US 7595088 B2
A method of depositing a silicon oxide layer over a substrate having a trench formed between adjacent raised surfaces. In one embodiment the silicon oxide layer is formed in a multistep process that includes depositing a first portion of layer over the substrate and within the trench by forming a high density plasma process that has simultaneous deposition and sputtering components from a first process gas comprising a silicon source, an oxygen source and helium and/or molecular hydrogen with highD/S ratio, for example, 10-20 and, thereafter, depositing a second portion of the silicon oxide layer over the substrate and within the trench by forming a high density plasma process that has simultaneous deposition and sputtering components from a second process gas comprising a silicon source, an oxygen source and molecular hydrogen with a lowerD/S ratio of, for example, 3-10.
1. A method of depositing a silica glass film on a substrate disposed in a substrate processing chamber, the substrate having a trench formed between adjacent raised surfaces, the method comprising:
flowing a process gas comprising a silicon source, an oxygen source, and molecular hydrogen into the substrate processing chamber;
forming a plasma having an ion density of at least 1011 ions/cm3 from the process gas to deposit the silicon oxide film over the substrate and in the trench in a process that has simultaneous deposition and sputtering components; and
increasing a flow rate of the molecular hydrogen during deposition of the silicon oxide film.
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9. A method of depositing a silica glass film on a substrate disposed in a substrate processing chamber, the substrate having a trench formed between adjacent raised surfaces, the method comprising:
flowing a process gas comprising a silicon source, an oxygen source, and a fluent gas, the fluent gas comprising at least two chemically distinct component gases;
forming a plasma having an ion density of at least 1011 ions/cm3 from the process gas to deposit the silicon oxide film over the substrate and in the trench in a process that has simultaneous deposition and sputtering components; and
varying relative flow rates of the component gases to decrease an average molecular weight of the fluent gas flowed to the substrate processing chamber during deposition of the silicon oxide film.
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one of the component gases has a lower molecular mass than all of the other component gases; and
varying relative flow rates of the component gases during deposition of the silicon oxide film comprises increasing a flow rate of the one of the component gases.
15. The method recited in
one of the component gases has a higher molecular mass than any of the other component gases; and
varying relative flow rates of the component gases during deposition of the silicon oxide film comprises decreasing a flow rate of the one of the component gases.
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18. A method of depositing a silica glass film on a substrate disposed in a substrate processing chamber, the substrate having a trench formed between adjacent raised surfaces, the method comprising:
depositing a first portion of the silica glass film over the substrate and within the trench by forming a high-density plasma to provide simultaneous deposition and sputtering from a first process gas comprising a silicon source, an oxygen source, and a first fluent gas that comprises helium He; and
thereafter depositing a second portion of the silica glass film over the substrate and within the trench by forming a high-density plasma to provide simultaneous deposition and sputtering from a second process gas comprising a silicon source, an oxygen source, and a second fluent gas that comprises molecular hydrogen H2,
wherein an average molecular mass of the second fluent gas is less than an average molecular mass of the first fluent gas.
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This application is a continuation of U.S. patent application Ser. No. 10/350,445, entitled “HYDROGEN ASSISTED HDP-CVD DEPOSITION PROCESS FOR AGGRESSIVE GAP-FILL TECHNOLOGY,” filed Jan. 23, 2003, the entire disclosure of which is incorporated herein by reference for all purposes.
The present invention relates to the manufacture of integrated circuits. More specifically, the invention relates to an improved method of depositing silicon oxide layers for use as a dielectric material in such integrated circuits.
One of the primary steps in the fabrication of modern semiconductor devices is the formation of a film, such as a silicon oxide, on a semiconductor substrate. Silicon oxide is widely used as an insulating layer in the manufacture of semiconductor devices. As is well known, a silicon oxide film can be deposited by thermal chemical vapor deposition (CVD) or a plasma-enhanced chemical vapor deposition (PECVD) processes. In a conventional thermal CVD process, reactive gases are supplied to the substrate surface where heat-induced chemical reactions (homogeneous or heterogeneous) take place to produce a desired film. In a conventional plasma process, a controlled plasma is formed to decompose and/or energize reactive species to produce the desired film.
Semiconductor device geometries have dramatically decreased in size since such devices were first introduced several decades ago. The dramatic reduction in device geometry has, in turn, dramatically increased the density of circuit elements and interconnections formed in integrated circuits fabricated on semiconductor substrates. One persistent challenge faced by semiconductor manufacturers in the design and fabrication of such densely packed integrated circuits is the desire to prevent spurious interactions between circuit elements.
