium silicide (TiSix), silane is purged from the processing chamber by performing a hydrogen soak and / or a remote plasma soak, wherein hydrogen radicals react with the titanium silicide (TiSix) to form a solid titanium silicide (TiSix) composition that does not flake onto the substrate or flake off the showerhead. In embodiments, the titanium silicide (TiSix) has excellent adhesion and strong bonding. In some titanium silicide remote plasma CVD deposition embodiments, a silane soak treatment sequence is not performed because, in embodiments, the deposition chemistry includes silane. In some embodiments, the remote plasma is performed by flowing hydrogen and argon through the first gas flow line 162 while simultaneously flowing argon through the second gas flow line 163. In embodiments, the processing chamber is grounded so that the remote plasma is formed between the heater cover and the showerhead. In some embodiments, the titanium material layer to be post-processed includes or consists of titanium silicide, and the post-processing includes contacting the titanium silicide with one or more of hydrogen or hydrogen radicals, such as in an amount sufficient to make the titanium silicide solid.

[0042] In some embodiments, the method 200 may further include: Figure 1 between the showerhead 165 in the processing chamber (such as, Figure 1A direct plasma reaction between nitrogen (N2), hydrogen (H2) and argon (Ar) is formed inside a processing chamber 100 in the semiconductor substrate 190 to form a titanium nitride capping layer 370 on or in the titanium material layer 350 on top of the silicon surface 302 of the semiconductor substrate 190. In some embodiments, a direct plasma nitrogen and hydrogen reaction is provided to form the titanium nitride capping layer 370. In some embodiments, the direct plasma reaction is performed after the titanium material layer 350 is post-treated as described above. In some embodiments, nitrogen is included in the direct plasma reaction in an amount of 4 to 8 standard liters per minute (slpm) or about 6 slpm. In some embodiments, hydrogen is provided to the direct plasma reaction in an amount of 0.5 slpm to 2 slpm or about 1 slpm. In an embodiment, argon is provided to the direct plasma reaction in an amount of 2 slpm to 5 slpm (such as, 3.75 slpm). In an embodiment, the processing chamber has a pressure of about 1 torr to 8 torr (such as, 3 torr) during the direct plasma reaction. In an embodiment, RF power is applied at about 300 Watts to about 500 Watts (and 500 Watts in at least some embodiments) during the direct plasma reaction. In some embodiments, the wafer temperature is maintained at a temperature of 200 degrees Celsius to 800 degrees Celsius (such as, about 425 degrees Celsius) during the direct plasma reaction. In some embodiments, the lid heater is heated to a temperature of 200 degrees Celsius to 800 degrees Celsius (such as, about 550 degrees Celsius) during the direct plasma reaction. In some embodiments, the susceptor temperature is maintained at a temperature of 200 degrees Celsius to 800 degrees Celsius or about 450 degrees Celsius during the direct plasma reaction.

[0043] In some embodiments, the nitridation process sequence or the direct plasma reaction provides nitrogen at a flow rate of about 0.1 slpm to 6 slpm, and hydrogen is provided in an amount of 0.1 slpm to 6 slpm. In an embodiment, the pressure of the process chamber is maintained at 1 Torr to 15 Torr, such as 3 Torr, during the direct plasma reaction. In an embodiment, the RF power is applied at about 100 Watts to 1000 Watts during the direct plasma reaction.

[0044] 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.

Claims

1. A method for processing a substrate, comprising: forming a plasma reaction between titanium tetrachloride (TiCl4), hydrogen (H2), and argon (Ar) in a region between a lid heater and a showerhead of a processing chamber or between the showerhead and a substrate while providing RF power at a pulse frequency of about 5 kHz to about 100 kHz and a duty cycle of about 10% to about 25%; as well as The reaction product is flowed into the processing chamber to selectively form a titanium material layer on the silicon surface of the substrate.

2. The method of claim 1, wherein the pulse frequency is about 5 kHz to about 10 kHz when forming the plasma reaction.

3. The method of claim 1, wherein the duty cycle is about 20% to about 25% when forming the plasma reaction.

4. The method of claim 1, wherein the RF power is about 300 Watts to about 500 Watts when forming the plasma reaction.

5. The method of claim 1, wherein the RF power is provided at about 350 kHz when forming the plasma reaction.

6. The method of claim 1, wherein the duration of forming the plasma reaction is about 750 seconds.

7. The method of claim 1, wherein the processing chamber is pressurized to about 3 Torr during the plasma reaction.

8. The method of claim 1, wherein the titanium tetrachloride (TiCl4) is provided at a flow rate of about 40 sccm during the plasma reaction.

9. The method of claim 1, wherein the hydrogen (H2) is provided at a flow rate of 20 sccm during the plasma reaction.

10. The method of claim 1, wherein the argon (Ar) is provided at a flow rate of about 1.5 ksccm during the plasma reaction.

11. The method of claim 1 , wherein the substrate comprises high aspect ratio features, and Wherein the silicon surface is disposed at a bottom of the high aspect ratio feature and a dielectric surface is disposed on one or more sidewalls of the high aspect ratio feature.

12. The method of claim 11, wherein the dielectric surface comprises silicon oxide or silicon nitride.

13. The method of claim 1, wherein the titanium material layer is deposited to about 10 angstroms to about 100 angstroms.

14. The method of claim 1, wherein the titanium material layer comprises titanium, titanium silicide, or substantially pure titanium.

15. The method of claim 1, further comprising: Silane, disilane, hydrogen and argon are added to the showerhead to contact the plasma reaction.

16. A non-transitory computer readable storage medium having instructions stored thereon, which when executed by a processor perform a method for processing a substrate, the method comprising: forming a plasma reaction between titanium tetrachloride (TiCl4), hydrogen (H2), and argon (Ar) in a region between a lid heater and a showerhead of a processing chamber or between the showerhead and a substrate while providing RF power at a pulse frequency of about 5 kHz to about 100 kHz and a duty cycle of about 10% to about 25%; as well as The reaction product is flowed into the processing chamber to selectively form a titanium material layer on the silicon surface of the substrate.

17. The non-transitory computer readable storage medium of claim 16, wherein when forming the plasma reaction, the pulse frequency is about 5 kHz to about 10 kHz.

18. The non-transitory computer readable storage medium of claim 16, wherein the duty cycle is about 20% to about 25% when forming the plasma reaction.

19. The non-transitory computer readable storage medium of claim 16, wherein the RF power is about 300 Watts to about 500 Watts when forming the plasma reaction.

20. A processing system for processing a substrate, comprising: a processing chamber defining a processing volume disposed in a region between the lid heater and the showerhead or in a region between the showerhead and the substrate; RF power supply; a gas panel connected to the cap heater and the showerhead; as well as The controller is configured as: forming a plasma reaction between titanium tetrachloride (TiCl4), hydrogen (H2) and argon (Ar) in the region between the cover heater and the showerhead or between the showerhead and the substrate while providing RF power at a pulse frequency of about 5 kHz to about 100 kHz and a duty cycle of about 10% to about 25%; as well as The reaction product is flowed into the processing chamber to selectively form a titanium material layer on the silicon surface of the substrate.

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