Method and apparatus for minimizing seam effects during deposition of teos oxide films

Abstract

The present invention relates to a method and apparatus for minimizing seam effects of a TEOS oxide film deposited during a trench fill process performed on a semiconductor substrate in a semiconductor substrate plasma processing apparatus. A method for minimizing seam effects of a TEOS oxide film deposited during a trench fill process performed on a semiconductor substrate in a semiconductor substrate plasma processing apparatus includes supporting the semiconductor substrate on a pedestal in a vacuum chamber of the semiconductor substrate plasma processing apparatus. A process gas including TEOS, an oxidizer, and argon is flowed through a faceplate of a showerhead assembly into a processing region of the vacuum chamber. RF energy energizes the process gas into a plasma in which a TEOS oxide film is deposited on the semiconductor substrate to fill at least one trench thereof. The argon is supplied in an amount sufficient to increase an electron density of the plasma such that a deposition rate of the TEOS oxide film toward a center of the semiconductor substrate is increased and seam effects of the TEOS oxide film deposited in the at least one trench are reduced.

Description

[0001] This application is a divisional application of application No. 201610127551.3, filed on March 7, 2016, entitled "Method and apparatus for minimizing seam effect during TEOS oxide film deposition". TECHNICAL FIELD

[0002] The disclosed embodiments relate to methods and apparatus for depositing dielectric films on semiconductor substrates during semiconductor substrate processing, and more particularly to methods and apparatus for minimizing seam effect during TEOS oxide film deposition. BACKGROUND

[0003] TEOS (tri-ethoxy-organosilicate) is a silicon-containing compound that is a liquid at room temperature. TEOS is used in many applications to deposit dielectric films on substrates, for example, in place of silane. TEOS is used in applications where conformality is desired because the silicon dioxide (or "TEOS oxide") film deposited from a TEOS chemical vapor deposition process has good conformality. TEOS oxide is typically deposited from a plasma enhanced deposition chemical vapor deposition (PECVD) process.

[0004] TEOS-based PECVD processes typically involve exposing a substrate to a process gas that includes TEOS and an oxidizer such as oxygen or ozone. TEOS oxide deposition during a trench fill process of semiconductor substrate processing can result in non-uniform deposition and formation of step coverage, which can result in the formation of voids and / or seams (i.e., seam effect) in the deposited film due to overhangs of deposited material on the sidewalls of the trench. Thus, it is desirable to have a process for depositing TEOS oxide films with high deposition rate, high purity, in which defects such as seam effect are minimized. SUMMARY

[0005] Disclosed is a method of minimizing seam effects of a TEOS oxide film deposited during a trench fill process on a semiconductor substrate in a semiconductor substrate plasma processing apparatus. The method includes supporting a semiconductor substrate on a pedestal in a vacuum chamber of a semiconductor substrate plasma processing apparatus, wherein the semiconductor substrate includes at least one trench on an upper surface thereof. A process gas including TEOS, an oxidizer, and argon is flowed through a faceplate of a showerhead assembly of the semiconductor substrate plasma processing apparatus into a processing region of the vacuum chamber above an upper surface of the semiconductor substrate. RF energy is supplied to the processing region of the vacuum chamber with at least one RF generator to excite the process gas into a plasma, wherein a TEOS oxide film is deposited on the upper surface of the semiconductor substrate so as to fill the at least one trench, wherein the argon is supplied in an amount sufficient to increase an electron density of the plasma such that a deposition rate of the TEOS oxide film toward a center of the semiconductor substrate is increased and seam effects of the TEOS oxide film deposited in the at least one trench are reduced.

[0006] Also disclosed is a showerhead assembly of a semiconductor substrate plasma processing apparatus. The showerhead assembly includes a faceplate including a lower wall and an annular outer wall extending upwardly from an outer periphery of the lower wall, and a backplate, wherein an outer periphery of the backplate is welded to an upwardly extending annular wall of the backplate such that a cavity is formed between the lower wall of the faceplate and the backplate. The lower wall of the faceplate includes at least 6000 gas injection holes extending therethrough, wherein the at least 6000 gas injection holes are spatially arranged in the lower wall of the faceplate such that a process gas is delivered to the cavity and injected through the at least 6000 gas injection holes to minimize seam effects of a TEOS oxide film deposited in at least one trench of a semiconductor substrate during a TEOS oxide trench fill operation. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 A schematic of a semiconductor substrate processing apparatus operable to perform a method of depositing a TEOS oxide film as disclosed herein is shown.

[0008] Figure 2A A result of a TEOS oxide deposition process performed on a DRAM cell feature of a semiconductor substrate of the prior art is shown.

[0009] Figure 2B A result of a TEOS oxide deposition process performed on a DRAM cell feature of a semiconductor substrate according to one embodiment disclosed herein is shown.

[0010] Figure 3A An angle of a seam formed as a result of a TEOS oxide deposition process on a DRAM cell feature of a semiconductor substrate of the prior art is shown.

[0011] Figure 3B An angle of a formed seam is shown as a result of a TEOS oxide deposition process on DRAM cell features of a semiconductor substrate performed in accordance with an embodiment of the present disclosure.

[0012] Figure 4A and Figure 4B An embodiment of a showerhead assembly of a semiconductor substrate plasma processing apparatus in accordance with an embodiment of the present disclosure is shown

[0013] Figure 5A An embodiment of a faceplate of a showerhead assembly of a semiconductor substrate plasma processing apparatus in accordance with an embodiment of the present disclosure is shown, Figure 5B An enlarged view of detail J is shown Figure 5A DETAILED DESCRIPTION

[0014] In the following detailed description, exemplary embodiments are set forth in order to provide a thorough understanding of the disclosed devices and methods. However, it will be apparent to one skilled in the art that the exemplary embodiments can be practiced without these specific details or by using alternative elements or methods. In other instances, well-known processing, procedures and / or components have not been described in detail in order to avoid unnecessarily obscuring aspects of the embodiments. Like reference numerals refer to like elements throughout the description. As used herein, the term "about" refers to ±10%.