Unwanted interactions are typically prevented by providing spaces (sometimes referred to herein as a “gap” or “trench”) between adjacent elements that are filled with an electrically insulative material to isolate the elements both physically and electrically. As circuit densities increase with smaller feature sizes, the widths of these spaces decrease, increasing their aspect ratio. The aspect ratio of a gap is defined by the ratio of the gap's height or depth to its width. High aspect ratio gaps are difficult to fill using conventional CVD methods. A film's ability to completely fill such gaps is referred to as the film's “gap-filling” ability. Silicon oxide based films (also referred to as “silica glass” based films) are one family of insulation films that is commonly used to fill the gaps in intermetal dielectric (IMD) applications, premetal dielectric (PMD) applications and shallow trench isolation (STI) applications among others. A silicon oxide film used in such an application is often referred to as a gap-fill film or a gap-fill layer.
Some integrated circuit manufacturers have turned to the use of high density plasma CVD (HDP-CVD) systems to deposit silicon oxide gap-fill layers. HDP-CVD systems form a plasma that is approximately two orders of magnitude or greater than the density of a standard, capacitively-coupled plasma CVD system. Examples of HDP-CVD systems include inductively-coupled plasma systems and electron cyclotron resonance (ECR) plasma systems among others. HDP-CVD systems generally operate at lower pressure ranges than low density plasma systems. The low chamber pressure employed in HDP-CVD systems provides active species having a long mean-free-path and reduced angular distribution. These factors, in combination with the plasma's density, contribute to a significant number of constituents from the plasma reaching even the deepest portions of closely spaced gaps, providing a film with improved gap-fill capabilities as compared to films deposited in a low density plasma CVD system.
Another factor that allows films deposited by HDP-CVD techniques to have improved gap-fill characteristics as compared to films deposited by other CVD techniques is the occurrence of sputtering, promoted by the plasma's high density, simultaneous with film deposition. The sputtering element of HDP deposition slows deposition on certain features, such as the corners of raised surfaces, thereby contributing to the increased gap-fill ability of HDP deposited films. Some HDP-CVD systems introduce argon or a similar heavy inert gas to further promote the sputtering effect. These HDP-CVD systems typically employ an electrode within the substrate support pedestal that enables the creation of an electric field to bias the plasma toward the substrate. The electric field can be applied throughout the HDP deposition process to further promote sputtering and provide better gap-fill characteristics for a given film.
It was initially thought that because of their simultaneous dep/etch nature, HDP-CVD processes could fill the gaps or trenches that were created in almost any application. Semiconductor manufacturers have found out, however, that there is a practical limit to the aspect ratio of gaps that HDP-CVD films are able to fill. For example, one HDP-CVD process commonly used to deposit a silicon oxide gap-fill film forms a plasma from a process gas that includes silane (SiH4), molecular oxygen (O2) and argon (Ar). It has been reported that when such a process is used to fill certain narrow-width, high aspect ratio gaps, the sputtering caused by argon in the process gas may hamper the gap-fill efforts. Specifically, it has been reported that material sputtered by argon in the process redeposits on the upper portions of the sidewalls of the gaps being filled at a rate faster than at the lower portions. This in turn, may result in the formation of a void in the gap if the upper areas of regrowth join before the gap is completely filled.
A variety of techniques have been developed to extend the gap-fill capabilities of silica glass HDP-CVD processes. Two specific examples include, U.S. Pat. Nos. 5,872,058 and 6,395,150, each of which is assigned to Novellus. The '058 patent discloses that the gap-fill capabilities of a silica glass film can be extended by reducing the amount of argon or other inert components in the HDP oxide process. Specifically, the '058 patent teaches that in order to fill higher aspect ratio gaps, it is important to limit the amount of inert components in the process gas to no more than 13 percent of the total gas mixture.
The '150 patent discloses that if argon, which is a diluent gas in addition to a sputtering agent, is eliminated from the process gas as suggested in the '058 patent, deposition rate uniformity may suffer. The '150 patent teaches this problem may be addressed by adding a flow of helium to the process gas. The '150 patent teaches that the amount of helium added should be between 15-90 percent of the total gas mixture and lists between 10-2000 sccm as an exemplary flow rate range. The '150 patent also lists hydrogen as an example of a diluent that can be used instead of helium. The '150 patent does not disclose specific details about what gaseous sources may be used to supply the hydrogen or how much hydrogen should be added.
