Process stage transition detection for plasma systems

Abstract

The goal of the gap-fill deposition process may be to form a relatively flat overgrowth layer of gap-fill material on top of the pillars. This relatively flat overgrowth layer can be formed by automatically stopping the gap-fill deposition process after detecting the end of a stage of the gap-fill process (e.g., the sidewall growth stage). Plasma characteristics, such as plasma impedance, can be monitored during the plasma process. Changes in characteristics may correlate with different stages in the process, such as different stages in the gap-fill process. When characteristics appear, the stage in the gap-fill process can be identified, and measures such as stopping the gap-fill process can be taken. This provides live monitoring of the gap-fill based on plasma characteristics rather than based on measurements taken after the gap-fill process is completed.

Description

Technology Field

[0001] This application claims the benefit and priority of U.S. Regular Application No. 18 / 420,376, filed January 23, 2024, under the title “PROCESS STAGE TRANSITION DETECTION FOR PLASMA SYSTEMS”, the contents of which are incorporated herein by reference in their entirety for all purposes.

[0002] The present disclosure generally describes plasma system fabrication processes. More specifically, the present disclosure describes in-situ stage transition detection for plasma system fabrication processes. Background Technology

[0003] Integrated circuits are made possible by processes that create complexly patterned material layers on substrate surfaces. Creating patterned materials on a substrate requires controlled methods for the formation and removal of exposed materials. As device sizes continue to shrink, material formation can affect subsequent operations. For example, in gap filling operations, material may be formed or deposited to fill trenches or other features formed on a semiconductor substrate. Gap filling operations may involve multiple stages during the gap fill deposition process. For some devices, it may be necessary to detect transitions from one stage to another in order to effectively fabricate high-quality devices and structures.

[0004] Therefore, there is a need for improved systems and methods that can be used to produce high-quality devices and structures. These and other needs are addressed by the present technology.

[0005] In some embodiments, the method may include: measuring a characteristic of the plasma; monitoring a characteristic of the plasma during a process involving the plasma; detecting the end of a stage of the process based on a comparison of the measured characteristic and a reference value; and performing at least one action in response to detecting the end of a stage of the process.

[0006] In some embodiments, the system may include: a plasma system configured to perform deposition processes or etching processes; at least one sensor configured to measure the characteristics of the plasma within the plasma system; and a controller, wherein the controller has one or more processors and one or more memory devices, and the one or more memory devices include instructions executable by the processors to enable the processors to perform operations including monitoring the characteristics during a process involving plasma. The operations may also include an operation to detect the end of a stage of the process based on a comparison of the characteristics and a reference value; and an operation to perform at least one action in response to the detection of the end of a stage of the process.

[0007] In some embodiments, one or more non-transient computer-readable media may include instructions that, when executed by one or more processors, cause one or more processors to perform operations including: monitoring a measured characteristic of plasma during a process involving plasma; detecting the end of a stage of the process based on a comparison of the measured characteristic and a reference value; and performing at least one action in response to detecting the end of a stage of the process.

[0008] In any embodiment, any and / or all of the following features may be implemented in any combination and without limitation. The feature may include the impedance of the plasma, the process is a plasma-enhanced chemical vapor deposition (PECVD) gap-fill deposition process for a patterned sample, the stage of the process may include a sidewall pinch-off stage, and performing at least one action may include automatically terminating the process after a duration of time measured from detection. The patterned sample may include a plurality of trenches, and at least one of the plurality of trenches may have dimensions different from the dimensions of any other trench among the plurality of trenches. The gap-fill deposition process may include the deposition of a gap-fill material comprising carbon, tungsten, or amorphous silicon. Reference values ​​may be based on conditions associated with the process. Conditions associated with the process may include types of plasma gases, a flow rate of at least one plasma gas, a temperature, precursors associated with the process, at least one deposition rate, or at least one etching rate. A slope of a characteristic over time for a part of the process may be measured, and at least one step in the sample patterning process may be changed based on the slope. Brief explanation of the drawing

[0009] Further understanding of the properties and advantages of the various embodiments can be achieved by referring to the drawings and the remainder of this specification, wherein similar reference numbers are used throughout the drawings to refer to similar components. In some cases, a sub-label is associated with a reference number to denote one of a number of similar components. When a reference number is referred to without specifying an existing sub-label, it is intended to refer to all such a number of similar components.

[0010] FIG. 1 illustrates a schematic cross-sectional view of an exemplary processing chamber according to some embodiments of the present technology.

[0011] FIG. 2 illustrates a schematic cross-sectional view of a patterned sample that can be incorporated into processes according to some embodiments.

[0012] FIG. 3 illustrates schematic cross-sectional views of patterned samples during different parts of a gap-fill deposition process according to some embodiments.

[0013] FIG. 4 is a graph of the characteristics of the plasma during the gap-fill deposition process according to some embodiments.

[0014] FIG. 5 is a cross-sectional transmission electron microscope (TEM) image of a patterned sample having trenches partially filled with gap-fill material according to some embodiments.

[0015] FIG. 6 is a flowchart of an example of a process for detecting the end of a stage of a deposition process according to some aspects of the present disclosure.