[0015] Triethoxysilicate ("TEOS") is a silicon-containing compound that is a liquid at room temperature and is used in many applications to deposit TEOS oxide films on semiconductor substrates in semiconductor substrate plasma processing apparatuses. TEOS is often used in place of silane for applications requiring good conformality, such as when the semiconductor substrate surface contains recessed features or other irregularities.

[0016] Silicon dioxide films deposited using TEOS (also referred to as TEOS oxide films or TEOS films) can be deposited by a plasma-enhanced chemical vapor deposition process or a plasma-enhanced atomic layer deposition process using a process gas containing TEOS and an oxidizer, typically oxygen or ozone.

[0017] ​Embodiments of the disclosed methods can be carried out in a plasma enhanced chemical vapor deposition (PECVD) reactor, or alternatively in a plasma enhanced atomic layer deposition (PEALD) reactor. Such reactors can take many different forms. The apparatus can include one or more vacuum chambers (chambers) or "reactors" (sometimes including multiple stations), each of which can hold one or more semiconductor substrates and is suitable for plasma processing of the semiconductor substrates. The chamber or chambers hold the semiconductor substrates in a defined position or positions (with or without motion within the position, such as rotation, vibration, or other agitation). In one embodiment, the semiconductor substrates undergoing deposition processing during processing are transported from one station to another within the reactor chamber. For example, if a 2000 Angstrom film is desired on the top surface of a semiconductor substrate, then each of four stations in accordance with embodiments of the disclosed application can deposit a 500 Angstrom film on the top surface of the semiconductor substrate. Alternatively, TEOS oxide film deposition can all be carried out in a single station or can deposit any fraction of the total film thickness in any number of stations.

[0018] During processing, each semiconductor substrate is held in place by a pedestal (i.e., semiconductor substrate support), electrostatic chuck, and / or other substrate holding device. For certain operations in which the semiconductor substrate is heated, the substrate support or pedestal can include a heater such as a heated plate.

[0019] Figure 1A simplified block diagram depicting various reactor components arranged for implementing embodiments as disclosed herein is provided. As shown, a semiconductor substrate plasma processing apparatus 300 includes a vacuum chamber 324 that encloses other components of the reactor and is used to contain the plasma generated by a capacitor-type system that includes a showerhead assembly 314 that operates in conjunction with a grounded heater block 320. At least one RF generator is operable to supply RF energy into a processing region above an upper surface of a semiconductor substrate 316 in the vacuum chamber 324 to energize a process gas supplied into the processing region of the vacuum chamber 324 into a plasma so that a plasma deposition process can be performed in the vacuum chamber 324. For example, each of a high frequency RF generator 302 and a low frequency RF generator 304 can be connected to a matching network 306 that is connected to the showerhead assembly 314 so that RF energy can be provided to the processing region above the semiconductor substrate 316 in the vacuum chamber 324. The power and frequency of the RF energy supplied to the interior of the vacuum chamber 324 by the matching network 306 is sufficient to generate a plasma from the process gas. In one embodiment, the high frequency RF generator 302 operates at a frequency of about 2-60 MHz, and in a preferred embodiment, the high frequency RF generator 302 operates at a frequency of about 13.56 MHz. In one embodiment, the high frequency RF generator 302 has a power of about 1100 W to 1700 W. In one embodiment, the low frequency RF generator 304 operates at a frequency of about 50 to 800 kHz, preferably about 300 to 500 kHz, and the low frequency RF generator 304 has a power of about 1550 to 2400 W.

[0020] In the reactor, a semiconductor substrate pedestal 318 supports the semiconductor substrate 316. The pedestal can include a chuck, a fork, or lift pins to hold and transport the semiconductor substrate during and between deposition and / or plasma processing processes. The chuck can be an electrostatic chuck, a mechanical chuck, a vacuum chuck, or various other types of chucks as can be used for industrial and / or research purposes. Details of a lift pin assembly for a pedestal including an electrostatic chuck can be found in commonly assigned U.S. Patent No. 8,840,754, the entire contents of which are incorporated herein by reference.

[0021] Process gases are introduced into the vacuum chamber 324 via the inlet 312 and the showerhead assembly 314. A plurality of source gas lines 310 may be connected to the heated manifold 308. The gases may or may not be premixed. Appropriate valves and mass flow control mechanisms are used to ensure that the appropriate gases are delivered during plasma deposition. When the chemical precursor is delivered in liquid form (e.g., liquid TEOS), a liquid flow control mechanism (e.g., a liquid precursor delivery system 341 and a liquid supply line 301) may be used to control the flow rate of the supplied liquid precursor, wherein the liquid supplied by the liquid precursor delivery system 341 is heated above its vaporization point during its delivery to the heated manifold or in the heated manifold 308 and during mixing with other process gases in the heated manifold 308, wherein the process gas including the vaporized liquid precursor (e.g., vaporized TEOS) is supplied to the vacuum chamber 324 through the showerhead assembly 314, and plasma deposition is subsequently performed in the vacuum chamber 324. The flow rate of the liquid precursor (e.g., liquid TEOS) before vaporization corresponds to the amount of the subsequently vaporized precursor delivered to the vacuum chamber. Details of liquid precursor delivery systems for deposition apparatus may be found in commonly assigned US Patent No. 8,017,527, the entire contents of which are incorporated herein by reference.

[0022] The process gas may exit the vacuum chamber 324 via an outlet 322. A vacuum pump 326 (e.g., a one- or two-stage mechanical dry pump and / or a turbomolecular pump) may draw the process gas out of the vacuum chamber 324 through a closed-loop controlled flow restriction device (e.g., a throttle valve or a pendulum valve) and maintain a suitable low pressure within the vacuum chamber 324. Preferably, the pressure in the vacuum chamber 324 is maintained at approximately 3-5 Torr, or approximately 4 Torr, during TEOS oxide film deposition.