Embodiments of the present invention pertain to methods of depositing silicon oxide films using HDP-CVD deposition techniques. These embodiments enable improved gap-fill capabilities as compared to some other known HDP-CVD silicon oxide deposition techniques and are particularly useful for the manufacture of integrated circuits having minimum feature sizes of 0.10 microns or less.
According to one embodiment of the invention, a silicon oxide layer is formed over a substrate having a trench formed between adjacent raised surfaces in a multi-step process that includes depositing a first portion of layer over the substrate and within the trench by forming a high density plasma process that has simultaneous deposition and sputtering components from a first process gas comprising a silicon source, an oxygen source and molecular hydrogen with higher D/S ratio of 10-20, and thereafter, depositing a second portion of the silicon oxide layer over the substrate and within the trench by forming a high density plasma process that has simultaneous deposition and sputtering components from a second process gas comprising a silicon source, an oxygen source and molecular hydrogen with lower D/S ratio of 3-10. In one specific embodiment, the first portion of the silicon oxide layer reduces the height of the trench by 30-65 percent and the second portion of the oxide layer completes the filling of the trench.
According to another embodiment of the invention, a silicon oxide layer is formed over a substrate having a trench formed between adjacent raised surfaces in a multi-step process that includes depositing a first portion of layer over the substrate and within the trench by forming a high density plasma process that has simultaneous deposition and sputtering components from a first process gas comprising a silicon source, an oxygen source and helium and, thereafter, depositing a second portion of the silicon oxide layer over the substrate and within the trench by forming a high density plasma process that has simultaneous deposition and sputtering components from a second process gas comprising a silicon source, an oxygen source and molecular hydrogen. In one specific embodiment, the first portion of the silicon oxide layer reduces the height of the trench by 10-50 percent and the second portion of the oxide layer completes the filling of the trench.
According to still another embodiment of the invention, a method of depositing a silicon oxide film on a substrate having a trench formed between adjacent raised surfaces includes flowing a process gas comprising a silicon source, an oxygen source, helium and molecular hydrogen into the chamber and decreasing over time a ratio of a flow rate of helium to molecular hydrogen. The method also includes forming a plasma having an ion density of at least 1×1011 ions/cm3 from the process gas to deposit the said silicon oxide layer over the substrate using a process that has simultaneous deposition and sputtering components. In one specific embodiment, the process gas includes only SiH4, O2 and helium during an initial stage of the deposition process; includes only SiH4, O2, helium and molecular hydrogen during a subsequent stage of deposition process; and includes only SiH4, O2 and molecular hydrogen during a final stage of the deposition process.
Embodiments of the invention can also be used in high density plasma deposition/etch/deposition (dep/etch/dep) silicon oxide gap-fill processes.
These and other embodiments of the present invention, as well as its advantages and features are described in more detail in conjunction with the text below and attached figures.
Embodiments of the invention are directed towards a method of depositing a silica glass layer to fill a gap in a surface of a substrate using a high density plasma CVD process. Silica glass films deposited according to the techniques of the invention have excellent gap-fill capabilities and are able to fill high aspect ratio gaps encountered in, for example, silicon trench isolation structures. Films deposited by the method of the invention are suitable for use in the fabrication of a variety of integrated circuits, and are particularly useful in the fabrication of integrated circuits having minimum feature sizes of 0.13 microns or less.
As used herein, a high density plasma process is a plasma CVD process that includes simultaneous deposition and sputtering components and that employs a plasma having an ion density on the order of 1×1011 ions/cm3 or greater. The relative levels of the combined deposition and sputtering characteristics of the high-density plasma may depend on factors such as the flow rates of various gases included in the gaseous mixture from which the plasma is formed as well as the source and bias power levels applied to maintain the plasma and bias the plasma towards the substrate, respectively. The combination of such factors may conveniently be quantified with a “deposition/sputter ratio,” sometimes denoted D/S to characterize the process:
As is known to those of skill in the art, other equivalent measures may be used to quantify the relative deposition and sputtering contributions of a HDP process. For example, a common alternative ratio is the “etching/deposition ratio,”
The desired D/S ratios for a given step in the HDP-CVD processes are generally achieved by including flows of one or more precursor gases and a fluent gas, which may also act as a sputtering agent. The elements comprised by the precursor gases react to form the film with the desired composition. For example, to deposit a silicon oxide film, the precursor gases may include a silicon-containing gas, such as monosilane SiH4, and an oxygen-containing gas, such as O2. Dopants may be added to the film by including a precursor gas with the desired dopant, such as by including a flow of SiF4 to fluorinate the film, including a flow of PH3 to phosphorate the film, including a flow of B2H6 to boronate the film, including a flow of N2 to nitrogenate the film, and the like. The fluent gas may be provided with a flow of H2 or with a flow of an inert gas, including a flow of He, a flow of Ne, a flow of Ar, a flow of Xe, a flow of Kr, or a flow of Rn. The level of sputtering provided by the different fluent gases is generally inversely related to their atomic mass (or molecular mass in the case of H2), with H2 producing even less sputtering than He.
