KR102392620B1 - Low vapor pressure aerosol-assisted cvd - Google Patents

Abstract

Systems and methods for processing films on a surface of a substrate are described. Systems possess aerosol generators that form droplets from condensed matter (liquid or solid) of one or more precursors. A carrier gas flows through the condensed material and pushes the droplets toward the substrate disposed in the substrate processing region. An inline pump coupled to the aerosol generator may also be used to push the droplets towards the substrate. A direct current (DC) electric field is applied between two conductive plates configured to pass droplets therebetween. The size of the droplets is preferably reduced by application of a DC electric field. After passing through the DC electric field, the droplets are passed into the substrate processing region and chemically react with the substrate to deposit or etch films.

Description

LOW VAPOR PRESSURE AEROSOL-ASSISTED CVD

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a portion of U.S. Provisional Patent Application Serial No. 15/045,081, filed February 16, 2016, which claims priority to U.S. Provisional Patent Application Serial No. 62/255,644, filed November 16, 2015 continue to apply The disclosures of Nos. 15/045,081 and 62/255,644 are hereby incorporated by reference in their entirety for all purposes.

Field

[0002] Embodiments described herein relate to chemical vapor deposition using low vapor pressure precursors.

[0003] Forming films on a substrate by a chemical reaction of gases is one of the major steps in the fabrication of modern semiconductor devices. These deposition processes include chemical vapor deposition (CVD), as well as plasma enhanced chemical vapor deposition (PECVD) using plasma in combination with conventional CVD techniques. CVD and PECVD dielectric layers can be used as different layers in semiconductor devices. For example, dielectric layers may be used as intermetal dielectric layers between conductive lines or interconnects in a device. Alternatively, dielectric layers may be used as barrier layers, etch stops, or spacers, as well as other layers.

Chemical precursors were introduced into a substrate processing region of a substrate processing chamber. A substrate is positioned within a substrate processing region, and one or more precursors may be introduced into the substrate processing region to deposit a film. Liquid precursors may be used by “bubbling” a carrier gas through the liquid to transport the vapor into the substrate processing region. The effectiveness of this technique depends on the vapor pressure of the liquid. The temperature of the liquid may be increased to increase the vapor pressure. An ultrasonic generator has also been used to generate droplets, to increase delivery of precursors to the substrate processing region, but droplet size can adversely affect deposition uniformity and gapfill capabilities.

To expand the available applications that can utilize low vapor pressure precursors, methods for reducing droplet sizes in aerosol-assisted CVD are needed.

Systems and methods are described for processing films on a surface of a substrate. Systems have aerosol generators that form droplets from an aggregated material (liquid or solid) of one or more precursors. A carrier gas flows through the condensed material and pushes the droplets toward the substrate disposed in the substrate processing region. An inline mechanical pump coupled to the aerosol generator may also be used to push the droplets towards the substrate. A direct current (DC) electric field is applied between two conductive plates configured to pass droplets therebetween. The size of the droplets is preferably reduced by application of a DC electric field. After passing through the DC electric field, the droplets pass into the substrate processing region and chemically react with the substrate to deposit or etch films.

[0007] Embodiments disclosed herein include an apparatus for forming a self-assembled monolayer on a substrate. The apparatus includes a heated carrier gas supply. The apparatus further comprises an aerosol generator configured to receive the heated carrier gas from the heated carrier gas supply and configured to generate aerosol droplets from the aggregated material precursor. The device further comprises a precursor conduit configured to receive the aerosol droplets. The apparatus further includes a DC power supply. The device further includes a top electrode and a bottom electrode. The top and bottom electrodes are parallel and define an electrical gap configured to receive the aerosol droplets. The top electrode and bottom electrode are biased with a differential voltage from the DC power supply via vacuum electrical feedthroughs. A differential voltage is applied between the top and bottom electrodes to reduce the size of the aerosol droplets. The apparatus further includes a substrate pedestal disposed within a substrate processing region within the chamber. The substrate pedestal is configured to support the substrate during formation of the self-assembled monolayer.

[0008] The differential voltage may be selected to form an electric field having a magnitude of 500 V/cm to 20,000 V/cm. The differential voltage may be between 100 volts and 2 kilovolts. The aerosol droplets may have a diameter between 3 nm and 75 nm.

[0009] Embodiments disclosed herein include a substrate processing apparatus. The substrate processing apparatus includes a substrate pedestal disposed within a substrate processing region within the substrate processing apparatus. The substrate pedestal is configured to support the substrate during processing of the film. The substrate processing apparatus further includes a carrier gas supply. The substrate processing apparatus further comprises an aerosol generator configured to receive a carrier gas from the carrier gas supply and configured to generate aerosol droplets from the liquid precursor. The substrate processing apparatus further includes a heater for heating the carrier gas between the carrier gas supply and the aerosol generator. The substrate processing apparatus further includes a piezoelectric transducer attached to the aerosol generator to facilitate generation of the aerosol droplets. The substrate processing apparatus further includes a precursor conduit configured to receive the aerosol droplets. The substrate processing apparatus further includes a DC power supply. The substrate processing apparatus further includes a first electrode and a second electrode. The first electrode and the second electrode are parallel to each other and separated by a gap. The gap is configured to receive the aerosol droplets and receive a voltage through the vacuum electrical feedthroughs from the DC power supply. The voltage is applied between the first electrode and the second electrode to reduce the size of the aerosol droplets to a size of 3 nm to 75 nm, and to maintain the size of the aerosol droplets, until the aerosol droplets reach the substrate. is authorized to

[0010] The liquid precursor is, octylphosphonic acid (CH ₃ (CH ₂ ) ₆ CH ₂ -P(O)(OH) ₂ ), perfluorooctylphosphonic acid (CF ₃ (CF ₂ ) ₅ CH ₂ - CH ₂ -P(O)(OH) ₂ ), octadecylphosphonic acid (CH ₃ (CH ₂ ) ₁₆ CH ₂ -P(O)(OH) ₂ ), decyl phosphonic acid, mesityl phosphonic acid, one or more of cyclohexyl phosphonic acid, hexyl phosphonic acid, or butyl phosphonic acid. The first electrode and the second electrode may be horizontal. The substrate may be parallel to both the first electrode and the second electrode. The substrate may be disposed between the first electrode and the second electrode. The piezoelectric transducer may be in direct contact with the liquid precursor. Liquid precursors can be formed by dissolving solid precursors in a solvent. The substrate may be perpendicular to both the first electrode and the second electrode. The substrate pedestal may be an electrical insulator.

[0011] Embodiments disclosed herein include substrate processing chambers for forming a film on a substrate. The substrate processing chambers include a carrier gas supply. The substrate processing chambers further include an aerosol generator configured to receive the heated carrier gas from the heated carrier gas supply and configured to generate aerosol droplets from the aggregated material precursor. The substrate processing chambers further include a precursor conduit configured to receive the aerosol droplets. The substrate processing chambers further include a DC power supply. The substrate processing chambers further include a first electrode and a second electrode configured to receive a DC voltage from a DC power supply. The first electrode and the second electrode are parallel and form a gap between the first electrode and the second electrode. A DC voltage is applied between the first and second electrodes to reduce the size of the aerosol droplets. A DC voltage applied between the first electrode and the second electrode forms an electric field that is pointed from the first electrode directly towards the substrate and directly towards the second electrode. The substrate processing chambers further include a substrate pedestal disposed within a substrate processing region within the chamber. The substrate pedestal is configured to support the substrate during processing of the film.

[0012] The gap may be configured to receive aerosol droplets directly from the precursor conduit without the aerosol droplets passing through the first electrode or the second electrode. The gap may be configured to receive aerosol droplets through one or more openings in the first electrode or the second electrode. The substrate pedestal may include a carbon block.