[0016] FIG. 7 illustrates an exemplary computer system in which various embodiments can be implemented. Specific details for implementing the invention

[0017] Specific aspects and examples of the present disclosure relate to stage transition detection for a fabrication process involving a plasma system. For example, the fabrication process may be a gap-fill deposition process of a patterned sample comprising pillars and trenches. The pillars and trenches may include dimensions of various sizes, which may present challenges in optimizing aspects of the deposition process. The goal of the gap-fill deposition process may be to form a relatively flat overgrowth layer of gap-fill material on top of the pillars. The relatively flat overgrowth layer may be formed by automatically stopping the gap-fill deposition process after a duration has elapsed following the detection of the end of a stage of the fabrication process (e.g., a sidewall growth stage). Plasma properties, such as plasma impedance, may be monitored during the plasma process. Changes in properties may be correlated with different stages in the process, such as different stages in the gap-fill process. When characteristics appear, the stage in the gap fill process can be identified, and measures such as stopping the gap fill process can be taken. This provides in situ monitoring of the gap fill based on plasma characteristics, rather than measurements taken after the gap fill process is completed or intrusive measurements.

[0018] After describing general aspects of chambers according to some embodiments of the present technology in which the plasma processing operations discussed below can be performed, specific methodologies may be discussed. It should be understood that the present technology is not intended to be limited to the specific films, chambers, or processes discussed, as the described techniques can be used to improve a number of film formation processes and may be applicable to various processing chambers and operations.

[0019] FIG. 1 illustrates a cross-sectional view of an exemplary processing chamber (100) according to some embodiments of the present invention. The drawing may illustrate an overview of a system that may be specifically configured to incorporate one or more aspects of the present invention and / or perform one or more operations according to embodiments of the present invention. Further details of the chamber (100) or the methods performed may be further described below. The chamber (100) may be utilized to form film layers, etch material layers, form other material layers, or perform a combination thereof, but it should be understood that deposition and etching methods may similarly be performed within any chamber where deposition and etching processes may occur internally. The processing chamber (100) may include a chamber body (102), a substrate support (104) disposed within the chamber body (102), and a cover assembly (106) coupled to the chamber body (102) and enclosing the substrate support (104) within a processing volume (120). The substrate (103) may be provided to the processing volume (120) through an opening (126) that can be typically sealed for processing using a slit valve or door. The substrate (103) may be placed on the surface (105) of the substrate support during processing. In some embodiments, the substrate support (104) may be rotatable along a vertical axis where the shaft (144) of the substrate support (104) may be positioned, or it may be fixed. Alternatively, the substrate support (104) may be lifted to rotate as needed during the deposition process.

[0020] The gas distributor (112) may define apertures (118) for distributing process precursors into a processing volume (120). The gas distributor (112) may be coupled to a first electric power source (142), such as an RF generator, an RF power source, a DC power source, a pulsed DC power source, a pulsed RF power source, or any other power source that can be coupled to the processing chamber. In some embodiments, the first electric power source (142) may be an RF power source.

[0021] The gas distributor (112) may be a conductive gas distributor or a non-conductive gas distributor. The gas distributor (112) may also be formed of conductive and non-conductive components. For example, the body of the gas distributor (112) may be conductive, while the face plate of the gas distributor (112) may be non-conductive. The gas distributor (112) may be powered by a first electric power source (142), for example, as shown in FIG. 1, or the gas distributor (112) may be coupled to ground in some embodiments.

[0022] The first electrode (122) may be coupled to the substrate support (104). The first electrode (122) may be embedded within the substrate support (104) or coupled to the surface of the substrate support (104). The first electrode (122) may be a plate, a perforated plate, a mesh, a wire screen, or any other distributed arrangement of conductive elements. The first electrode (122) may be a tuning electrode and may be coupled to a tuning circuit (136) by a cable having a selected resistance, such as 50 ohms, placed within the shaft (144) of the substrate support (104), for example, by a conduit (146). The tuning circuit (136) may have an electronic sensor (138) and an electronic controller (140), and the electronic controller (140) may be a variable capacitor. The electronic sensor (138) may be a voltage or current sensor and may be coupled with an electronic controller (140) to provide additional control over plasma conditions within the processing volume (120).

[0023] A second electrode (124), which may be a bias electrode and / or an electrostatic chucking electrode, may be coupled to a substrate support (104). The second electrode may be coupled to a second electric power source (150) through a filter (148), which may be an impedance matching circuit. The second electric power source (150) may be DC power, pulsed DC power, RF bias power, pulsed RF source or bias power, or a combination of these or other power sources. In some embodiments, the second electric power source (150) may be RF bias power. The substrate support (104) may also include one or more heating elements configured to heat the substrate to a processing temperature, the processing temperature may be about 25°C to about 800°C or higher.

[0024] The cover assembly (106) and substrate support (104) of FIG. 1 may be used in any processing chamber for plasma or thermal processing. In operation, the processing chamber (100) may provide real-time control of plasma conditions within the processing volume (120) through a system controller (101) that may be included, for example, in a processor (107). A substrate (103) may be placed on the substrate support (104), and process gases may flow through the cover assembly (106) using an inlet (114) according to any desired flow plan. The gases may exit the processing chamber (100) through an outlet (152). Electric power may be coupled with a gas distributor (112) to establish plasma within the processing volume (120). In some embodiments, the substrate may be electrically biased using a second electrode (124).

[0025] When energizing the plasma within the processing volume (120), a potential difference can be established between the plasma and the first electrode (122). Then, the electronic controller (140) can be used to control the flow properties of the ground paths represented by the tuning circuit (136). A set point can be transmitted to the tuning circuit (136) to provide independent control of plasma density uniformity and deposition rate from the center to the edge. In embodiments where both electronic controllers may be variable capacitors, the electronic sensors can independently control the variable capacitors to maximize the deposition rate and minimize thickness non-uniformity.