[0023] As mentioned above, one of the issues to be considered for liquid-based PECVD and / or PEALD processes is the formation of non-uniform deposition and / or step coverage during the trench filling process, such as the TEOS oxide deposition process for forming the TEOS oxide layer 100. For example, Figure 2A As shown, the prior art TEOS oxide deposition process produces severe "over-overhang" deposition of TEOS oxide material on the sidewalls 103 of the trench 102 filled with the TEOS oxide material of the TEOS oxide layer 100 of the DRAM cell feature of the semiconductor substrate 50. The severe "over-overhang" leads to the formation of "fang"-shaped portions 105 and sharp seam corners 104 in the TEOS oxide material of the TEOS oxide layer 100 in the DRAM cell structure, for example, where subsequent processing (such as a wet cleaning process) may cause voids, cracks, and device failure.

[0024] Embodiments of the methods and apparatus disclosed herein minimize seam effects of TEOS oxide deposition during a trench fill process, such as a trench fill process in the course of forming DRAM cell features of a semiconductor substrate. For example, Figure 2B A processed semiconductor substrate 250 that has been processed according to embodiments disclosed herein on an apparatus according to embodiments disclosed herein is shown after a trench fill process and a wet clean process have been performed on the semiconductor substrate 250. As shown, Figure 2B The DRAM cell structure of the semiconductor substrate 250 does not have sharp seam corners as a result of seam effects of the deposited TEOS oxide material of the TEOS oxide layer 200 having been minimized and "fangs" have not been formed in the material of the deposited TEOS oxide layer 200, as shown. The thickness of the deposited TEOS oxide layer 200 is about 23,500 Angstroms, as shown. Figure 2B The deposited TEOS oxide layer 200 is uniform across the cell features and seam effects are reduced (minimized) (i.e., seam angles are reduced, which act as nucleation points for crack propagation and void formation), as shown.

[0025] In one embodiment, a method of depositing TEOS oxide includes providing a semiconductor substrate into a vacuum chamber of a semiconductor substrate plasma processing apparatus, such as a PECVD or PEALD apparatus. The semiconductor substrate is preferably a semiconductor wafer having a diameter of at least about 300 millimeters. An example of the application of the TEOS oxide film is described below. Process gases including TEOS in vapor form (TEOS gas), an oxidizer, helium, and argon are then introduced into the vacuum chamber. Examples of the oxidizer can include oxygen and ozone. The process gases can also include one or more dopant gases, including carbon dioxide. The TEOS oxide film can then be deposited on the substrate surface by a PECVD or PEALD reaction at a high deposition rate.

[0026] The initial deposition rate is preferably at least about 7000 Angstroms per minute. In one embodiment, the initial deposition rate is at least about 8000 Angstroms per minute, about 9000 Angstroms per minute, 9500 Angstroms per minute, 9700 Angstroms per minute, and 10000 Angstroms per minute. As the film builds up on the substrate, the deposition rate increases; for a substrate on which a thick layer of film has built up, the deposition rate can be about 20000-30000 Angstroms per minute. To deposit the film at a high deposition rate, the flow rate of the liquid TEOS and oxidant (in gaseous form) is high. For example, the flow rate of the liquid TEOS prior to vaporization can range from about 11-17 milliliters per minute. In particular embodiments, the flow rate of the liquid TEOS prior to vaporization can be at least about 13 milliliters per minute, 14 milliliters per minute, or 15 milliliters per minute. Preferably, the flow rate of the liquid TEOS prior to vaporization is about 14 milliliters per minute. The oxidant can be O2or ozone, with the oxidant preferably being O2. The flow rate of the oxidant can range from about 15200 seem to 23000 seem, or in particular embodiments from about 18000-20000 seem, preferably 19000 seem.

[0027] According to various embodiments, the helium flow rate ranges from about 1000-5000 seem, and from about 3,000-5,000 seem, or in certain embodiments from about 3500-4500 seem, preferably about 4000 seem. The addition of helium to the process gas mixture increases the number of electrons (i.e., electron density) and plasma density in the plasma toward the periphery of the processing region above the upper surface of the semiconductor substrate, so as to increase the deposition rate of the TEOS oxide toward the periphery of the semiconductor substrate during processing. Further benefits of adding helium to the process gas mixture are discussed in commonly assigned U.S. Patent No. 7,923,376, the entire contents of which are incorporated herein by reference.

[0028] According to various embodiments, the argon flow rate ranges from about 2000 to 6000 seem, or from about 3000 to 5000 seem. If the argon in the process gas mixture increases the number of electrons (i.e., electron density) and plasma density in the plasma toward the center of the processing region above the upper surface of the semiconductor substrate, so as to increase the deposition rate of the TEOS oxide toward the center of the semiconductor substrate during processing. Thus, by controlling the respective flow rates of argon and helium in the process gas mixture, the deposition rate of the TEOS oxide film across the upper surface of the semiconductor substrate can be controlled, so that the seam effect of the TEOS oxide film deposited in the trench formed in the upper surface of the semiconductor can be minimized.

[0029] The total flow rate of the process gases in the vacuum chamber and other conditions can vary depending on, among other things, the RF power, chamber pressure, substrate surface temperature, and size of the substrate. The flow rates described above are for a 300 mm semiconductor wafer; those skilled in the art will appreciate that the flow rates can be adjusted for PECVD TEOS oxide at high deposition rates on substrates of 200 mm or 450 mm size or larger (e.g., substrates for flat panel devices). The substrate temperature is about 300° C to 550° C, preferably about 375° C, with a temperature non-uniformity across the substrate preferably less than 2° C.

[0030] Applications of the PECVD TEOS oxide film can include trench fill operations, interlayer dielectrics, inter-dielectric gap fill, gate dielectrics, barrier layers, and cap layers. As described above, the silicon oxide film deposited with TEOS has improved conformality and step coverage when the process gas includes argon in a PECVD process that does not use argon. In addition, embodiments of the disclosed method can be combined with other processes; for example, a PECVD TEOS gap fill process can alternate with a sputter etch step.

[0031] The relative flow rates of the reactant gases, as well as the RF power, can depend on the desired properties of the deposited film. For example, in some applications, a tensile film is desired. The etch selectivity is controlled by the film stress. Thus, the film stress can be controlled to set the etch selectivity for a given application. Preferably, the deposited film can have a tensile film stress of between about 0 and 150 MPa; in some embodiments, at least 50 MPa.