In order to obtain optimal gap-fill characteristics in an HDP silicon oxide deposition process, the inventors have determined that the sputtering component of the process has to be decreased as compared to the sputtering component of many previously employed HDP oxide deposition processes. As stated previously, one known method of decreasing the sputtering component of an HDP oxide deposition process is by dramatically reducing (or eliminating) the flow of argon in the process. When argon is eliminated from the process gas, some previously developed processes added a flow of helium or hydrogen in order to compensate for a decrease in deposition rate uniformity seen with the absence of argon.
In order to better appreciate and understand the present invention, reference is made to
The substrate has one or more gaps formed between adjacent raised features such as trench 40 shown in
As shown in
To address this issue, some embodiments of the invention deposit a silicon oxide film in a multi-step deposition process as shown in the flowcharts of
Another embodiment of the invention deposits a silicon oxide film in a multi-step deposition process as shown in the flowchart of
The helium-fluent oxide deposition step in employed in step 62 produces considerably more sputtering than a hydrogen-fluent oxide deposition process and thus provides for more redeposition on the sidewalls of trenches in open areas 56 than does a hydrogen-fluent process. For some applications, the additional amount of sidewall redeposition is sufficient to prevent corner clipping that may otherwise occur during the initial deposition stage of a hydrogen-fluent process. Embodiments of the invention switch from the helium-fluent process to the hydrogen-fluent process because the inventors have found that a hydrogen-fluent process has improved gap-fill capabilities as compared to a helium-fluent process for aggressive narrow-width, high aspect ration applications. In some embodiments, the helium-fluent oxide process is used to reduce the height of the gap by between 10-50 percent (as measured from the bottom of the gap) and the hydrogen-fluent process is then used to fill the remaining 50-90 percent of the gap height.
An example of a suitable silicon oxide HDP deposition process that employs helium as the fluent gas in step 62 is set forth in Table 1 below:
Further details of suitable helium-fluent silicon oxide HDP deposition processes can be found in U.S. patent application Ser. No. 10/137,132, entitled “Method for High Aspect Ratio HDP CVD Gap-fill,” filed Apr. 30, 2002, having Zhong Qiang Hua et al. listed as inventors and is hereby incorporated by reference.
In some embodiments the transition between the various deposition steps, including any change in gas flows, chamber pressure, RF power levels and other parameters, is done while a plasma is maintained in the chamber. In other embodiments, however, the plasma is extinguished between steps, gas flows and other parameters are adjusted in preparation for the next step and a plasma is reformed. Embodiments in which the plasma is extinguished can be performed in situ either within a single chamber or in different chambers of a multi-chamber mainframe system or preformed ex situ in different chambers. In some embodiments, in situ processes are preferred for throughput and performance reasons.
Also in some embodiments the progression from a helium-fluent to hydrogen-fluent oxide gap-fill process is gradual.
Embodiments of the invention, including the embodiments discussed with respect to
Exemplary High Density Plasma Chamber
Embodiments of the present invention can be implemented using a variety of high density plasma CVD substrate processing chambers including chambers in which a plasma is formed by the application of RF energy to a coil that at least partially surrounds a portion of the chamber and chambers that use ECR plasma formation techniques. An example of an inductively-coupled HDP-CVD chamber in which embodiments of the method of the present invention can be practiced is set forth below.
The upper portion of chamber 113 includes a dome 114, which is made of a ceramic dielectric material, such as aluminum oxide or aluminum nitride. Dome 114 defines an upper boundary of a plasma processing region 116. Plasma processing region 116 is bounded on the bottom by the upper surface of a substrate 117 and a substrate support 118, which is also made from an aluminum oxide or aluminum ceramic material.
A heater plate 123 and a cold plate 124 surmount, and are thermally coupled to, dome 114. Heater plate 123 and cold plate 124 allow control of the dome temperature to within about ±10° C. over a range of about 100° C. to 200° C. Generally, exposure to the plasma heats a substrate positioned on substrate support 118. Substrate support 118 includes inner and outer passages (not shown) that can deliver a heat transfer gas (sometimes referred to as a backside cooling gas) to the backside of the substrate.