[0013] Embodiments of the present invention include methods of forming a layer on a substrate. The methods include placing a substrate within a substrate processing region of a substrate processing chamber. The methods further include placing the liquid precursor within the aerosol generator. The methods further include flowing a carrier gas into the aerosol generator to generate the aerosol droplets. The methods further include applying an electric field to the aerosol droplets. The methods further include flowing the aerosol droplets into the substrate processing region. The methods further include forming a layer on the substrate from the aerosol droplets.

[0014] The layer may be either a II-VI or III-V semiconductor. The layer may be one of boron nitride, aluminum nitride, gallium arsenide, gallium phosphorus, indium arsenide, or indium antimonide. The layer may be a metal-oxide and may be composed of oxygen and metal elements. The electric field may be a DC electric field with the electric field pointed towards the substrate. The methods may further include flowing a second precursor into the substrate processing region to form a monolayer on the layer. The electron temperature in the substrate processing region during layer formation may be less than 0.5 eV.

[0015] Embodiments of the present invention include methods of processing a layer on a substrate. The methods include placing a substrate within a substrate processing region of a substrate processing chamber. The methods further include dissolving the solid precursor in a solvent to form a precursor solution in the aerosol generator. The methods further include flowing a carrier gas into the aerosol generator to generate the aerosol droplets. The methods further include applying an electric field to the aerosol droplets. The methods further include flowing the aerosol droplets into the substrate processing region. The methods further include etching the layer on the substrate by chemical reaction with the aerosol droplets.

[0016] A layer may consist of only two elements. The layer may be composed of a group III element and a group V element. The layer may be composed of a group II element and a group VI element. The methods may further include flowing a second precursor into the substrate processing region to remove one monolayer from the layer. The electric field may be a DC electric field with the electric field pointed towards the substrate. The electric field may have a size of 500 V/cm to 20,000 V/cm. The aerosol droplets may have a diameter between 3 nm and 75 nm. The electron temperature in the substrate processing region during etching the layer may be less than 0.5 eV.

[0017] Additional embodiments and features are set forth in part in the description that follows, some may be learned by practice of the disclosed embodiments, or will become apparent to those skilled in the art upon review of this specification. The features and advantages of the disclosed embodiments may be realized and attained by means of the instrumentalities, combinations, and methods described herein.

[0018] A further understanding of the nature and advantages of the disclosed embodiments may be realized by reference to the remaining portions of this specification and reference to the drawings.
1 is a flowchart of a film formation process in accordance with embodiments;
2 is a flowchart of a film formation process in accordance with embodiments;
3A is a side view of a patterned substrate after selective deposition of a self-assembled monolayer, in accordance with embodiments;
[0022] FIG. 3B is a side view of a patterned substrate after selective deposition using a self-assembled monolayer, in accordance with embodiments;
[0023] FIG. 3C is a side view of a patterned substrate after removal of a self-assembled monolayer, in accordance with embodiments.
[0024] FIG. 3D is a side view of a patterned substrate after selective deposition of a self-assembled monolayer, not using embodiments disclosed herein;
4 is a chart of contact angles for materials with and without self-assembled monolayers, according to embodiments.
5A shows a schematic cross-sectional view of a substrate processing chamber in accordance with embodiments;
5B shows a schematic cross-sectional view of a substrate processing chamber in accordance with embodiments;
5C shows a schematic cross-sectional view of a substrate processing chamber in accordance with embodiments;
[0029] FIG. 6 shows a schematic contrast of deposition techniques including methods according to embodiments;
7 shows a top view of an exemplary substrate processing system in accordance with embodiments;
In the accompanying drawings, similar components and/or features may have the same reference numerals. Additionally, various components of the same type may be distinguished by having a reference sign followed by a dash, and a second sign that distinguishes between similar components. In the case where only the first reference sign is used in the specification, the description is applicable to any one of the similar components having the same first reference sign, irrespective of the second reference sign.

Systems and methods are described for processing films on a surface of a substrate. Systems have aerosol generators that form droplets from an aggregated material (liquid or solid) of one or more precursors. A carrier gas flows through the condensed material and pushes the droplets toward a substrate disposed in the substrate processing region. An inline mechanical pump coupled to the aerosol generator may also be used to push the droplets towards the substrate. A direct current (DC) electric field is applied between two conductive plates configured to pass droplets therebetween. The size of the droplets is preferably reduced by application of a DC electric field. After passing through the DC electric field, the droplets pass into the substrate processing region and chemically react with the substrate to deposit or etch films.

[0033] A need exists to expand the suite of available chemical precursors that can be used, for example, in CVD, atomic layer etching (ALEt), and atomic layer deposition (ALD) chambers. Low vapor pressure solid precursors and high boiling point liquid precursors have been difficult to deliver in the vapor phase into CVD, ALEt, or ALD chambers. This has limited the use of precursors for thin film material deposition. Improving the delivery of solid and low vapor pressure liquids into processing chambers can improve deposition, in particular, of films containing more than one element. Self-assembled monolayers (SAM) may particularly benefit from the use of low vapor pressure precursors. Semiconductor film formation applications benefit from dry deposition processes (vapor phase) compared to liquid deposition processes.

[0034] Embodiments described herein may involve a liquid precursor and/or a solid precursor having a low vapor pressure. Liquids and solids (or a combination) may generally be described as agglomerated material. According to embodiments, the condensed material consists of atoms/molecules that are continuously under the influence of forces imparted by neighboring atoms/molecules and have essentially no mean free path, or mean free path. It can be defined as a material that does not have In embodiments, a solid precursor having a low vapor pressure may be dissolved in a single solvent, or a mixture of compatible solvents, the combination may be referred to as an agglomerated material. An aerosol is formed from the agglomerated material and may be formed using an ultrasonic humidifier. An ultrasonic humidifier may have a piezoelectric transducer that may be operated at one or more frequencies. An ultrasonic humidifier may use a carrier gas such as nitrogen (N ₂ ) or argon (Ar) to generate aerosol droplets that are transported into the reaction chamber (substrate processing region). The carrier gas may be inert and may not form covalent chemical bonds with the cohesive material or the substrate. An inline mechanical pump coupled to the aerosol generator may also be used to push the droplets towards the substrate.

[0035] The aerosol droplets may pass through a heated conduit(s) to prevent agglomeration and promote reaction with the substrate after the aerosol droplets enter the substrate processing region. A substrate processing region is a vacuum chamber that resides within the substrate processing chamber and is evacuated to atmospheric gases prior to delivery of precursors into the substrate processing region. In embodiments, the substrate processing region is sealed from the outside atmosphere and may be operated at a pressure much lower than atmospheric pressure to evacuate atmospheric gases. Agglomerated material precursors do not need to be volatilized to create aerosol droplets. The aggregated material precursors may be soluble in a solvent, or mixture of solvents, from which aerosol droplets are generated. As a result of the embodiments described herein, a wider range of precursors can now be used as volatility is no longer required. The substrate processing chamber may also be configured to have two electrodes capable of generating an electric field. The electric field has been found to preferably reduce the size of the aerosol droplets or maintain the small size of the aerosol droplets.

[0036] To better understand and appreciate the embodiments described herein, reference is now made to FIGS. 1 and 2 , which are flowcharts of film formation processes 101 and 201 in accordance with embodiments. At the same time, reference will be made to FIG. 5A , which includes a schematic cross-sectional view of a substrate processing chamber 1001 in accordance with embodiments. Any of the substrate processing chambers of FIGS. 5A , 5B , 5C , or combinations of elements thereof may be used to perform the processes (eg, 101 or 102 ) described herein. In process 101 , in operation 110 , a substrate 1013 is transferred into a substrate processing region of a substrate processing chamber 1001 . The substrate 1013 is supported by a substrate pedestal 1014 , which may be resistively heated and/or cooled by passing a thermally controlled liquid through the substrate pedestal 1014 . can be A portion of the substrate pedestal and all of the substrate 1013 are shown within the substrate processing region. Additionally, the substrate processing region is defined by a quartz housing 1016 and a quartz baffle 1012 that may be included to beneficially reduce the temperature of the chamber body 1006 during film formation.