[0032] In various embodiments, such as in trench fill applications, a film with a high compressive film stress is desired. Preferably, the resulting film can have a compressive film stress of between about 150 and 400 MPa.

[0033] Figure 3A An embodiment of a prior art deposition trench fill process for a TEOS oxide film on a semiconductor substrate is shown, with a liquid TEOS flow rate of 14 ml / min prior to vaporization, a helium flow rate of 1000 seem, and an O2 flow rate of 15000 seem. During deposition, the vacuum chamber is maintained at about 2.4 Torr, the high frequency RF generator is powered at about 250 W, and the low frequency RF generator is powered at about 2220 W. As shown, there is a seam effect, with the deposited TEOS oxide film having a seam angle of about 60 degrees, with a crack in the deposited material after a wet clean process has been performed on the semiconductor substrate. Figure 3A

[0034] According to one preferred embodiment of the disclosed method, and as shown in Figure 3B ​As shown, as the seam angle of the deposited material has been reduced to approximately 55 degrees, the seam effect has been minimized. In this embodiment, no cracks were formed in the deposited material after the wet cleaning process. To minimize the seam effect, the plasma deposition process included a flow rate of approximately 14 ml / min of liquid TEOS before vaporization, a helium flow rate of approximately 4,000 sccm, an argon flow rate of 3,000 sccm, and an O2 flow rate of 19,000 sccm. During the deposition process, the vacuum chamber was maintained at approximately 4 Torr, the high-frequency RF generator was powered at approximately 1,400 W, and the low-frequency RF generator was powered at approximately 1,950 W.

[0035] Figure 4A and 4B One embodiment of a showerhead assembly 314 that can be used in accordance with embodiments of the disclosed methods is shown. The showerhead assembly 314 includes a rod 404, a backing plate 406, and a faceplate 410. The faceplate 410 preferably includes a lower wall 421 and an annular wall 422 extending upwardly from the periphery of the lower wall 421. The lower wall 421 includes a plasma exposed surface 424. The diameter of the plasma exposed surface 424 of the faceplate 410 can be slightly larger than the diameter of the semiconductor substrate supported below the plasma exposed surface 424 of the faceplate 410, preferably about 100% to 125% of the diameter of the semiconductor substrate. For example, for a 300 mm (12 inch) diameter semiconductor substrate, the diameter of the plasma exposed surface 424 of the faceplate 410 can be about 13 to 15 inches.

[0036] The lower wall 421 of the face plate 410 and the back plate 406 can each have a thickness of about 0.125 to 0.5 inches, or about 0.25 to 0.5 inches, or about 0.25 to 0.375 inches. Preferably, the thickness of the lower wall 421 of the face plate 410 is 0.375 inches so that a minimal thermal gradient is formed across the plasma exposed surface 424 of the face plate 410. The face plate 410 can be made of aluminum or an aluminum alloy, anodized or coated aluminum, or other metals formulated to withstand high temperatures, chemicals, and plasma. The back plate 406 can be made of aluminum or an aluminum alloy, anodized or coated aluminum, or other metals formulated to withstand high temperatures, chemicals, and plasma.

[0037] In one embodiment, the backplate 406 is about 0.5 inches thick and the lower wall 421 of the faceplate 410 is about 0.375 inches thick. The backplate 406 cooperates with the upwardly extending annular wall 422 of the faceplate 410 such that a cavity 408 is formed between the lower wall 421 of the faceplate 410 and the backplate 406. Preferably, the backplate 406 is welded to the upwardly extending annular wall 422 of the faceplate 410 so as to integrally couple the faceplate 410 to the backplate 406. In an alternative embodiment, screws can be used to detachably couple the faceplate 410 to the backplate 406.

[0038] The stem 404 extends upwardly from the backplate 406 of the showerhead assembly 314. In one embodiment, the lower end of the stem 404 can be welded to the backplate 406. The reactant gas is introduced through the gas inlet passage 402 in the stem 404, flows through the backplate 406, and enters the cavity 408 between the backplate 406 and the faceplate 410. A baffle 412 disposed in the cavity 408 distributes the gas evenly throughout the cavity 408. The baffle 412 can be attached to the backplate 406 by threaded inserts or threaded holes (not shown) in the baffle 412 and a number of screws, or alternatively, the baffle 412 can be welded to the backplate 406.

[0039] The volume of the cavity 408 is defined by the gap between the backplate 406 and the faceplate 410. The gap can be about 0.5 to 1 inch, and preferably about 0.75 inches. To maintain a uniform gas flow in the gap, the size of the gap can be kept constant at a number of locations (e.g., 3, 6, or up to 10 locations) by a number of posts 440 located between the backplate 406 and the faceplate 410. Preferably, the faceplate 410 includes the posts 440 integrally formed therein, and the backplate 406 includes corresponding openings 441 configured to receive the upper ends of the posts 440 when the backplate 406 is coupled to the faceplate 410. Preferably, the upper ends of the posts 440 are welded to the backplate 406. The faceplate 410 includes gas ejection holes 444 (see Figure 5A ) such that process gas delivered into the cavity 408 of the showerhead assembly 314 can be ejected through the gas ejection holes 444 into a processing region above the semiconductor substrate, and material such as TEOS oxide film can also be deposited on the upper surface of the semiconductor substrate below the plasma exposed surface 424 of the lower wall 421 of the faceplate 410 of the showerhead assembly 314.