[0026] The tuning circuit (136) may have a variable impedance that can be adjusted using an electronic controller (140). If the electronic controller (140) is a variable capacitor, the capacitance range of each variable capacitor may be selected to provide an impedance range. This range may vary depending on the frequency and voltage characteristics of the plasma, which may have a minimum value at the capacitance range of each variable capacitor. Thus, when the capacitance of the electronic controller (140) is at a minimum or maximum value, the impedance of the tuning circuit (136) may be high, which may result in a plasma shape having minimal aerial or lateral coverage over the substrate support. When the capacitance of the electronic controller (140) approaches a value that minimizes the impedance of the tuning circuit (136), the aerial coverage of the plasma may increase to a maximum value, which can effectively cover the entire working area of ​​the substrate support (104). When the capacitance of the electronic controller (140) deviates from the minimum impedance setting, the plasma shape may shrink from the chamber walls and the aerial coverage of the substrate support may be reduced.

[0027] The electronic sensor (138) can be used to tune the tuning circuit (136) in a closed-loop manner. Depending on the type of sensor used, a set point for current or voltage may be installed on each sensor, and the sensor may be provided with control software that determines the adjustment to the electronic controller (140) to minimize deviation from the set point. Consequently, the plasma shape can be selected and dynamically controlled during processing. Although the foregoing discussion is based on the electronic controller (140), which may be a variable capacitor, it should be understood that any electronic component having adjustable characteristics may be used to provide adjustable impedance to the tuning circuit (136).

[0028] The processing chamber (100) may be utilized in some embodiments of the present technology for processing methods that may include bottom-up deposition of materials for semiconductor structures. It should be understood that the chamber described is not to be considered limiting, and any chamber configured to perform operations as described may be similarly used.

[0029] FIG. 2 illustrates a schematic cross-sectional view of a patterned sample (200) that may be incorporated into processes according to some embodiments. The patterned sample (200) may include a substrate (206) and pillars, such as pillar (202A), pillar (202B), and pillar (202C). Although three pillars are shown in FIG. 2, the patterned sample (200) may include any number of pillars. Each of the pillars may be formed from a plurality of alternating deposited layers, such as layer (203) or layer (204). Layer (203) and layer (204) may be deposited layers of a memory stack structure, such as a NAND structure. For example, layer (203) may be a deposited silicon oxide layer, and layer (204) may be a deposited silicon nitride layer. Although multiple alternating deposition layers are illustrated in FIG. 2, only layers (203) and (204) are labeled for simplification. The alternating deposition layers may have layer thicknesses. For example, layer (203) may have a thickness t1, and layer (204) may have a thickness t2. In some examples, each of the alternating layers may have the same thickness (t1=t2).

[0030] For example, each of the alternating layers can have a thickness of about 50 nm. For example, each alternating layer may have a thickness of about 5 nm to about 10 nm, about 10 nm to about 15 nm, about 15 nm to about 20 nm, about 20 nm to about 25 nm, about 25 nm to about 30 nm, about 30 nm to about 35 nm, about 35 nm to about 40 nm, about 40 nm to about 45 nm, about 45 nm to about 50 nm, about 50 nm to about 55 nm, about 55 nm to about 60 nm, about 60 nm to about 65 nm, about 65 nm to about 70 nm, about 70 nm to about 75 nm, about 75 nm to about 80 nm, about 80 nm to about 85 nm, about 85 nm to about 90 nm, about 90 nm to about 95 nm, and / or about 95 nm to about 100 nm. The thickness of each layer may also be any combination of these ranges (e.g., about 50 nm to about 100 nm). The thickness of each layer may also be any specific value within these ranges (e.g., about 50 nm). Each alternating layer may have a different thickness. For example, the thickness of layer (203) may be different from the thickness of layer (204) (t1 ≠ t2).

[0031] Multiple alternating deposited layers can be etched to form pillars. Etched zones between adjacent pillars can form trenches. Each trench can have a width w and a height h. The trenches can be relatively deep trenches (e.g., h >> w). For example, the width of a trench can be about 100 nm. For example, each trench may have a width of about 10 nm to about 30 nm, about 30 nm to about 50 nm, about 50 nm to about 70 nm, about 70 nm to about 90 nm, about 90 nm to about 110 nm, about 110 nm to about 130 nm, about 130 nm to about 150 nm, about 150 nm to about 170 nm, about 170 nm to about 190 nm, about 190 nm to about 210 nm, about 210 nm to about 230 nm, about 230 nm to about 250 nm, about 250 nm to about 270 nm, about 270 nm to about 290 nm, about 290 nm to about 310 nm, about 310 nm to about 330 nm, and / or about 330 nm to about 350 nm. The width of each trench may also be any combination of these ranges (e.g., about 10 nm to about 350 nm). The width of each trench may also be any specific value within these ranges (e.g., about 150 nm).

[0032] The height of the trench can be about 10 microns. For example, each trench may have a height of about 1 micron to about 3 microns, about 3 microns to about 5 microns, about 5 microns to about 7 microns, about 7 microns to about 9 microns, about 9 microns to about 11 microns, about 11 microns to about 13 microns, about 13 microns to about 15 microns, about 15 microns to about 17 microns, about 17 microns to about 19 microns, about 19 microns to about 21 microns, about 21 microns to about 23 microns, about 23 microns to about 25 microns, about 25 microns to about 27 microns, about 27 microns to about 29 microns, about 29 microns to about 31 microns, about 31 microns to about 33 microns, and / or about 33 microns to about 35 microns. The height of each trench may also be any combination of these ranges (e.g., about 30 microns to about 35 microns). The height of each trench may also be any specific value within these ranges (e.g., about 150 microns). In some examples, the height of each trench may be designed to be a multiplicative factor of the width of each trench (e.g., h = 50*w, h = 100*w, etc.).