In operation 120 , a solid precursor is dissolved in a solvent and placed in an aerosol generator 1003 - 1 having a piezoelectric transducer 1004 - 1 . In operation 130 , a carrier gas is heated in the heated carrier gas supply 1002 and flowed into the aerosol generator 1003 - 1 . The piezoelectric transducer 1004 - 1 is vibrated by applying an oscillating voltage to the top and bottom of the transducer, and aerosol droplets are generated from the precursor solution in the aerosol generator 1003 - 1 (operation 140 ). Also, in operation 140 , aerosol droplets flow through precursor conduit 1015 - 1 and enter substrate processing chamber 1001 through top lid 1005 . Aerosol droplets also flow through the top electrode 1009 before entering the substrate processing region housing the substrate 1013 , and then through the bottom electrode 1010 . While the aerosol droplets pass between the two electrodes, a DC electric field is applied between the top electrode 1009 and the bottom electrode 1010 (act 150 ). An electric field is applied to the electric field region 1011 and is pointed from the top electrode 1009 towards the bottom electrode 1010 . The insulator 1008 is configured to maintain electrical isolation between the top electrode 1009 and the bottom electrode 1010 . In embodiments, the chamber body 1006 and the top lid 1005 may also be electrically isolated from one or both of the top electrode 1009 and the bottom electrode 1010 . A DC voltage differential is created within the DC power supply 1007 and passed through vacuum compatible electrical feedthroughs into the substrate processing region. In embodiments, the small size of the aerosol droplets is reduced or maintained through application of a DC electric field perpendicular to the major plane of the substrate 1013 . The top electrode 1009 and the bottom electrode 1010 have apertures that allow aerosol droplets to pass through both, but are otherwise planar and each parallel to the major plane of the substrate 1013 . The substrate may also be electrically biased during deposition. At operation 160 , a film is deposited on the substrate 1013 from the aerosol droplets, and at operation 170 , the substrate is removed from the substrate processing region.

Aerosol generators 1003 may further be located proximate the substrate processing chamber 100 to maintain small aerosol droplet sizes. The volume within the aerosol generators 1003 may be approximately proportional to the area of the substrate to be processed. For example, to generate aerosol droplets for a 300 mm substrate, a one liter aerosol generator 1003 may be used. A mass flow controller may be used to control the flow rate of aerosol droplets in the precursor conduit 1015 - 1 towards the substrate processing chamber 1001 . The precursor conduit 1015 - 1 may include activated charcoal to maintain an elevated temperature (above room temperature) of the aerosol droplets, which also aids in maintaining small aerosol droplet sizes.

A solid precursor was used for the film formation process 101 . In embodiments, a solid or liquid precursor may have been used, with a solid precursor being illustrated to demonstrate the effectiveness of the technique in receiving low vapor pressure precursors. In the examples that follow, a liquid precursor is used, but in embodiments, a solid precursor may be substituted for the liquid precursor. At operation 210 , a substrate is disposed within a substrate processing region.

A liquid precursor is disposed in an aerosol generator 1003 - 2 having an embedded transducer 1004 - 2 . A carrier gas is heated in the heated carrier gas supply 1002 and flows into the aerosol generator 1003 - 2 . The transducer 1004-2 is vibrated by applying an oscillating voltage to the top and bottom of the transducer, and aerosol droplets are generated from the precursor solution in the aerosol generator 1003-2 (act 220). According to embodiments, the liquid precursor may also be dissolved in a solvent or a compatible combination of solvents, as is the case for the solid precursor of the first example. The aerosol droplets then flow through the precursor conduit 1015 - 2 and enter the substrate processing chamber 1001 through the top lid 1005 . The aerosol droplets then flow through the top electrode 1009 and through the bottom electrode 1010 before entering the substrate processing region housing the substrate 1013 in operation 230 . Before entering the substrate processing region, a DC electric field is applied between the top electrode 1009 and the bottom electrode 1010 while the aerosol droplets pass between the two electrodes. An electric field is applied to the electric field region 1011 and is pointed from the top electrode 1009 towards the bottom electrode 1010 . The insulator 1008 is configured to maintain electrical isolation between the top electrode 1009 and the bottom electrode 1010 . A DC voltage differential is created within the DC power supply 1007 and passed through vacuum compatible electrical feedthroughs into the substrate processing region. In embodiments, the small size of the aerosol droplets is reduced or maintained through application of a DC electric field perpendicular to the major plane of the substrate 1013 . The top electrode 1009 and the bottom electrode 1010 have one or more apertures that allow aerosol droplets to pass through both, but are otherwise flat, each parallel to the major plane of the substrate 1013 . . In embodiments, the pedestal may be electrically biased with respect to the chamber body 1006 , the top electrode 1009 , and/or the bottom electrode 1010 .

A thin film is deposited on the substrate 1013 from small aerosol droplets. The substrate processing zone may be evacuated to remove unreacted aerosol droplets and reaction byproducts. Thereafter, in operation 250 , a second precursor having distinct chemical properties is flowed into the substrate processing region (operation 240 ) to complete the formation of the “atomic” layer deposited film (ALD). If the target thickness is not achieved, the process may be repeated (act 260). Once the target thickness is achieved, in operation 270 , the substrate is removed from the substrate processing region. Generally speaking, the precursors may be delivered to the substrate processing region in a sequential and alternating manner, as in this example, or according to embodiments, the precursors may enter the reactor simultaneously. In embodiments, the precursors may be combined with each other prior to entering the substrate processing region.

[0042] Benefits of the equipment and processes described herein may relate to a reduction in processing time. Film formation using low vapor precursors has been found to often require hours and even tens of hours to obtain a beneficial film thickness. The hardware and techniques described herein may be used to reduce film etch/form times by a hundred fold or more to a thousand fold or more, depending on embodiments. In embodiments, the etch/deposition times may be between 5 seconds and 5 minutes, or between 15 seconds and 2 minutes. The vapor etching or vapor deposition techniques described herein are “dry” processes in which reactions are dominated by gas-surface chemical reactions. Some prior art processes involve immersing the patterned substrate in a liquid solution containing a low vapor pressure precursor to obtain desirable etch or deposition rates. Herein, the precursors are delivered to the substrate in the gas-phase, and thus the processes may be described as dry processes. The dry processes described herein avoid damage that may occur to small linewidth patterned substrates as a result of surface tension of liquid processing. A benefit of dry processes and equipment includes achieving high etch/deposition rates while avoiding pattern collapse.

[0043] In all embodiments described herein, the precursors are on an aggregated material, which may include dissolved in a solvent. In embodiments, the vapor pressure of the aggregated material precursor, prior to dissolution (or if no solvent is used), may be zero, may be measurably low, may be less than 10 Torr, or may be less than 20 Torr. or less than 30 Torr. According to embodiments, the vapor pressure of the solution containing the aggregated material precursor and a suitable solvent may be less than 10 Torr, less than 30 Torr, or less than 50 Torr, after dissolution. Exemplary aggregated material precursors will be presented after introducing the underlying deposition application.