[0040] Figure 5A An embodiment of the plasma exposed surface 424 of the lower wall 421 of the faceplate 410 of the showerhead assembly 314 (see Figure 4B ) according to the disclosed embodiments is shown. Figure 5B An enlarged view of Detail J of Figure 5A is shown. As Figure 5AAs shown, the faceplate 410 includes a plurality of gas injection holes 444 or openings, each of which extends through the thickness of the lower wall 421 of the faceplate 410 such that process gas can be supplied (injected) through the faceplate 410. The gas injection holes 444 are spatially arranged in the lower wall 421 of the faceplate 410 such that uniform deposition can be achieved across the entire upper surface of a semiconductor substrate when processing the semiconductor substrate according to one embodiment of the method disclosed herein. In one embodiment, at least 6000 gas injection holes 444 are spatially arranged in the lower wall of the faceplate 410 such that process gas is delivered to the chamber 408 (see Fig. 1) and injected through the at least 6000 gas injection holes 444, thereby minimizing seam effects of a TEOS oxide film deposited in at least one trench of a semiconductor substrate during a TEOS oxide trench fill operation. Figure 4B ) and injected through the at least 6000 gas injection holes 444, thereby minimizing seam effects of a TEOS oxide film deposited in at least one trench of a semiconductor substrate during a TEOS oxide trench fill operation.

[0041] The gas injection holes 444 can be machined, ground or drilled. Each of the gas injection holes 444 can have a diameter of about 0.01 to 0.5 inches, with a preferred diameter of about 0.04 inches. Alternatively, the gas injection holes 444 can include smaller diameter holes and larger diameter holes. In one embodiment, some of the gas injection holes 444 can have different sizes. For example, the faceplate can include an optional central gas injection hole 444a (see Fig. 4) in which the central gas injection hole 444b has a diameter that is greater than, equal to or less than the diameter of the remaining gas injection holes 444. In one embodiment, each of the gas injection holes 444 in a row of concentric gas injection holes has the same diameter, or alternatively, the gas injection holes 444 in a row of concentric gas injection holes have a diameter that is greater than or less than an adjacent row of concentric gas injection holes. In a preferred embodiment, the faceplate 410 includes a central gas injection hole 444a in which the central gas injection hole 444a has a diameter of about 0.02 inches, while each of the remaining gas injection holes 444 surrounding the central gas injection hole 444a has a diameter of about 0.04 inches. Figure 5B

[0042] The arrangement of the gas injection holes 444 and the respective diameter of each of the gas injection holes 444, including the optional central gas injection hole 444a, controls the distribution of process gas supplied through the faceplate 410, thereby controlling the residence time of the composition of process gas flowing across the entire upper surface of a semiconductor substrate. In one embodiment, the faceplate 410 includes at least about 6000 gas injection holes 444. The gas injection holes 444 are arranged in rows of concentric holes about the center of the faceplate 410, wherein preferably the distance between adjacent gas injection holes 444 in each row of concentric gas injection holes is equally spaced about the center of the faceplate 410.

[0043] ​Preferably, the faceplate 410 includes a central gas ejection aperture 444a (see Figure 5B ) and a plurality of concentric rows of gas ejection apertures 444 surrounding the central gas ejection aperture 444a. In one embodiment, the faceplate 410 does not include a central gas ejection aperture 444a.