[0033] Height h, width w, or both may have different values ​​in different regions of the patterned sample (200). For example, the patterned sample (200) may be divided into four quadrants. In the first quadrant, a first subgroup of pillars may have widths of 10 nm and heights of 5 microns. In the second quadrant, a second subgroup of pillars may have widths of 50 nm and heights of 25 microns. The third quadrant may include a third subgroup of pillars having widths of 20 nm and heights of 10 microns. In the fourth quadrant, a fourth subgroup of pillars may have widths of 24 nm and heights of 10 microns.

[0034] The patterned sample (200) can be incorporated into a process such as a deposition process. For example, the patterned sample (200) can be placed in a process chamber such as the process chamber (100) of FIG. 1, and the trenches of the patterned sample (200) can be filled with a plugfill material during a plasma-enhanced chemical vapor deposition (PECVD) process. During the PECVD process, the start and end of the stages of the PECVD process can be detected by monitoring changes in the characteristics of the plasma (e.g., impedance, etc.) over time.

[0035] FIG. 3 illustrates schematic diagrams of multiple cross-sectional views of a patterned sample during different parts of a gap-fill deposition process according to some embodiments. The patterned sample may be the patterned sample (200) from FIG. 2. The first cross-sectional view (302) illustrates the patterned sample during an initial stage of the gap-fill process. The patterned sample may include multiple pillars, such as pillar (202A), pillar (202B), or pillar (202C). Trenchs may be formed on the patterned sample within the spaces between the pillars. For example, trenches may be formed between pillar (202A) and pillar (202B) or between pillar (202B) and pillar (202C). The gap-fill deposition process may involve filling the trenches with a gap-fill material (315). Examples of gap-fill materials (315) may include carbon, tungsten, amorphous silicon, etc. The patterned sample may be placed in a process chamber (e.g., the process chamber (100) of FIG. 1), and the gap-fill deposition process may be a PECVD deposition process.

[0036] During the initial stage of the gap-fill process, the gap-fill material (315) may accumulate within the trenches and on the tops of the pillars. The gap-fill material (315) formed on the pillars may be referred to as overgrowth. The deposition of the gap-fill material (315) within the trenches may be described as sidewall growth or sidewall deposition. For example, in the first cross-sectional view (302), most of the gap-fill material (315) shown in the trench between pillar (202A) and pillar (202B) is accumulated on the sides of the trench. A portion of the gap-fill material (315) is formed on the right side of pillar (202A) and is growing toward the left side of pillar (202B). Additionally, a portion of the gap-fill material (315) within the trench is formed on the left side of pillar (202B) and is growing toward the right side of pillar (202A). The initial stage of the gap-fill deposition process can be described as a sidewall formation or sidewall growth stage.

[0037] The second cross-sectional view (304) illustrates a patterned sample during the transition from the initial stage of the gap-fill deposition process to the second stage of the gap-fill deposition process. The second stage of the gap-fill deposition process may be described as a pinch-off stage. The second cross-sectional view (304) may represent the onset of the pinch-off stage. Pinch-off may occur when sidewall growth on one side of a trench comes into contact with sidewall growth on the other side of the trench (e.g., the opposite side). The onset of the second stage may occur when at least one trench experiences pinch-off. Due to non-uniformity of the patterned sample or due to different dimensions of the trenches, the trenches of the patterned sample may experience pinch-off at different times during the gap-fill deposition process.

[0038] A third cross-sectional view (306) illustrates a patterned sample during the second stage or pinch-off stage of the gap-fill deposition process. During the pinch-off stage, the number of trenches experiencing pinch-off accumulates. During this second stage, some trenches that experience pinch-off early may accumulate additional overgrowth. A fourth cross-sectional view (308) illustrates a patterned sample during the transition from the second stage to the third stage of the gap-fill deposition process. The initiation of the third stage may occur once every individual (or nearly every individual) trench has experienced pinch-off. The third stage may be a stage where all trenches experience an accumulation of overgrowth. A fourth cross-sectional view (310) depicts a patterned sample during the third stage of the gap-fill deposition process.

[0039] FIG. 4 is a graph (400) of the time-dependent characteristics of the plasma during a gap-fill deposition process according to some embodiments. The graph (400) may include two plots, and the first plot (402) represents the characteristics of the plasma while filling the trenches within the patterned sample with a gap fill. For example, the characteristics of the plasma may be the impedance value of the plasma. The graph may also include a second plot (404) representing a constant reference value of the characteristics of the plasma. The constant reference value may be associated with the characteristics of the plasma while the unpatterned sample is present. The characteristics represented by the second plot (404) may be based on the conditions present during the gap-fill deposition process for the patterned sample.

[0040] The first plot (402) may represent the time dependence of various stages of the gap-fill deposition process. The first transition time (406) may represent the time when the slope of the first plot (402) changes abruptly from a value of nearly zero to a value of nearly constant negative. The first transition time (406) may represent the transition from the first stage (410) of the gap-fill process to the second stage (412) of the gap-fill process. The first stage (410) may be associated with sidewall growth and may be evident in the first plot by the first time period prior to the first transition time. The second stage (412) of the gap-fill process may be referred to as the pinch-off stage of the gap-fill process. The second stage (412) may be associated with a region of the graph (400) where the first plot (402) experiences a nearly constant negative slope, the number of trenches of the patterned sample experiencing pinch-off accumulates, and the characteristics of the plasma approach a reference value of the second plot (404). The magnitude of the nearly constant negative slope may indicate the degree of uniformity of the patterned sample. The more uniform the patterned sample, the steeper the constant negative slope may be. More uniformity may mean less variation in the width of the trenches, the height of the trenches, or a combination of both of these dimensions. The endpoint for the second stage (412) may occur when all (or nearly all) of the trenches experience pinch-off.