[0044] An exemplary deposition application that may benefit from the hardware and techniques described herein is the formation of self-assembled monolayers, which may involve the use of low vapor pressure liquid precursors. A benefit of the deposition processes described herein is an extremely conformal deposition rate on finely and intricately patterned substrates. Deep gaps, trenches, or vias often exhibit a higher deposition rate near their opening compared to deep portions within the trench, especially when droplet sizes are large compared to feature sizes or linewidths. According to embodiments, the methods described herein may be used to deposit conformal films having a uniform or relatively uniform thickness of 0.5 nm to 20 nm, 1 nm to 10 nm, or 2 nm to 5 nm. there is. Alternatively, the methods may be used to etch with a uniform etch rate despite complex patterning on a patterned substrate. In embodiments, the widths and depths of the via or trench (features) may be between 3 nm and 20 nm, or between 5 nm and 10 nm. Although all parameters described herein may apply for both etching and deposition, illustrative examples describe deposition processes. In embodiments, the width of the via or trench (in the narrower dimension) may be less than 30 nm, less than 20 nm, or less than 10 nm. Here, the depths are measured from the top of the trench to the bottom. As used herein, “top”, “above”, and “top” will be used to describe portions/directions that are vertically away from the substrate plane and vertically away from the major plane of the substrate. "Vertical" will be used to describe items that are aligned in an "up" direction towards "top". Other similar terms may now be used whose meanings will be clarified.

Exemplary low vapor pressure precursors include precursors that can be used to form self-assembled monolayers (SAMs). Although the techniques described herein may be used for many more than those presented below, illustrative examples may aid in understanding the embodiments disclosed herein. The precursors used to deposit the self-assembled monolayers have tail moieties chemically distinct from the head moieties (HM), which have been found to aid in the formation of self-assembled monolayers. moieties)(TM). The precursors may be phosphonic acids comprising HM having the formula PO(OH) ₂ . According to embodiments, the low vapor pressure agglomeration material precursors are octylphosphonic acid (CH ₃ (CH ₂ ) ₆ CH ₂ -P(O)(OH) ₂ ), perfluorooctylphosphonic acid (CF ₃ (CF 3 ) ₂ ) ₅ CH ₂ -CH ₂ -P(O)(OH) ₂ ), octadecylphosphonic acid (CH ₃ (CH ₂ ) ₁₆ CH ₂ -P(O)(OH) ₂ ), decylphosphonic acid, one or more of mesityl phosphonic acid, cyclohexyl phosphonic acid, hexyl phosphonic acid, or butyl phosphonic acid.

[0046] The tail moiety (TM) may prevent or interfere with film formation on the patterned layer during subsequent exposure to the second deposition precursor. According to embodiments, the tail moiety of the phosphonic acid precursor is a perfluorine having more than 5 carbon atoms, more than 6 carbon atoms, or more than 7 carbon atoms covalently bonded to each other in a chain. may contain an alkyl group. The presence of larger fluorine atoms replacing the much smaller hydrogen atoms appears to prevent nucleation of the patterned layer for smaller carbon chains. In embodiments, the tail moiety of the phosphonic acid precursor may comprise an alkyl group having more than 12 carbon atoms, more than 14 carbon atoms, or more than 16 carbon atoms, covalently linked in a chain. can According to embodiments, the TM may include linear or aromatic hydrocarbons such as —CH ₂ , C ₆ H ₅ , C ₆ H ₄ , C ₂ H ₅ , or —CH ₂ CH ₂ CH ₃ .

[0047] The precursors used to deposit a self-assembled monolayer (SAM) can provide a head moiety that covalently bonds with the substrate, and a tail moiety that extends from the covalent bond away from the substrate. The tail moiety comprises a relatively long covalently-linked sequence referred to as a chain. In embodiments, the SAM may be stable (decomposition resistance) up to substrate temperatures of 300 °C or 350 °C. The HM of the chemical precursor molecule may contain sulfur-containing groups such as thiol groups. According to embodiments, the precursor is methanethiol (CH ₃ SH), ethanethiol (C ₂ H ₅ SH), or butanethiol (C ₄ H ₉ SH), N-alkanethiols {CH ₃ (CH ₂ ) _n-1 SH, wherein n can be one or more of 8, 12, 16, 18, 20, 22, or 29}. In embodiments, the precursor comprises CF ₃ and CF ₂ terminated thiols, such as CF ₃ (CF ₂ ) _n (CH ₂ ) ₁₁ )SH and CF ₃ (CF ₂ ) ₉ (CH ₂ ) _n SH (here where n can be one or more of 2, 11, or 17), and (CF ₃ (CH ₂ ) _n SH), wherein n is 9 to 15). According to embodiments, the head group may contain a nitrogen containing group. In embodiments, the precursor is 3-aminopropyltriethoxysilane (APTES), (3-aminopropyl)trimethoxysilane (APTMS), 1,3 diamino propane, ethylenediamine, ethylenediaminetetraacetic acid, di one or more of ethylamine, and methylamine.

[0048] The deposition rate of the film onto the patterned layer over the SAM can be much less than the deposition rate of the film over portions not covered by the self-assembled monolayer. The deposition rate of the film over the SAM can be reduced by the presence of the SAM, and the deposition rate can be much lower than if the SAM was not present. In embodiments, the deposition rate over the SAM-free portions may be greater than one hundred times, greater than one hundred fifty times, or greater than two hundred times the growth rate on the SAM portions. The presence or absence of the SAM layer can be determined by the difference in the affinity of the low vapor pressure precursor for the different exposed portions on the patterned substrate. For example, the deposition rate of the SAM may readily proceed over exposed metal portions, but not over exposed dielectric portions of the patterned substrate. The metal portion may be electrically conductive and may comprise or consist of elements that form a conductive material in a state of agglomerated matter in the absence of other elements. In embodiments, the deposition rate of the SAM layer on the exposed metal portion may exceed the deposition rate on the exposed dielectric portion by a factor of 10, 15, 20, or 25.

In embodiments, the precursors may be deposited on both or more chemically distinct portions of the patterned layer, but may form covalent bonds on only one of the two portions. On the other part, the precursors can be bound by physisorption, meaning that no covalent bonds are formed between the precursors and the second exposed surface part. In this scenario, the physisorbed precursors can be easily removed while allowing the chemisorbed (covalently bonded) precursors to stay. This is an alternative method for creating a selectively-deposited SAM layer.

[0050] A self-assembled monolayer (SAM) as grown herein may be selectively deposited on some portions of the patterned substrate without being deposited on other portions of the patterned substrate. After that, subsequent deposition can proceed only on areas without the SAM coating. The methods described herein can provide cost savings and increased overlay accuracy as compared to conventional methods involving lithographic patterning. After SAM selective deposition, subsequent deposition may also be referred to as selective deposition, but is an inverted image of the selectively deposited SAM layer. Subsequent deposited films may have greater utility (compared to SAM) in the function of a finished integrated circuit or in further processing. 3A, 3B, and 3C are side views of the patterned substrate at points during and after the selective deposition of the self-assembled monolayer 310 and selectively deposited dielectric 315-1. In FIG. 3A , a self-assembled monolayer 310 is deposited on the exposed copper 305 in the gap in the patterned substrate 301 , but not on the other exposed portions. The exposed copper 305 may be bare, ie, may have no liner layer or barrier layer between the self-assembled monolayer 310 and the top of the copper 305 .

3B shows a selectively deposited dielectric 315-1 formed at locations that do not have a self-assembled monolayer, ie, locations that are not copper in this example. As shown in FIG. 3C , self-assembled monolayer 310 is selectively deposited dielectric 315 - 1 everywhere except inlaid copper 305 in the gaps of patterned substrate 301 . ) can be removed to leave 3D is a side view of a patterned substrate after selective deposition of a self-assembled monolayer, not using embodiments disclosed herein. Prior art methods of forming self-assembled monolayers were tested using the process flow of FIGS. 3A-3C , covering portions of inlaid copper 305 , and increasing resistivity in finished devices or completed. It tends to create a selectively deposited dielectric 315-2 that causes failure of old devices.