[0044] In one embodiment, as shown in Figure 5A the faceplate 410 includes an optional central gas ejection aperture 444a (see Figure 5B) of 45 rows of concentric gas injection orifices 444, wherein a first row of concentric orifices has 9 gas injection orifices located at a radial distance of about 0.1-0.2 inches from the center of the faceplate 410, a second row of concentric orifices has 16 gas injection orifices located at a radial distance of about 0.2-0.3 inches from the center of the faceplate 410, a third row of concentric orifices has 21 gas injection orifices located at a radial distance of about 0.4-0.5 inches from the center of the faceplate 410, a fourth row of concentric orifices has 27 gas injection orifices located at a radial distance of about 0.5-0.6 inches from the center of the faceplate 410, a fifth row of concentric orifices has 34 gas injection orifices located at a radial distance of about 0.6-0.7 inches from the center of the faceplate 410, a sixth row of concentric orifices has 44 gas injection orifices located at a radial distance of about 0.7-0.8 inches from the center of the faceplate 410, a seventh row of concentric orifices has 49 gas injection orifices located at a radial distance of about 0.9-1 inch from the center of the faceplate 410, an eighth row of concentric orifices has 56 gas injection orifices located at a radial distance of about 1-1.1 inches from the center of the faceplate 410, a ninth row of concentric orifices has 62 gas injection orifices located at a radial distance of about 1.1-1.2 inches from the center of the faceplate 410, a tenth row of concentric orifices has 70 gas injection orifices located at a radial distance of about 1.25-1.35 inches from the center of the faceplate 410, an eleventh row of concentric orifices has 83 gas injection orifices located at a radial distance of about 1.4-1.5 inches from the center of the faceplate 410, a twelfth row of concentric orifices has 86 gas injection orifices located at a radial distance of about 1.5-1.6 inches from the center of the faceplate 410, a thirteenth row of concentric orifices has 95 gas injection orifices located at a radial distance of about 1.7-1.8 inches from the center of the faceplate 410, a fourteenth row of concentric orifices has 97 gas injection orifices located at a radial distance of about 1.8-1.9 inches from the center of the faceplate 410, a fifteenth row of concentric orifices has 107 gas injection orifices located at a radial distance of about 1.9-2 inches from the center of the faceplate 410, a sixteenth row of concentric orifices has 118 gas injection orifices located at a radial distance of about 2.05-2.15 inches from the center of the faceplate 410, a seventeenth row of concentric orifices has 116 gas injection orifices located at a radial distance of about 2.2-2.3 inches from the center of the faceplate 410, an eighteenth row of concentric orifices has 127 gas injection orifices located at a radial distance of about 2.3-2.4 inches from the center of the faceplate 410, a nineteenth row of concentric orifices has 127 gas injection orifices located at a radial distance of about 2.4-2.5 inches from the center of the faceplate 410, a twentieth row of concentric orifices has 139 gas injection orifices located at a radial distance of about 2.55-2.65 inches from the center of the faceplate 410, a twenty-first row of concentric orifices has 151 gas injection orifices located at a radial distance of about 2.7-2.8 inches from the center of the faceplate 410, a twenty-second row of concentric orifices has 163 gas injection orifices located at a radial distance of about 2.9-3 inches from the center of the faceplate 410, a twenty-third row of concentric orifices has 175 gas injection orifices located at a radial distance of about 3.1-3.2 inches from the center of the faceplate 410, a twenty-fourth row of concentric orifices has 187 gas injection orifices located at a radial distance of about 3.3-3.4 inches from the center of the faceplate 410, a twenty-fifth row of concentric orifices has 199 gas injection orifices located at a radial distance of about 3.5-3.6 inches from the center of the faceplate 410, and a twenty-sixth row of concentric orifices has 211 gas injection orifices located at a radial distance of about 3.7-3.8 inches from the center of the faceplate 410.7-2.8 inches radial distance, the twenty-second concentric row of holes has 162 gas injection holes located at a radial distance of about 2.8-2.9 inches from the center of the faceplate 410, the twenty-third concentric row of holes has 165 gas injection holes located at a radial distance of about 3-3.1 inches from the center of the faceplate 410, the twenty-fourth concentric row of holes has 171 gas injection holes located at a radial distance of about 3.1-3.2 inches from the center of the faceplate 410, the twenty-fifth concentric row of holes has 170 gas injection holes located at a radial distance of about 3.2-3.3 inches from the center of the faceplate 410, the twenty-sixth concentric row of holes has 178 gas injection holes located at a radial distance of about 3.35-3.45 inches from the center of the faceplate 410, the twenty-seventh concentric row of holes has 186 gas injection holes located at a radial distance of about 3.5-3.6 inches from the center of the faceplate 410, the twenty-eighth concentric row of holes has 185 gas injection holes located at a radial distance of about 3.6-3.7 inches from the center of the faceplate 410, the twenty-ninth concentric row of holes has 195 gas injection holes located at a radial distance of about 3.75-3.85 inches from the center of the faceplate 410, the thirtieth concentric row of holes has 195 gas injection holes located at a radial distance of about 3.9-4 inches from the center of the faceplate 410, the thirty-first concentric row of holes has 200 gas injection holes located at a radial distance of about 4-4.1 inches from the center of the faceplate 410, the thirty-second concentric row of holes has 202 gas injection holes located at a radial distance of about 4.15-4.25 inches from the center of the faceplate 410, the thirty-third concentric row of holes has 205 gas injection holes located at a radial distance of about 4.3-4.4 inches from the center of the faceplate 410, the thirty-fourth concentric row of holes has 210 gas injection holes located at a radial distance of about 4.4-4.5 inches from the center of the faceplate 410, the thirty-fifth concentric row of holes has 214 gas injection holes located at a radial distance of about 4.5-4.6 inches from the center of the faceplate 410, the thirty-sixth concentric row of holes has 215 gas injection holes located at a radial distance of about 4.7-4.8 inches from the center of the faceplate 410, the thirty-seventh concentric row of holes has 212 gas injection holes located at a radial distance of about 4.8-4.9 inches from the center of the faceplate 410, the thirty-eighth concentric row of holes has 212 gas injection holes located at a radial distance of about 4.9-5 inches from the center of the faceplate 410, the thirty-ninth concentric row of holes has 214 gas injection holes located at a radial distance of about 5.1-5.2 inches from the center of the faceplate 410, the fortieth concentric row of holes has 212 gas injection holes located at a radial distance of about 5.2-5.3 inches from the center of the faceplate 410, the forty-first concentric row of holes has 210 gas injection holes located at a radial distance of about 5.3-5.4 inches from the center of the faceplate 410, the forty-second concentric row of holes has 208 gas injection holes located at a radial distance of about 5.4-5.5 inches from the center of the faceplate 410, the forty-third concentric row of holes has 206 gas injection holes located at a radial distance of about 5.5-5.6 inches from the center of the faceplate 410, the forty-fourth concentric row of holes has 204 gas injection holes located at a radial distance of about 5.6-5.7 inches from the center of the faceplate 410, the forty-fifth concentric row of holes has 202 gas injection holes located at a radial distance of about 5.7-5.8 inches from the center of the faceplate 410, the forty-sixth concentric row of holes has 200 gas injection holes located at a radial distance of about 5.8-5.9 inches from the center of the faceplate 410, the forty-seventh concentric row of holes has 198 gas injection holes located at a radial distance of about 5.9-6 inches from the center of the faceplate 410, the forty-eighth concentric row of holes has 196 gas injection holes located at a radial distance of about 6.1-6.2 inches from the center of the faceplate 410, the forty-ninth concentric row of holes has 194 gas injection holes located at a radial distance of about 6.2-6.3 inches from the center of the faceplate 410, the fiftieth concentric row of holes has 192 gas injection holes located at a radial distance of about 6.3-6.4 inches from the center of the faceplate 410, the fifty-first concentric row of holes has 190 gas injection holes located at a radial distance of about 6.4-6.5 inches from the center of the faceplate 410, the fifty-second concentric row of holes has 188 gas injection holes located at a radial distance of about 6.5-6.6 inches from the center of the faceplate 410, the fifty-third concentric row of holes has 186 gas injection holes located at a radial distance of about 6.6-6.7 inches from the center of the faceplate 410, the fifty-fourth concentric row of holes has 184 gas injection holes located at a radial distance of about 6.7-6.8 inches from the center of the faceplate 410, the fifty-fifth concentric row of holes has 182 gas injection holes located at a radial distance of about 6.8-6.9 inches from the center of the faceplate 410, the fifty-sixth concentric row of holes has 180 gas injection holes located at a radial distance of about 6.9-7 inches from the center of the faceplate 410, the fifty-seventh concentric row of holes has 178 gas injection holes located at a radial distance of about 7.1-7.2 inches from the center of the faceplate 410, the fifty-eighth concentric row of holes has 176 gas injection holes located at a radial distance of about 7.2-7.3 inches from the center of the faceplate 410, the fifty-ninth concentric row of holes has 174 gas injection holes located at a radial distance of about 7.3-7.4 inches from the center of the faceplate 410, the sixtieth concentric row of holes has 172 gas injection holes located at a radial distance of about 7.4-7.5 inches from the center of the faceplate 410, the sixty-first concentric row of holes has 170 gas injection holes located at a radial distance of about 7.5-7.6 inches from the center of the faceplate 410, the sixty-second concentric row of holes has 168 gas injection holes located at a radial distance of about 7.6-7.7 inches from the center of the faceplate 410, the sixty-third concentric row of holes has 166 gas injection holes located at a radial distance of about 7.7-7.8 inches from the center of the faceplate 410, the sixty-fourth concentric row of holes has 164 gas injection holes located at a radial distance of about 7.8-7.9 inches from the center of the faceplate 410, the sixty-fifth concentric row of holes has 162 gas injection holes located at a radial distance of about 7.9-8 inches from the center of the faceplate 410, the sixty-sixth concentric row of holes has 160 gas injection holes located at a radial distance of about 8.1-8.2 inches from the center of the faceplate 410, the sixty-seventh concentric row of holes has 158 gas injection holes located at a radial distance of about 8.2-8.3 inches from the center of the faceplate 410, the sixty-eighth concentric row of holes has 156 gas injection holes located at a radial distance of about 8.3-8.4 inches from the center of the faceplate 410, the sixty-ninth concentric row of holes has 154 gas injection holes located at a radial distance of about 8.4-8.5 inches from the center of the faceplate 410, the seventieth concentric row of holes has 152 gas injection holes located at a radial distance of about 8.5-8.6 inches from the center of the faceplate 410, the seventieth3-5.4 inches, a forty-second concentric row of gas injection holes having 198 gas injection holes located at a radial distance of about 5.45-5.55 inches from the center of the faceplate 410, a forty-third concentric row of gas injection holes having 160 gas injection holes located at a radial distance of about 5.6-5.7 inches from the center of the faceplate 410, a forty-fourth concentric row of gas injection holes having 160 gas injection holes located at a radial distance of about 5.7-5.8 inches from the center of the faceplate 410, and a forty-fifth concentric row of gas injection holes having 140 gas injection holes located at a radial distance of about 5.85-5.95 inches from the center of the faceplate 410. Preferably, the gas injection holes 444 of each concentric row of gas injection holes are equally spaced about the center of the faceplate 410 (i.e., the distance between adjacent gas injection holes in each concentric row of gas injection holes is approximately the same).