[0041] The second transition time (408) may indicate the time when the slope of the first plot (402) changes abruptly from a nearly constant negative value to nearly zero. At the second transition time, the first plot (402) is aligned with the second plot (404), and the plasma characteristics match the reference value. The second transition time (408) may indicate the end of the pinch-off stage of the gap-fill deposition process. The second transition time (408) may be detected by comparing the measured characteristic value (the value of the first plot (402)) with the reference value from the second plot (404). If the comparison indicates that the two values ​​match (within a predetermined safety factor), the end of the pinch-off phase may be detected. Once the pinch-off phase ends, a third phase of overgrowth accumulation for all trenches may begin. After a predetermined time following the occurrence of the second transition time, the process may be automatically terminated.

[0042] FIG. 5 is a cross-sectional transmission electron microscope (TEM) image (500) of a patterned sample having trenches partially filled with a gap-fill material (515) according to some embodiments. The TEM image (500) illustrates a snapshot of multiple pillars including a pillar (502) during the sidewall growth stage of the gap-fill deposition process. Although multiple pillars are shown in FIG. 5, only the pillar (502) is labeled for simplification. The sidewall growth stage may be clear in the TEM image (500) due to the lack of pinch-off. The sidewalls of each pillar appear not to touch the sidewalls of any other pillars in the TEM image (500).

[0043] The TEM image (500) also includes a boundary line (520). The boundary line (520) indicates the uppermost boundary of each of the pillars. Any gap-fill material (515) accumulated on the boundary line (520) can be considered as overburden. In the example illustrated in FIG. 5, the widths of the pillars are about 50 nm, the visible portion of the heights of the pillars is about 700 nm, the overburden height is about 100 nm, and the trench widths are about 130 nm. In FIG. 5, sidewall growth appears to vary slightly per pillar and with depth, having a range of about 20 to 40 nm.

[0044] FIG. 6 is a flowchart of an example of a process (600) for detecting the end of a stage of a deposition process according to some aspects of the present disclosure. The operations of the flowchart begin at block (610) and may be performed in the order shown or in any suitable order. Other examples may involve more, fewer, different, or different orders of operations than those shown in FIG. 6. Some or all of the steps of the process (600) may be performed by processors. For exemplary purposes, the process (600) is described with respect to a deposition process, but the description of the process (600) included in the present disclosure is applicable to methods and systems for etching processes as well. It can make it possible to apply.

[0045] In block (610), the process (600) involves a step of measuring the characteristics of the plasma. The plasma may be formed within a processing chamber such as the processing chamber (100) described above. The characteristics of the plasma may be the impedance of the plasma. The impedance may be a radio-frequency (RF) impedance that can be measured by at least one sensor within the processing chamber. At least one sensor may include a matching circuit for determining the impedance of the plasma.

[0046] In block (620), the process (600) involves a step of monitoring the impedance of the plasma during the deposition process for the patterned sample. The deposition process may be a backfill deposition process involving depositing backfill material within trenches on the patterned sample. The trenches of the patterned sample may have different dimensions. For example, a first zone of the patterned sample may include pillars having a width of 100 nm, and a second zone of the patterned sample may include pillars having a width of 200 nm. The backfill material may include carbon, tungsten, amorphous silicon, etc. The step of monitoring the impedance may include a step of generating a graph of plasma impedance versus time. The plot on the impedance versus time graph may behave similarly to the plot (402) on the graph (400) of FIG. 4. The plot may include zones of a constant slope that may be associated with the stages of the backfill deposition process. For example, a portion of the graph with a constant negative slope may be associated with the sidewall pinch-off stage of the back-fill deposition process. The magnitude of the negative slope may be a measure of the uniformity of the patterned sample. In some examples, the magnitude of the negative slope may be measured, and the sample patterning process may be modified based on the measured slope value.

[0047] In block (630), the process (600) includes a step of detecting the end of a stage of the deposition process based on conditions such as a measured impedance. The stage may be a sidewall pinch-off stage. The end of the sidewall pinch-off stage may be detected when the measured impedance of the plasma matches a reference value or reaches a slope change or threshold. The reference value may be an impedance value associated with an unpatterned sample. For example, if the patterned sample has a silicon substrate, the reference value may be determined using bare, unpatterned silicon. The reference value may be based on conditions associated with the deposition process. Conditions associated with the deposition process may include types of plasma gases, a flow rate of at least one of the gases, a co-flow rate of the plasma gas and the deposition precursor, temperature, precursors associated with the deposition process, at least one deposition rate, or at least one etching rate. In some examples, the termination of the sidewall pinch-off stage can be detected based on a change in the slope of a monitored graph of plasma impedance versus time.

[0048] In block (640), the process (600) comprises a step of performing an action, such as automatically terminating the deposition process after a duration measured from the detection of the end of a stage of the deposition process. The action may be performed in response to the detection of the end of a stage of the deposition process. The stage may be a sidewall pinch-off stage. The duration may be a predetermined amount of time and may be based on a deposition rate for backfill material or a target height for an overgrowth layer. The overgrowth layer may be a layer of backfill material accumulated on top of the pillars of a patterned sample. The duration may be an amount of time elapsed until a smooth overgrowth layer is formed.

[0049] FIG. 7 illustrates an exemplary computer system (700) in which various embodiments may be implemented. The system (700) may be used to implement any of the computer systems described above. As illustrated in the drawing, the computer system (700) includes a processing unit (704) that communicates with a number of peripheral subsystems via a bus subsystem (702). These peripheral subsystems may include a processing acceleration unit (706), an I / O subsystem (708), a storage subsystem (718), and a communication subsystem (724). The storage subsystem (718) includes tangible computer-readable storage media (722) and system memory (710).