[0052] FIG. 4 shows a chart of contact angle for materials without and with an adsorbed self-assembled monolayer, according to embodiments. The contact angle was measured for each surface by wetting the surface with deionized water and observing the angle formed by the deionized water for various materials. Silicon oxide, low-k dielectric, copper, and titanium nitride were defined to measure the contact angle, and four materials are shown from left to right. Each dashed rectangle in Figure 4 represents one of four materials and contains two measurements: one measurement from the bare surface and one measurement denoted as octadecylphosphonic acid (ODPA). ) after exposure to Only copper exhibits a statistically-significant difference between the bare surface and the surface exposed to octadecylphosphonic acid. The absence of differences between the exposed and bare surfaces is the basis for the absence of chemisorption of octadecylphosphonic acid onto silicon oxide, low-k dielectric, and titanium nitride, respectively. In embodiments, the self-assembling monolayer may be formed on some portions of the patterned substrate (eg, copper) without forming on other portions of the patterned substrate. According to embodiments, thereafter, subsequent deposition may proceed only on areas that do not have a SAM coating.

[0053] According to embodiments, exemplary solvents that may be used to dissolve the low vapor pressure agglomeration material precursor are isopropyl alcohol (IPA), 1-butanol, toluene, xylene, benzene, hexane, cyclohexane, tetrahydro one or more of furan, dimethyl sulfoxide, dimethylformamide, acetonitrile, dichloromethane, ethyl acetate, and chloroform. In embodiments, the solvent may include an aromatic hydrocarbon, may include carbon and hydrogen, or may consist of carbon and hydrogen, or may include carbon, hydrogen and oxygen, or may include carbon, hydrogen and oxygen can be composed of

5A shows a schematic cross-sectional view of a substrate processing chamber according to embodiments, which may be used to perform previously described methods. The substrate temperature may be raised above room temperature during deposition, depending on the type of film being grown. The dry processes introduced herein allow processes to be performed at higher temperatures than prior art liquid processes. Small aerosol droplets may exit the holes of the quartz baffle 1012 , after which the substrate is maintained at a temperature of 100 °C to 800 °C, 200 °C to 700 °C, 300 °C to 600 °C, or 400 °C to 500 °C In the meantime, the substrate 1013 can be accessed and contacted with the substrate 1013 . These substrate temperatures apply for all deposition operations described herein. The chamber body 1006 and/or the top lid 1005 provides vacuum integrity between the substrate processing region inside the quartz baffle 1012/quartz housing 1016 and the atmosphere outside the chamber body 1006 and the top lid 1005 . may be stainless steel (eg SST 304 or preferably SST 316) capable of withstanding relatively high temperatures (possibly up to 400° C.) while maintaining The chamber body 1006 , the top lid 1005 , and any other components have O-rings compatible with the particular process environment to ensure gas isolation between the substrate processing region and the atmosphere outside the substrate processing chamber 1001 . can be sealed with

The chamber body 1006 and/or the top lid 1005 may be cooled, for example, by flowing coolant through coolant channels formed or machined through stainless steel. Coolant channels may be provided near the O-ring connections to protect the O-rings from exposure to high temperatures. The temperatures of the chamber body 1006 and/or the top lid 1006 are adjusted to reduce or stabilize the base pressure in the quartz housing 1016 and the quartz baffle 1012 (substrate processing region) for film formation. It can be kept below 70 °C during the period. The presence of the quartz baffle 1012 and quartz housing 1016 may further facilitate a reduction in the operating temperature of the chamber body 1006 and/or top cover 1005 . The quartz baffle 1012 (eg, a quartz portion having openings), the top electrode 1009 , and/or the bottom electrode 1010 may be kept below 100° C. during film formation. The substrate pedestal 1014 may be heated to desired temperatures of the previously provided substrate 1013 and may maintain the temperature of the substrate 1013 at a level that assists the process. The substrate pedestal 1014 may be vertically adjustable to provide flexibility in positioning the substrate 1013 relative to the bottom of the quartz baffle 1012 . Thermocouples may be attached to or within the chamber body 1006 and/or top lid 1005 to provide feedback control of coolant flow rate and/or temperature. can be embedded. Thermocouples may also be used to shut down the precursor flow rate and also shut down heat to the substrate pedestal 1014 when the upper safe temperature set point is exceeded.

In embodiments, the pressure in the substrate processing region during the deposition processes described herein may be between 10 Torr and 750 Torr, between 20 Torr and 700 Torr, or between 100 Torr and 600 Torr. According to embodiments, the reactions may proceed thermally by being excited only by the temperature of the substrate itself. In embodiments that rely on the temperature of the substrate to generate the deposition reaction, the term “plasma-free” is used herein to refer to applications that do not use, or essentially do not use, plasma power. can be used to describe a region of substrate processing during The absence of plasma in the substrate processing region will be quantified in several complementary ways that may be used individually or in combination. Plasma power may also be maintained below small threshold amounts to allow proper reactions to proceed. In embodiments, the plasma power applied to the substrate processing region may be less than 100 watts, less than 50 watts, less than 30 watts, less than 10 watts, and may be 0 watts.

The absence of any localized plasma (or reduction in size) preferably makes the deposition processes more conformal and less likely to deform features. The term “plasma-free” will be used herein to describe a substrate processing region during which no plasma power is applied or essentially no plasma power is applied to the substrate processing region. Stated another way, according to embodiments, the electron temperature in the substrate processing region may be less than 0.5 eV, less than 0.45 eV, less than 0.4 eV, or less than 0.35 eV. In embodiments, the low vapor pressure precursor is not excited by any remote plasma prior to entering the substrate processing region. For example, where a remote plasma region or a separate chamber region exists and is used to conduct aerosol droplets towards a substrate processing region, any remote region(s), as defined herein, can be a plasma- can be free.

There is a gap (shown as electric field region 1011 in FIG. 5A ) between the top electrode 1009 and the bottom electrode 1010 . The gap forming the electric field region 1011 is measured between the bottom surface of the top electrode 1009 and the top surface of the bottom electrode 1010 . According to embodiments, the height of the electric field zone 1011 may be between 0.5 mm and 10 mm, or between 1 mm and 3 mm. In embodiments, the voltage applied between the top electrode 1009 and the bottom electrode 1010 to maintain or achieve small aerosol droplet sizes is a positive potential with respect to the bottom electrode 1010 to the top electrode 1009 . or a DC voltage that puts the bottom electrode 1010 at a positive potential with respect to the top electrode 1009 . According to embodiments, the magnitude of the DC voltage difference may be 100 volts to 2 kilovolts, 200 volts to 1,000 volts, or 500 volts to 800 volts. In embodiments, the DC electric field between the top electrode 1009 and the bottom electrode 1010 is 500 V/cm to 20,000 V/cm, 1,000 V/cm to 10,000 V/cm, or 2,000 V/cm to 7,000 V It can have a size of /cm. According to embodiments, it has been found that small diameter droplets are reduced or their size maintained by application of a DC electric field, even in cases where the aerosol droplets are uncharged and non-polar.

Additional benefits of the processes and hardware described herein may now be described. Prior art aerosol droplets have had diameters of about 0.5 μm to several μm. Several problems arise from having large diameter droplets that deliver precursors to the substrate. According to embodiments, the aerosol droplets formed herein may have a diameter of 3 nm to 75 nm, 5 nm to 50 nm, or 10 nm to 25 nm. Small aerosol droplet dimensions facilitate penetration of precursor sources into smaller features on the patterned substrate. Smaller sizes may improve material gapfill and may result in fewer voids trapped within the gaps. Smaller sizes may also allow for more conformal deposition, as a result of the ability to penetrate narrow gaps. Aerosol droplets with smaller sizes also increase the surface to volume ratio, which allows for faster release of elements present in the low vapor pressure precursor (and solvent, if used). Some elements are undesirable in the deposited film. The smaller droplet sizes described herein allow undesirable elements (eg, carbon or hydrogen) to form volatile species that readily leave the surface during the deposition reaction. Additional benefits include reduction in the size and number of grain boundaries, as well as reduction in surface roughness, by using the techniques described herein.