The lower portion of chamber 113 includes a body member 122, which joins the chamber to the vacuum system. A base portion 121 of substrate support 118 is mounted on, and forms a continuous inner surface with, body member 122. Substrates are transferred into and out of chamber 113 by a robot blade (not shown) through an insertion/removal opening (not shown) in the side of chamber 113. Lift pins (not shown) are raised and then lowered under the control of a motor (also not shown) to move the substrate from the robot blade at an upper loading position 157 to a lower processing position 156 in which the substrate is placed on a substrate receiving portion 119 of substrate support 118. Substrate receiving portion 119 includes an electrostatic chuck 120 that can be used to secure the substrate to substrate support 118 during substrate processing.
Vacuum system 170 includes throttle body 125, which houses twin-blade throttle valve 126 and is attached to gate valve 127 and turbo-molecular pump 128. Gate valve 127 can isolate pump 128 from throttle body 125, and can also control chamber pressure by restricting the exhaust flow capacity when throttle valve 126 is fully open. The arrangement of the throttle valve, gate valve, and turbo-molecular pump allow accurate and stable control of chamber pressures as low as about 1 mTorr.
Source plasma system 180A is coupled to a top coil 129 and side coil 130, mounted on dome 114. A symmetrical ground shield (not shown) reduces electrical coupling between the coils. Top coil 129 is powered by top source RF (SRF) generator 131A, whereas side coil 130 is powered by side SRF generator 131B, allowing independent power levels and frequencies of operation for each coil. In a specific embodiment, the top source RF generator 131A provides up to 2,500 watts of RF power at nominally 2 MHz and the side source RF generator 131B provides up to 5,000 watts of RF power at nominally 2 MHz. The operating frequencies of the top and side RF generators may be offset from the nominal operating frequency (e.g. to 1.7-1.9 MHz and 1.9-2.1 MHz, respectively) to improve plasma-generation efficiency.
A bias plasma system 180B includes a bias RF (BRF) generator 131C and a bias matching network 132C. The bias plasma system 180B capacitively couples substrate portion 117 to body member 122, which act as complimentary electrodes. The bias plasma system 180B serves to enhance the transport of plasma species (e.g., ions) created by the source plasma system 180A to the surface of the substrate. In a specific embodiment, bias RF generator provides up to 5,000 watts of RF power at 13.56 MHz.
RF generators 131A and 131B include digitally controlled synthesizers and operate over a frequency range between about 1.8 to about 2.1 MHz. Each generator includes an RF control circuit (not shown) that measures reflected power from the chamber and coil back to the generator and adjusts the frequency of operation to obtain the lowest reflected power, as understood by a person of ordinary skill in the art. Matching networks 132A and 132B match the output impedance of generators 131A and 131B with their respective coils 129 and 130. The RF control circuit may tune both matching networks by changing the value of capacitors within the matching networks to match the generator to the load as the load changes. The RF control circuit may tune a matching network when the power reflected from the load back to the generator exceeds a certain limit. One way to provide a constant match, and effectively disable the RF control circuit from tuning the matching network, is to set the reflected power limit above any expected value of reflected power. This may help stabilize a plasma under some conditions by holding the matching network constant at its most recent condition.
A gas delivery system 133 provides gases from several sources 134(a) . . . 134(n) via gas delivery lines 138 (only some of which are shown). In the particular example illustrated below, gas sources 134(a) . . . 134(n) include separate sources for SiH4, O 2, H2 and NF3 as well as one or more sources for the extended cleaning process. As would be understood by a person of skill in the art, the actual sources used for sources 134(a) . . . 134(n) and the actual connection of delivery lines 138 to chamber 113 varies depending on the deposition and cleaning processes executed within chamber 113. Gas flow from each source 134(a) . . . 134(n) is controlled by one or more flow controllers 135(a) . . . 135(n) as is known to those of skill in the art.
Gases are introduced into chamber 113 through a gas ring 137 and/or a top nozzle 145.
Gas ring 137 also has a plurality of gas nozzles 140 (only one of which is shown), which in a specific embodiment are co-planar with and shorter than source gas nozzles 139, and in one embodiment receive gas from body plenum 141. Gas nozzles 139 and 140 are not fluidly coupled in some embodiments where it is desirable to not mix gases (e.g., SiH4 and O2) introduced through gas ring 137 before injecting the gases into chamber 113. In other embodiments, gases may be mixed prior to injecting the gases into chamber 113 by providing apertures (not shown) between body plenum 141 and gas ring plenum 136. Additional valves, such as 143B (other valves not shown), may shut off gas from the flow controllers to the chamber.