[0050] The bus subsystem (702) provides a mechanism to enable various components and subsystems of the computer system (700) to communicate with each other as intended. Although the bus subsystem (702) is schematically illustrated as a single bus, alternative embodiments of the bus subsystem may utilize multiple buses. The bus subsystem (702) may be any bus structure among various types of bus structures, including a memory bus or memory controller, a peripheral bus, and a local bus using any of the various bus architectures. For example, these architectures may include an Industry Standard Architecture (ISA) bus, a Micro Channel Architecture (MCA) bus, an Enhanced ISA (EISA) bus, a Video Electronics Standards Association (VESA) local bus, an EtherCAT bus, and a Peripheral Component Interconnect (PCI) bus, and the PCI bus may be implemented as a mezzanine bus manufactured according to the IEEE P1386.1 standard.

[0051] A processing unit (704), which may be implemented as one or more integrated circuits (e.g., a conventional microprocessor or a microcontroller), controls the operation of a computer system (700). One or more processors may be included in the processing unit (704). These processors may include single-core or multi-core processors. In certain embodiments, the processing unit (704) may be implemented as one or more independent processing units (732 and / or 734) having single or multi-core processors included in each processing unit. In other embodiments, the processing unit (704) may also be implemented as a quad-core processing unit formed by integrating two dual-core processors into a single chip.

[0052] In various embodiments, the processing unit (704) may execute various programs in response to program code and may maintain a number of concurrently executed programs or processes. At any given time, part or all of the program code to be executed may reside within the processor(s) (704) and / or within the storage subsystem (718). Through suitable programming, the processor(s) (704) may provide the various functionalities described above. The computer system (700) may additionally include a processing acceleration unit (706), which may include a digital signal processor (DSP), a special purpose processor, and / or similar.

[0053] The I / O subsystem (708) may include user interface input devices and user interface output devices. User interface input devices may include pointing devices such as keyboards, mice, or trackballs, a touchpad or touchscreen integrated into a display, audio input devices having a scroll wheel, a click wheel, a dial, a button, a switch, a keypad, a voice command recognition system, microphones, and other types of input devices.

[0054] User interface input devices may also, without limitation, include three-dimensional (3D) mice, joysticks or pointing sticks, graphic tablets, and auditory / visual devices, such as speakers, digital cameras, digital camcorders, webcams, image scanners, fingerprint scanners, barcode reader 3D scanners, and / or laser rangefinders. User interface output devices may include display subsystems, indicator lights, or non-visual displays, such as audio output devices. The display subsystem may be a flat-panel device, projection device, touch screen, and similar, such as using a cathode ray tube (CRT), liquid crystal display (LCD), or plasma display. Generally, the use of the term "output device" is intended to include all possible types of devices and mechanisms for outputting information from the computer system (700) to a user or another computer. For example, user interface output devices may include, without limitation, various display devices that visually convey text, graphics, and audio / video information, such as monitors, printers, speakers, headphones, automotive navigation systems, plotters, voice output devices, and modems.

[0055] The computer system (700) may include a storage subsystem (718) comprising software elements described as currently located within the system memory (710). The system memory (710) may store program instructions that are loadable and executable on the processing unit (704), as well as data generated during the execution of these programs.

[0056] Depending on the configuration and type of the computer system (700), the system memory (710) may be volatile (e.g., random access memory (RAM)) and / or non-volatile (e.g., read-only memory (ROM), flash memory, etc.). RAM typically contains program modules and / or data that are immediately accessible to the processing unit (704) and / or are currently being operated and executed by the processing unit (704). In some implementations, the system memory (710) may contain a number of different types of memory, such as static random access memory (SRAM) or dynamic random access memory (DRAM). In some implementations, a basic input / output system (BIOS) containing basic routines that help transfer information between elements within the computer system (700) during startup may typically be stored in ROM. For example, and without limitation, system memory (710) also exemplifies application programs (712), program data (714), and operating systems (716), which may include client applications, web browsers, mid-tier applications, relational database management systems (RDBMS), etc. For example, the operating system (716) may include mobile operating systems for use on mobile devices.

[0057] The storage subsystem (718) may also provide a computer-readable storage medium of a type for storing basic programming and data structures that provide functionality in some embodiments. Software (programs, code modules, instructions) that provide the functionality described above when executed by a processor may be stored within the storage subsystem (718). These software modules or instructions may be executed by the processing unit (704). The storage subsystem (718) may also provide a storage for storing data used according to some embodiments.

[0058] The storage subsystem (718) may also include a computer-readable storage medium reader (720) that may be additionally connected to computer-readable storage media (722). Together, and optionally in combination with system memory (710), computer-readable storage media (722) may comprehensively represent remote, local, fixed and / or removable storage devices, along with storage media for temporarily and / or more permanently containing, storing, transmitting, and retrieving computer-readable information.

[0059] Computer-readable storage media (722) comprising code or parts of code may also include any suitable media comprising storage media and communication media, such as volatile and non-volatile, removable and non-removable media (but not limited thereto) implemented by any method or technique for storing and / or transmitting information. This may include tangible computer-readable storage media, such as RAM, ROM, electronically erasable programmable ROM (EEPROM), flash memory or other memory technology, CD-ROM, digital versatile disk (DVD), or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or other types of computer-readable media. This may also include non-tangible computer-readable media, such as any other media that can be used to transmit data signals, data transmissions, or desired information and can be accessed by the computing system (700).