Small aerosol droplets may be initiated using ultrasonic agitation in aerosol generators 1003 . As discussed, the size of the aerosol droplets may be reduced (or growth of the aerosol droplets may be inhibited) by applying a DC electric field to the electric field region 1011 before the aerosol droplets pass into the substrate processing region. Aerosol generators 1003 to further reduce the sizes of aerosol droplets that the particle filter 1019 is allowed to pass through the precursor conduits 1015 , through the electric field region 1011 , and into the substrate processing region. It can be installed downstream from According to embodiments, the particle filter 1019 is capable of allowing aerosol droplets having a diameter of less than 0.3 μm, less than 0.25 μm, or less than 0.2 μm to pass through, while droplets having diameters greater than those size thresholds. may inhibit or inhibit their flow. The filter may be disposed anywhere along the precursor conduits 1015 , including directly above the top electrode 1009 . In embodiments, the filter may be located at the top electrode 1009 , at the electric field region 1011 , at the bottom electrode 1010 , or even downstream of the bottom electrode 1010 . The sizes of aerosol droplets can be measured using in-situ particle size analyzers (eg, an aggregated particle counter or detector).

The substrate processing region within the substrate processing chamber 1001 may be evacuated using a vacuum pump 1017 prior to introducing aerosol droplets into the substrate processing region during all deposition operations described herein. Some chemicals, after passing through the vacuum pump 1017 , may require additional processing before being released to the atmosphere. A scrubber 1018 may be disposed downstream from the vacuum pump 1017 to modify or remove chemical components of the process effluents prior to discharging them. A closed-loop exhaust feedback system may be used to maintain the desired pressure within the substrate processing region. When the pressure within the substrate processing region is measured to exceed the set point pressure (an overpressure situation), an automatic valve (not shown) opens the substrate processing region to the vacuum pump 1017 and scrubber 1018 to , to release the pressure inside the substrate processing chamber 1001 .

[0062] The equipment and techniques described herein may be useful for etching or forming various layers including metals, semiconductors, and insulators. According to embodiments, the layers may be conformal, self-assembled monolayers (SAM) formed from organic or inorganic molecules, or may be atomic layer deposition (ALD). As purely illustrative examples, films that may be etched or deposited using these techniques include indium gallium arsenide, indium gallium phosphide, gallium arsenide, and titanium oxide. In embodiments, the films may be metal oxides, III-V semiconductors, or II-VI semiconductors.

5A shows two aerosol generators 1003-1 and 1003-2 for delivering low vapor pressure precursors into a substrate processing region. There may be more than two aerosol generators, which may be powered by non-aerosol generating sources not shown in the figure simply to increase readability. Alternatively, transducers in one or more of the aerosol generators may be excluded to provide a non-aerosol generating source for the hardware shown. During film growth, one or more of the aerosol generating sources may be used to deliver dopant(s) to the film, as may be useful when growing a semiconductor doped with an electron acceptor or donor. In this manner, an n-type or p-type semiconductor (eg, silicon) may be formed using the techniques and hardware described herein.

FIG. 5B shows a schematic cross-sectional view of another substrate processing chamber 1101 , according to embodiments, that may also be used to perform previously described methods. Features and elements of each embodiment may be added to some or all features and elements of another embodiment to arrive at further embodiments. A substrate 1113 is disposed within a substrate processing region of the substrate processing chamber 1101 for deposition. The substrate 1113 is supported on the bottom electrode 1114 . A carrier gas flows from the carrier gas supply 1102 through the carrier gas supply valve 1104 and into the aerosol generator 1110 . The RF power supply 1106 is configured to supply an alternating electrical signal (eg, ultrasound) to a piezoelectric transducer 1108 disposed in physical contact with the aerosol generator 1110 . The piezoelectric transducer 1108 vaporizes a source of condensed material (eg, solid or liquid) of the precursor, and the carrier gas generated from the carrier gas supply 1102 flows through the aerosol generator 1110 and directs the vaporized precursor to the chamber inlet. transported through a valve 1111 into the substrate processing region of the substrate processing chamber 1101 . The carrier gas may be heated, as before, before passing through the carrier gas supply valve 1104 and entering the aerosol generator 1110 .

The bottom electrode 1114 is parallel to the top electrode 1112 , and vaporized precursor or aerosol droplets are delivered from between the electrodes into the substrate processing region. Figure 5a shows aerosol droplets delivered through one of the electrodes, and Figure 5b shows a configuration in which flow through the electrode is not required. A DC power supply (not shown at this time) applies a DC voltage between the top electrode 1112 and the bottom electrode 1114 to achieve or maintain a small droplet size in the vaporized precursor in the substrate processing region. is configured to The electric field is pointed from the top electrode 1112 towards the bottom electrode 1114 . To ensure independently controllable voltage levels, an electrical insulator is disposed between the top electrode 1112 and the bottom electrode 1114 . In embodiments, the DC voltage difference generated within the DC power supply is applied to the top electrode 1112 and the bottom electrode 1114 using vacuum feedthroughs, or directly to the electrodes without first passing through a vacuum. can be authorized In embodiments, the small size of the aerosol droplets is reduced or maintained through application of a DC electric field perpendicular to the substrate 1113 . In embodiments, the top electrode 1112 and the bottom electrode 1114 are parallel, each parallel to a major plane of the substrate 1113 . The substrate may be electrically biased during deposition. A film is deposited on the substrate 1113 from the aerosol droplets. Using a vacuum pump 1118, unreacted precursor or other process effluents may be pumped out, and a scrubber 1120 may be used to chemically modify the process effluents to increase environmental compatibility.

A heater coil 1116 may be disposed on the top electrode 1112 and/or the bottom electrode 1114 . Heating the top electrode 1112 and/or bottom electrode 1114 prevents agglomeration of the vaporized precursor and further reduces the droplet size. The substrate temperature may be raised above room temperature during deposition, depending on the type of film being grown. The dry processes introduced herein allow processes to be performed at higher temperatures than prior art liquid processes. According to embodiments, the vaporized precursor is in contact with the substrate 1113 while the substrate is maintained at a temperature of 100 °C to 800 °C, 200 °C to 700 °C, 300 °C to 600 °C, or 400 °C to 500 °C. . Process pressures have also been provided previously and will not be repeated here for the sake of brevity. According to embodiments, the reactions may proceed thermally by being excited only by the temperature of the substrate itself. The substrate processing region may be described as plasma-free, which has been previously defined. According to embodiments, a gap between the top electrode 1112 and the bottom electrode 1114 may be between 1.0 mm and 10 mm, or between 1.5 mm and 3 mm. Voltages, electric field strengths, droplet sizes, and process benefits have been presented previously.

FIG. 5C shows a schematic cross-sectional view of another substrate processing chamber 1201 , according to embodiments, which may also be used to perform previously described methods. Features and elements of each embodiment may be added to some or all features and elements of another embodiment to arrive at further embodiments. A substrate 1215 is placed in a substrate processing region of the substrate processing chamber 1201 prior to deposition. A substrate 1215 is supported on a substrate pedestal 1216 . In embodiments, substrate pedestal 1216 may be a vacuum compatible material that is an electrical insulator. The substrate pedestal 1216 may further be configured to be vacuum compatible at the substrate temperatures described herein. In embodiments, substrate pedestal 1216 may be a block of carbon and may include or consist of carbon. A carrier gas flows from the carrier gas supply 1202 into the aerosol generator 1210 and is bubbled through the liquid precursor 1206 . An RF power supply (not shown) is configured to supply an alternating electrical signal (eg, ultrasound) to a piezoelectric transducer 1204 disposed inside the aerosol generator 1210 . The piezoelectric transducer 1204 may be vibrated to beneficially facilitate delivery of aerosol droplets of liquid precursor 1206 material towards a substrate processing region of the substrate processing chamber 1201 .