In embodiments where flammable, toxic, or corrosive gases are used, it may be desirable to eliminate gas remaining in the gas delivery lines after a deposition or cleaning process. This may be accomplished using a 3-way valve, such as valve 143B, to isolate chamber 113 from a delivery line 138A and to vent delivery line 138 to vacuum foreline 144, for example. As shown in
Referring again to
A remote plasma cleaning system 150, such as a microwave plasma source or torodial plasma source, is provided to periodically clean deposition residues from chamber components in a dry cleaning operation. The cleaning system includes a remote plasma generator 151 that creates a plasma from one or more cleaning gas source in sources 134(a) . . . 134(n) (e.g., molecular fluorine, nitrogen trifluoride, other perfluorocompound or equivalents alone or in combination with another gas such as argon) in reactor cavity 153. The reactive species resulting from this plasma are conveyed to chamber 113 through cleaning gas feed port 154 via applicator tube 155. The materials used to contain the cleaning plasma (e.g., cavity 153 and applicator tube 155) must be resistant to attack by the plasma. The distance between reactor cavity 153 and feed port 154 should be kept as short as practical, since the concentration of desirable plasma species may decline with distance from reactor cavity 153. Generating the cleaning plasma in a remote cavity does not subject chamber components to the temperature, radiation, or bombardment of the glow discharge that may be present in a plasma formed in situ. Consequently, relatively sensitive components, such as electrostatic chuck 120, do not need to be covered with a dummy wafer or otherwise protected, as may be required with an in situ plasma cleaning process.
System controller 160 controls the operation of system 110 through connections 165. Controller 160 may include, for example, a memory 162, such as a hard disk drive and/or a floppy disk drive and a card rack coupled to a processor 161. The card rack may contain a single-board computer (SBC), analog and digital input/output boards, interface boards and stepper motor controller boards. System controller 160 operates under the control of a computer program stored on the hard disk drive or through other computer programs, such as programs stored on a removable disk. The computer program dictates, for example, the timing, mixture of gases, RF power levels and other parameters of a particular process.
Table 2 below lists the process parameters according to a multistep helium-fluent followed by hydrogen-fluent HDP silicon oxide deposition process according to one embodiment of the invention implemented in the Ultima HDP-CVD chamber manufactured for Applied Materials and outfitted for 200 mm substrates. The gas flow rates and other parameters set forth in Table 2 (and used in other examples set forth in this application) are optimized for a deposition process run in the Ultima chamber. A person of ordinary skill in the art will recognize that these rates and parameters are in part chamber specific and will vary if chambers of other design and/or volume are employed.
In some particular embodiments, the flow of molecular hydrogen is introduced from both nozzles surrounding the periphery of the substrate and at least one nozzle positioned above the substrate pointing downwards towards the substrate surface. The inventors have found that such an arrangement may enable deposition of a film having improved uniformity characteristics as opposed to introducing the molecular hydrogen flow from either one or more nozzles above the substrate or one or more nozzles surrounding the substrate. Also, in some embodiments, SiH4 and O2 are introduced from separate, non-fluidicly coupled nozzles sets, such as nozzles 139 and 140, positioned around the substrate. Additionally, these embodiments may also introduce a flow of silane from a nozzle above the substrate, such as nozzle 141. Having been so described, the optimization of a particular flow rate of a fluent or precursor gas from a side nozzle or top nozzle can readily be determined by a person of skill in the art.
In order to better appreciate the benefit achievable by the method of the invention reference is now made to
Having fully described several embodiments of the present invention, many other equivalents or alternative embodiments of the present invention will be apparent to those skilled in the art. For example, while the invention described with respect to an undoped silicate glass layer, the invention can also be used to improve the gap-fill capabilities of phosphosilicate glass (PSG), boron-doped silicate glass (BSG) and boron phosphosilicate glass (BPGS) layers as well as other types of materials by adding an appropriate dopant gas such as PH3 for PSG or, B2H6 for BSG in one or more of the film deposition steps. Also, in other embodiments, an oxygen source such as N2O or CO2 can be used instead of O2 and a silicon source other than monosilane may be used. Examples of suitable silicon sources include other silane family members such as, Si2H6, Si3H8, etc.; TEOS or SiF4 among others. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents.
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