[0060] For example, computer-readable storage media (722) may include a hard disk drive that reads from or writes to non-removable non-volatile magnetic media, a magnetic disk drive that reads from or writes to a removable non-volatile magnetic disk, and an optical disk drive that reads from or writes to a removable non-volatile optical disk, such as a CD-ROM, DVD, and Blu-Ray® disk, or other optical media. Computer-readable storage media (722) may include (but are not limited to) flash memory cards, universal serial bus (USB) flash drives, secure digital (SD) cards, DVD disks, digital video tapes, and similar items. Computer-readable storage media (722) may also include SSDs based on non-volatile memory such as flash-memory-based solid-state drives (SSDs), enterprise flash drives, solid-state ROM, and similar ones, SSDs based on volatile memory such as solid-state RAM, dynamic RAM, static RAM, DRAM-based SSDs, magnetoresistive RAM (MRAM) SSDs, and hybrid SSDs using a combination of DRAM and flash memory-based SSDs. Disk drives and their associated computer-readable media may provide non-volatile storage of computer-readable instructions, data structures, program modules, and other data for a computer system (700).

[0061] The communication subsystem (724) provides an interface to other computer systems and networks. The communication subsystem (724) functions as an interface for receiving data from other systems and transmitting data from the computer system (700) to other systems. For example, the communication subsystem (724) can enable the computer system (700) to be connected to one or more devices via the Internet. In some embodiments, the communication subsystem (724) may include radio frequency (RF) transceiver components for accessing wireless voice and / or data networks (e.g., using cellular phone technology, advanced data network technology such as 3G, 4G or EDGE (enhanced data rates for global evolution), WiFi (IEEE 802.11 standard family), or other mobile communication technologies, or any combination thereof), global positioning system (GPS) receiver components, and / or other components. In some embodiments, the communication subsystem (724) may provide wired network connectivity (e.g., Ethernet) instead of or in addition to the wireless interface.

[0062] Additionally, the communication subsystem (724) may also be configured to receive data in the form of continuous data streams that may include event streams (728) of real-time events and / or event updates (730), and such data streams may be continuous or boundless in nature without explicit termination. Examples of applications that generate continuous data may include, for example, sensor data applications, financial tickers, network performance measurement tools (e.g., network monitoring and traffic management applications), clickstream analysis tools, automotive traffic monitoring, and similar ones.

[0063] The communication subsystem (724) may also be configured to output structured and / or unstructured data feeds (726), event streams (728), event updates (730), and similar items to one or more databases that may be communicating with one or more streaming data source computers coupled to the computer system (700).

[0064] The computer system (700) may be one of various types including a handheld portable device (e.g., smartphone, computing tablet, etc.), a PC, a workstation, a mainframe, a controller, a server rack, or any other data processing system.

[0065] Due to the ever-changing nature of computers and networks, the description of the computer system (700) depicted in the drawings is intended only as a specific example. Many other configurations are possible with more or fewer components than the system depicted in the drawings. For example, custom hardware may also be used and / or specific elements may be implemented in hardware, firmware, software (including applets), or a combination thereof. Additionally, connections to other computing devices, such as network input / output devices, may be employed. Based on the disclosures and teachings provided herein, other methods and / or manners for implementing various embodiments will be apparent.

[0066] As used herein, terms such as “about,” “approximately,” or “substantially” may be interpreted as being within the scope expected by a person skilled in the art in light of the specification.

[0067] In the foregoing description, many specific details have been presented for the purposes of explanation to provide a thorough understanding of the various embodiments. However, it will be apparent that some embodiments may be practiced without some of these specific details. In other cases, well-known structures and devices are illustrated in the form of block diagrams.

[0068] The foregoing description provides only exemplary embodiments and is not intended to limit the scope, applicability, or configuration of the disclosure. Rather, the foregoing description of various embodiments will provide an enabling disclosure for implementing at least one embodiment. It should be understood that various changes in the function and arrangement of elements may be made without departing from the spirit and scope of some embodiments as set forth in the appended claims.

[0069] Specific details are provided in the foregoing description to provide a thorough understanding of the embodiments. However, it will be understood that the embodiments may be practiced without these specific details. For example, circuits, systems, networks, processes, and other components may be illustrated as components in the form of block diagrams to avoid obscuring the embodiments with unnecessary details. In other cases, well-known circuits, processes, algorithms, structures, and techniques may be illustrated without unnecessary details to avoid obscuring the embodiments.

[0070] Additionally, it is noted that individual embodiments may be described as processes depicted as flowcharts, flow diagrams, data flow diagrams, structure diagrams, or block diagrams. While flowcharts may describe operations as sequential processes, many of the operations may be performed in parallel or simultaneously. Furthermore, the order of operations may be rearranged. A process terminates when its operations are completed, but it may have additional steps not included in the drawings. A process may correspond to a method, function, procedure, subroutine, subprogram, etc. If a process corresponds to a function, its termination may correspond to a return to the calling function or the main function.

[0071] The term “computer-readable medium” includes (but is not limited to) portable or stationary storage devices, optical storage devices, wireless channels, and various other media capable of storing, containing, or transporting instruction(s) and / or data. Code segments or machine-executable instructions may represent any combination of procedures, functions, subprograms, programs, routines, subroutines, modules, software packages, classes, or instructions, data structures, or program statements. A code segment may be coupled to another code segment or hardware circuit by transmitting and / or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be transmitted, forwarded, or sent via any suitable means, including memory sharing, message passing, token passing, network transmission, etc.

[0072] Furthermore, embodiments may be implemented by hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof. When implemented by software, firmware, middleware, or microcode, program code or code segments for performing necessary tasks may be stored on a machine-readable medium. Processor(s) may perform the necessary tasks.