[0068] In certain such embodiments, the electrodes are vertically aligned. The first electrode 1214 is again parallel to the second electrode 1218 , and vaporized precursor or aerosol droplets are delivered through the first electrode 1214 into the substrate processing region between the electrodes. FIG. 5a shows aerosol droplets delivered through one of the electrodes, and FIG. 5c likewise shows a configuration having such a property. A DC power supply (not shown) is configured to apply a DC voltage between the first electrode 1214 and the second electrode 1218 to achieve or maintain a small droplet size in the vaporized precursor in the substrate processing region. is composed The electric field is pointed from the first electrode 1214 towards the second electrode 1218 . All direct connections between the first electrode 1214 and the second electrode 1218 are electrically insulated. In embodiments, the inlet plate 1212 may also be electrically isolated from the first electrode 1214 by inserting an inlet insulator 1213 between the first electrode 1214 and the inlet plate 1212 . Similarly, outlet plate 1220 can be electrically isolated from second electrode 1218 by inserting outlet insulator 1219 between first electrode 1218 and outlet plate 1220 . In embodiments, the DC voltage difference created within the DC power supply is applied directly to the electrodes using vacuum feedthroughs, or without first passing through a vacuum, first 1214 and second 1218 electrodes. ) can be approved. In embodiments, the small size of the aerosol droplets is reduced or maintained through application of a DC electric field parallel to the substrate 1215 , in contrast to each of the embodiments shown in FIGS. 5A and 5B . In embodiments, first electrode 1214 and second electrode 1218 are planar, each perpendicular to a major plane of substrate 1215 . A film is deposited on the substrate 1215 from the aerosol droplets. According to embodiments, unreacted precursor or other process effluents may be pumped out through second electrode 1218 , outlet insulator 1219 , and outlet plate 1220 . Process effluents may be pumped out via vacuum pump 1222 . Substrate temperatures, process pressures, electric field strengths, droplet sizes, and process benefits have been presented previously.

6 shows a schematic contrast of deposition techniques including methods according to embodiments. Wet spray pyrolysis, dry spray pyrolysis, aerosol-assisted CVD (methods herein), and powder spray pyrolysis are each represented and compared in FIG. 6 . Wet and dry spray pyrolysis, aerosol-assisted CVD (AACVD), and powder spray pyrolysis each can have the ability to form large droplets 1511 . Large droplets 1511 may separate from carrier fluid 1512 in cases of dry spray pyrolysis, AACVD, and powder spray pyrolysis. The droplets are further reduced in size and remain small in size using aspects of the methods and instrumentation described herein for vaporizing precursors 1531 . Desirable uniformity of thin film 1541 is achieved by reducing the sizes of precursor amalgamations down to and including individual molecular components. A uniform thin film 1541 is formed on the substrate 1551 , but clumping is still observed in wet spray pyrolysis, dry spray pyrolysis, and powder spray pyrolysis, respectively.

[0070] Examples discussed so far use low vapor pressure precursors to deposit films on a substrate via alternating exposure or successive exposure. The techniques described herein may also be used to perform etching by alternating or successive exposure through exposure to an etching precursor (etchant) having a low vapor pressure. In embodiments, the low vapor pressure etchant may be a halogen-containing precursor, a fluorine-containing precursor, a chlorine-containing precursor, or a bromine-containing precursor. According to embodiments, the low vapor pressure etchant may be a metal-and-halogen-containing precursor, wherein the halogen may be fluorine, chlorine, or bromine. Similarly, in embodiments, the low vapor pressure etchant may be a halon (eg, a haloalkane). A low vapor pressure etchant may possess a long alkyl chain, as described elsewhere herein, which is associated with lower vapor pressures improved by the techniques presented herein.

[0071] In embodiments, the processes described herein may involve removal of a monolayer during each alternating exposure to a first precursor and a second precursor. According to embodiments, the processes described herein may involve deposition of a monolayer of material during each alternating exposure to a first precursor and a second precursor. Both the first precursor and the second precursor may be low vapor pressure precursors prepared with aerosol generating techniques. Alternatively, one of the precursors may be low vapor pressure precursors that may be prepared using aerosol generating techniques and the other may have a relatively high vapor pressure and delivered to the substrate processing region by simpler conventional means. can be

[0072] In all embodiments described herein, the low vapor pressure agglomerated material precursor (eg, solid precursor or liquid precursor) is 5 mgm (milligrams per minute) to 500 mgm, 10 mgm to 300 mgm, or 25 mgm to 200 mgm It can be supplied at a flow rate of Two or more low vapor pressure agglomerate precursors may be used, in which case each low vapor pressure aggregated material precursor may have a flow rate between the ranges given above. Other types of precursors may also be used, as may be the case for atomic layer deposition. In any of the embodiments described herein, the other precursor may be supplied at a flow rate of 5 sccm to 2,000 sccm, 10 sccm to 1,000 sccm, or 25 sccm to 700 sccm. Film formation rates using the aerosol droplet generation methods and hardware described herein, in contrast to the slow deposition rates of prior art aerosol-assisted chemical vapor deposition, may in embodiments exceed 300 Å/min, or may exceed 500 Å/min, or may exceed 1,000 Å/min.

Each of the described embodiments can retain evacuation operations between sequentially alternating exposures during atomic layer deposition processes. Generally speaking, the deposition and etching operations of all processes described herein may instead simply have an interruption in the flow of precursors into the substrate processing region during alternating exposure deposition sequences. Alternatively, the substrate processing region may be actively purged using a gas that is not inherently chemically reactive to exposed materials on the patterned substrate. After precursor cessation or active purging, the next precursor may be flowed into the substrate processing region to continue etching/deposition of/on the patterned substrate.

[0074] A metal may include or be composed of a “metal element” that forms a conductive material as a solid composed solely of a metal element. In embodiments, a conductive material composed of only one metallic element (or a metal in a relatively pure form) may have a conductivity of less than 10-5 Ω-m at 20°C. According to embodiments, a conductive material may form ohmic contacts when bonded with another conductive material. A metal region as described herein may be composed of a metal element(s), or may also be a metal nitride, which causes nitrogen, typically a low electronegativity, to allow the metal nitride to maintain electrical conductivity. because it has In embodiments, the metal nitride may include elemental metal and nitrogen, and may consist of elemental metal and nitrogen. In the exemplary case of tungsten and tungsten nitride, the metal may include or consist of tungsten, and the metal nitride may include tungsten and nitrogen, or may consist of tungsten and nitrogen.

[0075] An advantage and benefit of the processes described herein lies in a conformal rate of etching or deposition of materials on a substrate. As used herein, terms such as conformal etch, conformal deposition, and conformal film refer to films or removal rates that conform to the contours of a patterned surface, regardless of the shape of the surface. The removal rate or top and bottom surfaces of the deposited layer may be generally parallel. One of ordinary skill in the art will recognize that the deposition process may not be 100% conformal, and thus, the term “usually” allows for acceptable tolerances. Similarly, a conformal layer refers to a layer having a generally uniform thickness. The conformal layer may have an outer surface of the same shape as the inner surface.

Embodiments of substrate processing chambers may be incorporated into larger fabrication systems for producing integrated circuit chips. 7 shows one such substrate processing system (mainframe) 2101 of deposition, etch, bake, and cure chambers in embodiments. In the figure, a pair of front opening unified pods (load lock chambers 2102) are received by robotic arms 2104 and placed into one of substrate processing chambers 2108a - 2108f. Substrates of various sizes are supplied to be placed in the low pressure holding area 2106 before being used. The second robotic arm 2110 may be used to transport substrate wafers from the holding area 2106 to the substrate processing chambers 2108a - 2108f and back. Each of the substrate processing chambers 2108a - f is a cyclic layer deposition (CLD), atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), etching, atomic layer etching, pre-clean, In addition to degassing, orientation, and other substrate processes, it may be equipped to perform a number of substrate processing operations, including the dry etching processes described herein.