[0045] Referring back to Figure 1 The semiconductor substrate plasma processing apparatus 300 includes a controller 162, which can be integrated with electronics, for controlling the operations of the embodiments of the semiconductor substrate plasma processing apparatus 300 as disclosed herein and for carrying out the embodiments of the method as disclosed herein. The electronics can be referred to as the “controller” which can control various components or subparts of the system or sub-system. It will be understood that the controller can control one or more components or subparts of the system, and that the controller can control components or subparts of multiple systems or sub-systems.

[0046] Broadly speaking, the controller can be defined as electronics having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits can include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors, or microcontrollers that execute program instructions (e.g., software). Program instructions can be instructions communicated to the controller in the form of various sets of programmed instructions, or program files, which define the operations to be performed by the controller on or for a semiconductor wafer or system. In some embodiments, the operations may

[0047] In some implementations, the controller 162 can be a part of, or coupled to, a computer that is integrated with the system, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller can be in the "cloud" or a fab host computer that can allow remote access by the operator to the system or a part thereof. The computer can enable remote access to the system to monitor current progress of fabrication operations, examine a history of past fabrication operations, examine trends or performance metrics from a plurality of fabrication operations, change parameters of current processing, set processing steps to follow of the current fabrication operation, or start a new process. In some examples, a remote computer (e.g. a server) can provide process recipes to a system over a network, which can include a local network or the Internet. The remote computer can include a user interface that allows a user to input or edit parameters and / or settings, which are then transmitted over the network to the system. In some examples, the controller receives instructions in the form of data, which specify parameters for each processing step to be performed during one or more operations. It should be understood that the parameters can be specific to a type of process to be performed and a type of tool that the controller is configured to interface with or control.

[0048] As described above, depending on the process step or steps to be performed by the semiconductor substrate plasma processing apparatus 300, the controller 162 can communicate with one or more other tool circuits or modules, other tool components, combined tools, other tool interfaces, adjacent tools, contiguous tools, tools located throughout a factory, a host computer, another controller, or tools used in material transport that bring containers of wafers to and from tool locations and / or ports in a semiconductor manufacturing factory. Preferably, the non-transitory computer machine- readable medium comprises program instructions for controlling the semiconductor substrate plasma processing apparatus 300.

[0049] In one embodiment, a method of minimizing seam effects of a TEOS oxide film deposited during a trench fill process performed on a semiconductor substrate in a semiconductor substrate plasma processing apparatus includes supporting the semiconductor substrate on a pedestal in a vacuum chamber of the semiconductor substrate plasma processing apparatus, wherein the semiconductor substrate includes at least one trench on an upper surface thereof. A process gas including TEOS, an oxidizer, and argon is flowed through a faceplate of a showerhead assembly of the semiconductor substrate plasma processing apparatus into a processing region above the upper surface of the semiconductor substrate in the vacuum chamber. RF energy is supplied into the processing region of the vacuum chamber with at least one RF generator to ignite the process gas into a plasma, wherein a TEOS oxide film is deposited on the upper surface of the semiconductor substrate to fill the at least one trench thereof, wherein the argon is supplied in an amount sufficient to increase an electron density in the plasma such that a deposition rate of the TEOS oxide film toward a center of the semiconductor substrate is increased, and seam effects of the TEOS oxide film deposited in the at least one trench are reduced.

[0050] Preferably, the process gas further includes helium, wherein the helium is supplied to the vacuum chamber in a flow rate sufficient to increase an electron density in the plasma such that a deposition rate of the TEOS oxide film toward an outer periphery of the semiconductor substrate is increased, and seam effects of the TEOS oxide film deposited in the at least one trench are reduced.

[0051] In one embodiment, the RF energy is supplied to the processing region of the vacuum chamber with a high frequency RF generator powered at about 1100 to 1700 W, and with a low frequency RF generator powered at about 1550 to 2400 W, and the vacuum chamber is maintained at a pressure of about 3-5 Torr or about 4 Torr during processing, wherein the TEOS oxide film is preferably deposited to a thickness of about 1000 Angstroms to 30000 Angstroms.