[0073] In the foregoing specification, features are described with reference to specific embodiments thereof, but it should be recognized that not all embodiments are limited thereto. Various features and aspects of some embodiments may be used individually or together. Additionally, embodiments may be utilized in any number of environments and applications beyond those described herein without departing from the broader spirit and scope of the specification. Accordingly, the specification and drawings should be regarded as illustrative rather than restrictive.

[0074] Additionally, for the purposes of illustration, the methods have been described in a specific order. It should be recognized that in alternative embodiments, the methods may be performed in a different order than described. It should also be recognized that the methods described above may be performed by hardware components or implemented as sequences of machine-executable instructions, which may be used to cause a machine, such as a general-purpose or special-purpose processor or logic circuits programmed with instructions, to perform the methods. These machine-executable instructions may be stored on one or more machine-readable media, such as CD-ROMs or other types of optical discs, floppy disks, ROMs, RAMs, EPROMs, EEPROMs, magnetic or optical cards, flash memory, or other types of machine-readable media suitable for storing electronic instructions. Alternatively, the methods may be performed by a combination of hardware and software.

Claims

Claim 1 A method comprising: a step of measuring the characteristics of a plasma; a step of monitoring the characteristics of the plasma during a process involving the plasma; a step of detecting the end of a stage of the process based on a comparison of the measured characteristics and a reference value; and a step of performing at least one action in response to the detection of the end of a stage of the process. Claim 2 A method according to claim 1, wherein the characteristic is the impedance of the plasma, the process is a plasma-enhanced chemical vapor deposition (PECVD) gapfill deposition process for a patterned sample, the stage of the process is a sidewall pinch-off stage, and the step of performing the at least one action comprises the step of automatically terminating the process after a duration of time measured from the detection. Claim 3 A method according to paragraph 2, wherein the patterned sample comprises a plurality of trenches, and at least one of the plurality of trenches comprises a dimension different from that of any other trench among the plurality of trenches. Claim 4 In paragraph 2, the gap-fill deposition process comprises the deposition of a gap-fill material comprising carbon, tungsten, or amorphous silicon. Claim 5 In claim 1, the method, wherein the reference value is based on conditions associated with the process. Claim 6 In claim 5, the conditions associated with the process include types of plasma gases, a flow rate of at least one plasma gas, a temperature, precursors associated with the process, at least one deposition rate, or at least one etching rate. Claim 7 A method according to claim 1, further comprising: a step of measuring the slope of the characteristic over time for a part of the process; and a step of changing at least one step in the sample patterning process based on the slope. Claim 8 A system comprising: a plasma system configured to perform deposition processes or etching processes; at least one sensor configured to measure the characteristics of the plasma within the plasma system; and a controller, wherein the controller comprises: One or more processors; and It includes one or more memory devices, The above one or more memory devices allow the processor: Operation of monitoring the characteristics during a process involving the above plasma; An operation to detect the termination of a stage of the process based on a comparison of the above characteristics and reference values; and A system comprising instructions executable by the processor to enable operations including performing at least one action in response to detecting the termination of a stage of the above process. Claim 9 In claim 8, the characteristic includes the impedance of the plasma, the process includes a plasma-enhanced chemical vapor deposition (PECVD) gap-fill deposition process for a patterned sample, the stage of the process is a sidewall pinch-off stage, and the operation of performing the at least one action includes an operation of automatically terminating the process after a duration measured from the detection. Claim 10 In claim 9, the patterned sample comprises a plurality of trenches, and at least one of the plurality of trenches comprises a dimension different from that of any other trench among the plurality of trenches, a system. Claim 11 In claim 9, the gap-fill deposition process comprises the deposition of a gap-fill material comprising carbon, tungsten, or amorphous silicon, in a system. Claim 12 In paragraph 8, the above reference value is based on conditions associated with the above process, in a system. Claim 13 In paragraph 12, the conditions associated with the process include types of plasma gases, a flow rate of at least one plasma gas, a temperature, precursors associated with the process, at least one deposition rate, or at least one etching rate, in a system. Claim 14 In claim 8, the above operations further comprise: an operation of measuring the slope of the characteristic over time for a part of the process; and an operation of changing at least one step in the sample patterning process based on the slope, the system. Claim 15 As one or more non-transient computer-readable media, when executed by one or more processors, the one or more processors: Operation of monitoring the measured characteristics of the plasma during a process involving the plasma; An operation to detect the termination of a stage of the process based on a comparison of the measured characteristics and reference values; and One or more non-transient computer-readable media comprising instructions that cause actions to be performed, including an action to perform at least one measure in response to detecting the termination of a stage of the above process. Claim 16 In paragraph 15, one or more non-transient computer-readable media, wherein the measured characteristic includes the impedance of the plasma, the process includes a plasma-enhanced chemical vapor deposition (PECVD) gap-fill deposition process for a patterned sample, the stage of the process includes a sidewall pinch-off stage, and the operation of performing the at least one action includes an operation of automatically terminating the process after a duration measured from the detection. Claim 17 In paragraph 16, the patterned sample comprises a plurality of trenches, and at least one of the plurality of trenches comprises a dimension different from that of any other trench among the plurality of trenches, one or more non-transient computer-readable media. Claim 18 In paragraph 16, the gap-fill deposition process comprises one or more non-transient computer-readable media comprising the deposition of a gap-fill material comprising carbon, tungsten, or amorphous silicon. Claim 19 In paragraph 15, the above reference value is one or more non-transient computer-readable media based on conditions associated with the process. Claim 20 In paragraph 19, the conditions associated with the process include types of plasma gases, a flow rate of at least one plasma gas, a temperature, precursors associated with the process, at least one deposition rate, or at least one etching rate, comprising one or more non-transient computer-readable media.

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