[0077] As used herein, a “patterned substrate” may be a support substrate with or without layers formed thereon. The patterned substrate may be a semiconductor or insulator of various doping concentrations and profiles, for example a semiconductor substrate of the type used in the manufacture of integrated circuits. The exposed “metal” of the patterned substrate is primarily a metallic element, but may include minor concentrations of other elemental constituents such as nitrogen, oxygen, hydrogen, silicon, and carbon. The exposed “metal” may consist of, or consist essentially of, a metallic element. The exposed “metal nitride” of the patterned substrate is primarily nitrogen and metallic elements, but may contain minor concentrations of other elemental constituents such as oxygen, hydrogen, silicon, and carbon. The exposed "metal nitride" may consist of nitrogen and metal elements, or may consist essentially of nitrogen and metal elements. Other examples of layers that may be processed according to the methods described herein include titanium oxide, aluminum oxide, zirconium oxide, titanium-doped silicon oxide, and hafnium oxide.

The exposed “silicon” or “polysilicon” of the patterned substrate is primarily Si, but may contain minor concentrations of other elemental components such as nitrogen, oxygen, hydrogen, and carbon. Exposed “silicon” or “polysilicon” may consist of, or consist essentially of, silicon. The exposed “silicon nitride” of the patterned substrate is primarily silicon and nitrogen, but may contain minor concentrations of other elemental constituents such as oxygen, hydrogen, and carbon. "Exposed silicon nitride" may consist of silicon and nitrogen, or may consist essentially of silicon and nitrogen. The exposed “silicon oxide” of the patterned substrate is predominantly SiO2, but may contain minor concentrations of other elemental components (eg, nitrogen, hydrogen, carbon). In some embodiments, silicon oxide regions etched using the methods disclosed herein consist essentially of silicon and oxygen.

[0079] The carrier gases described herein may be inert gases. The phrase “inert gas” refers to any gas that does not form chemical bonds when incorporated into or etching into a layer. Exemplary inert gases include noble gases, but may include other gases as long as no chemical bonds are formed when (typically) trace amounts are trapped in the layer.

[0080] A gap is an etched geometry having any horizontal aspect ratio. Viewed from above the surface, the gaps may appear as circular, oval, polygonal, rectangular, or various other shapes. A "trench" is a long gap. The trench may be in the shape of a moat around an island of material, wherein the aspect ratio is the length or perimeter of the moat divided by the width of the moat. A “via” is a short gap with a horizontal aspect ratio when viewed from above that is almost unity. Vias may appear as round, slightly oval, polygonal, or slightly rectangular. Vias may or may not be filled with metal to form vertical electrical connections.

While several embodiments have been disclosed, it will be appreciated by those skilled in the art that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the disclosed embodiments. Additionally, many well-known processes and elements have not been described in order to avoid unnecessarily obscuring the disclosed embodiments. Accordingly, the above description should not be taken as limiting the scope of the claims.

[0082] Where a numerical range is given, each value present between the upper and lower limits of that numerical range is also specifically recited to one additional decimal place of the unit of the lower limit, unless the context clearly dictates otherwise. is interpreted as Each subrange between any specified value within a specified range or a value within that range and any other specified value within that specified range or other value within that specified range is included. The upper and lower limits of such subranges can independently be included in or excluded from such a range, and each range depends on whether one or both of the upper and lower limits are included in or excluded from such subrange. However, unless any limit is specifically excluded from the stated range, it is also encompassed by the disclosed embodiments. Where the stated range includes one or both of the limits, ranges excluding either or both of the limits so included are also included.

[0083] As used herein and in the appended claims, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a process” includes a plurality of such processes, and reference to “the dielectric material” includes reference to one or more dielectric materials and equivalents thereof known to those skilled in the art. Including a reference to , the other cases are similar.

[0084] Also, when used in this specification and the claims that follow, the words "comprise," "comprising," "include," "including," and "includes" refer to the mentioned features; Although intended to specify the presence of integers, components, or steps, they do not preclude the presence or addition of one or more other features, integers, components, steps, acts, or groups.

Claims (17)

A method for forming a layer on a substrate, comprising:
placing the substrate within a substrate processing region of a substrate processing chamber;
placing the liquid precursor into the aerosol generator;
flowing a carrier gas into the aerosol generator to generate aerosol droplets;
passing the aerosol droplets down through the holes in the top electrode, through the electric field under the top electrode, and then down through the holes in the bottom electrode, wherein the aerosol droplets are uncharged;
applying the electric field to the aerosol droplets by applying a voltage between the top electrode and the bottom electrode;
flowing the aerosol droplets through holes in the bottom electrode into the substrate processing region; and
forming a layer on the substrate from the aerosol droplets
A method for forming a layer on a substrate comprising: The method of claim 1,
wherein the layer is self-assembled monolayers (SAM). 3. The method of claim 2,
The self-assembled monolayer is selectively formed on exposed copper portions of the substrate that are not exposed dielectric portions of the substrate, the method comprising exposed copper portions that are not shielded by the self-assembling monolayer. A method for forming a layer on a substrate, further comprising forming a selectively deposited dielectric over the dielectric portions. 4. The method of claim 3,
wherein the selectively deposited dielectric is one of silicon oxide, hafnium oxide, zirconium oxide, titanium oxide, or titanium-doped silicon oxide. The method of claim 1,
The liquid precursor is octylphosphonic acid (CH ₃ (CH ₂ ) ₆ CH ₂ -P(O)(OH) ₂ ), perfluorooctylphosphonic acid (CF ₃ (CF ₂ ) ₅ CH ₂ -CH ₂ - P(O)(OH) ₂ ), octadecylphosphonic acid (CH ₃ (CH ₂ ) ₁₆ CH ₂ -P(O)(OH) ₂ ), decyl phosphonic acid, mesityl phosphonic acid, cyclohexyl phosphonic acid A method for forming a layer on a substrate comprising one or more of phonic acid, hexyl phosphonic acid, or butyl phosphonic acid. The method of claim 1,
wherein the layer is one of a II-VI semiconductor or a III-V semiconductor. The method of claim 1,
wherein the layer is one of boron nitride, aluminum nitride, gallium arsenide, gallium phosphorus, indium arsenide, or indium antimonide. The method of claim 1,
wherein the layer is a metal-oxide. The method of claim 1,
the layer is composed of oxygen and metal elements,
A method for forming a layer on a substrate. The method of claim 1,
wherein the electric field is a DC electric field with an electric field pointed towards the substrate;
A method for forming a layer on a substrate. The method of claim 1,
and flowing a second precursor into the substrate processing region to form a monolayer on the layer. A method for processing a layer on a substrate, comprising:
placing the substrate within a substrate processing region of a substrate processing chamber;
dissolving the solid precursor in a solvent to form a precursor solution in the aerosol generator;
flowing a carrier gas into the aerosol generator to generate aerosol droplets;
passing the aerosol droplets down through the holes in the top electrode, through the electric field under the top electrode, and then down through the holes in the bottom electrode, wherein the aerosol droplets are uncharged;
applying the electric field to the aerosol droplets by applying a voltage between the top electrode and the bottom electrode;
flowing the aerosol droplets through holes in the bottom electrode into the substrate processing region; and
etching the layer on the substrate by chemical reaction with the aerosol droplets;
A method for processing a layer on a substrate comprising: 13. The method of claim 12,
wherein the layer consists of two elements. 13. The method of claim 12,
flowing a second precursor into the substrate processing region to remove one monolayer from the layer. 13. The method of claim 12,
wherein the electric field is a DC electric field with an electric field pointed towards the substrate. 13. The method of claim 12,
wherein the electric field has a magnitude of 500 V/cm to 20,000 V/cm. 13. The method of claim 12,
wherein the aerosol droplets have a diameter between 3 nm and 75 nm.

Images