[0052] The embodiments disclosed herein have been described with reference to the preferred embodiments. It will be evident, however, to agents skilled in the art, that the application can be embodied in other specific forms without departing from the spirit or essential character thereof. The preferred embodiments are to be considered in all respects as illustrative only; not as restrictive.

Claims

1. A method of minimizing seam effects of a TEOS oxide film deposited during a trench fill process performed on a semiconductor substrate in a semiconductor substrate plasma processing apparatus, the method comprising: supporting a semiconductor substrate on a pedestal in a vacuum chamber of the semiconductor substrate plasma processing apparatus, wherein the semiconductor substrate includes at least one trench in an upper surface thereof; flowing a process gas including TEOS, an oxidizer, and argon through a showerhead assembly of the semiconductor substrate plasma processing apparatus into a processing region of the vacuum chamber above the upper surface of the semiconductor substrate; supplying RF energy to the processing region of the vacuum chamber with at least one RF generator to energize the process gas into a plasma; and depositing a TEOS oxide film on the upper surface of the semiconductor substrate to fill the at least one trench therein, wherein the seam effects of the TEOS oxide film deposited in the at least one trench are reduced by controlling a flow rate of argon in a process gas mixture.

2. The method of claim 1, wherein the argon is supplied in an amount sufficient to increase an electron density of the plasma such that a deposition rate of the TEOS oxide film towards a center of the semiconductor substrate is increased.

3. The method of claim 1, wherein the argon is supplied to the vacuum chamber at a flow rate of about 2000 to 6000 seem, wherein the term "about" means ± 10%.

4. The method of claim 3, wherein the argon is supplied to the vacuum chamber at a flow rate of about 3000 to 5000 seem, wherein the term "about" means ± 10%.

5. The method of claim 3, wherein the argon is supplied to the vacuum chamber at a flow rate of about 4000 seem, wherein the term "about" means ± 10%.

6. The method of claim 1, wherein the process gas further includes helium, wherein the seam effects of the TEOS oxide film deposited in the at least one trench are reduced by controlling a flow rate of helium in the process gas mixture.

7. The method of claim 6, wherein the helium is supplied to the vacuum chamber at a flow rate sufficient to increase an electron density in the plasma such that a deposition rate of the TEOS oxide film towards a periphery of the semiconductor substrate is increased.

8. The method of claim 6, wherein the helium is supplied to the vacuum chamber at a flow rate of about 3000 to 5000 seem, wherein the term "about" means ± 10%.

9. The method of claim 8, wherein the helium is supplied to the vacuum chamber at a flow rate of about 3500-4500 seem, wherein the term "about" means ± 10%.

10. The method of claim 8, wherein the helium is supplied to the vacuum chamber at a flow rate of about 4000 seem, wherein the term "about" means ± 10%.

11. The method of claim 1 , wherein the oxidant is O 2 or ozone, and the oxidant is supplied to the vacuum chamber at a flow rate of about 15,000 sccm-23,000 sccm, wherein the term “about” refers to ±10%.

12. The method of claim 11, wherein the oxidant is O2 or ozone, and the oxidant is supplied to the vacuum chamber at a flow rate of about 18,000-20,000 sccm, wherein the term "about" refers to ±10%.

13. The method of claim 11, wherein the oxidant is O2 or ozone, and the oxidant is supplied to the vacuum chamber at a flow rate of about 19,000 sccm, wherein the term "about" refers to ±10%.

14. The method of claim 1 , wherein supplying RF energy to the processing region of the vacuum chamber using at least one RF generator comprises supplying RF energy having a frequency of approximately 2 to 60 MHz into the processing region of the vacuum chamber using a high frequency RF generator powered at approximately 1100 W to 1700 W and supplying RF energy having a frequency of approximately 50 to 800 kHz into the processing region of the vacuum chamber using a low frequency RF generator powered at approximately 1550 to 2400 W, wherein the term “approximately” refers to ±10%.

15. The method of claim 1, wherein the vacuum chamber is maintained at a pressure of about 3-5 Torr, wherein the term "about" refers to ±10%.

16. The method of claim 15, wherein the vacuum chamber is maintained at a pressure of about 4 Torr, wherein the term "about" refers to ±10%.

17. The method of claim 1 , further comprising flowing liquid TEOS at a flow rate of about 11-17 ml / min to a heated manifold operable to vaporize the liquid TEOS, wherein the heated manifold is in fluid communication with the showerhead assembly such that the vaporized TEOS flows through the showerhead assembly to the processing region above the semiconductor substrate, wherein the term “about” refers to ±10%.

18. The method of claim 17 , further comprising flowing liquid TEOS at a flow rate of about 14 ml / min to a heated manifold operable to vaporize the liquid TEOS, wherein the heated manifold is in fluid communication with the showerhead assembly such that the vaporized TEOS flows through the showerhead assembly to the processing region above the semiconductor substrate, wherein the term “about” refers to ±10%.

19. The method of claim 1, wherein, The TEOS oxide film is deposited to a thickness of about 1,000 angstroms to 30,000 angstroms, where the term "about" refers to ±10%.

20. The method of claim 8, wherein the flow rate of liquid TEOS before vaporization is about 14 ml / min, the flow rate of the helium gas is about 4,000 sccm, the flow rate of the argon gas is about 3,000 sccm, and the flow rate of the oxidant is about 19,000 sccm, wherein the term "about" refers to ±10%.

21. The method of claim 14, wherein the high frequency RF generator has a power of about 1400 W, the low frequency RF generator has a power of about 1950 W, and the pressure in the vacuum chamber is maintained at about 4 Torr, wherein the term "about" means ±10%.

22. The method of claim 1, wherein the tensile film stress of the TEOS oxide film produced is about 0 to 150 MPa, wherein the term "about" means ±10%.

23. The method of claim 1, wherein the compressive film stress of the TEOS oxide film produced is between 150-400 MPa.

24. A semiconductor substrate treated according to the method of claim 1.

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