Process stage transition detection for plasma systems

Abstract

The goal of a gap-filling deposition process can be to form a relatively flat, transitional growth layer of gap-filling material above the top of the column. This relatively flat transitional growth layer can be formed by automatically stopping the gap-filling deposition process after detecting the end of a stage (e.g., the sidewall growth stage). Plasma characteristics, such as plasma impedance, can be monitored during the plasma process. Changes in these characteristics can be correlated with different stages of the process, such as those in the gap-filling process. When these characteristics indicate a change, a stage in the gap-filling process can be identified, and actions such as stopping the gap-filling process can be taken. This provides real-time monitoring of gap filling based on plasma characteristics, rather than measurements performed after the gap-filling process is complete.

Description

[Technical Field]

[0001] This application claims the rights and priority of U.S. non-provisional application No. 18 / 420,376, filed on January 23, 2024, entitled “PROCESS STAGE TRANSITION DETECTION FOR PLASMA SYSTEMS”, the entire contents of which are incorporated herein by reference for all purposes.

[0002] This disclosure provides a general description of the plasma system manufacturing process. More specifically, this disclosure describes in-situ stage transition detection for the plasma system manufacturing process. [Previous Technology]

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

[0004] Therefore, there is a need for improved systems and methods for producing high-quality components and structures. These and other needs are addressed by the technology of this invention. [Summary of the Invention]

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

[0006] In some embodiments, a system may include a plasma system configured to perform a deposition or etching process; at least one sensor configured to measure characteristics of a plasma in the plasma system; and a controller having one or more processors and one or more memory devices containing instructions executable by the processors to cause the processors to perform operations, including monitoring the characteristics during a process involving the plasma. These operations may also include detecting the endpoint of a stage of the process based on a comparison of the characteristics with a reference value; and performing at least one action in response to detecting the endpoint of the stage of the process.

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

[0008] In any embodiment, any and / or all of the following features may be implemented in any combination, not in a limited manner. The feature may include plasma impedance, wherein the process is a plasma-enhanced chemical vapor deposition (PECVD) gap-filling deposition process for a patterned sample, the stage of the process may include a sidewall pinch-off stage, and performing the at least one action may include automatically ending the process after a duration from the start of the measurement. The patterned sample may include a plurality of trenches, and at least one of the trenches may include a size different from the size of any other trench among the plurality of trenches. The gap-filling deposition process may include the deposition of a gap-filling material comprising carbon, tungsten, or amorphous silicon. The reference value may be based on conditions associated with the process. Such conditions associated with the process may include the type of plasma gas, the flow rate of at least one plasma gas, temperature, precursors involved in the process, at least one deposition rate, or at least one etch rate. The slope of this characteristic over time can be measured for a portion of the process, and at least one step in the sample patterning process can be changed based on this slope.

Implementation Method

[0017] Certain aspects and examples of this disclosure relate to stage transition detection in manufacturing processes involving plasma systems. For example, the manufacturing process may be a gap-filling deposition process comprising patterned samples of pillars and trenches. The pillars and trenches may include different sizes, which can pose challenges to optimizing the deposition process. The goal of the gap-filling deposition process may be to form a relatively flat overgrowth layer of gap-filling material above the top of the pillars. This relatively flat overgrowth layer can be formed by automatically stopping the gap-filling deposition process after a certain duration following the detection of the endpoint of a stage of the manufacturing process (e.g., the sidewall growth stage). Characteristics of the plasma, such as plasma impedance, can be monitored during the plasma process. Changes in these characteristics may be associated with different stages of the process, such as different stages of the gap-filling process. When a characteristic indicates a change, a stage of the gap-filling process can be identified, and actions such as stopping the gap-filling process can be taken. This provides an in-situ monitoring of gap filling based on plasma characteristics, rather than based on invasive measurements or measurements performed after the gap filling process is complete.

[0018] After describing a general configuration of a chamber in which the plasma processing operations discussed below can be performed according to some embodiments of the technology of the present invention, specific methods may be discussed. It should be understood that the technology of the present invention is not intended to be limited to the specific membrane, chamber or process discussed, as the described technology can be used to increase the number of membrane formation processes and is applicable to a variety of processing chambers and operations.

[0019] Figure 1 shows a cross-sectional view of an exemplary processing chamber 100 according to some embodiments of the present invention. This figure illustrates an overview of a system incorporated into one or more aspects of the present invention, and / or a system specifically configured to perform one or more operations according to embodiments of the present invention. Further details of the chamber 100 or the performed methods will be described below. The chamber 100 can be used to form films, etch material layers, form other material layers, or combinations thereof; however, it will be understood that deposition and etching methods can be similarly performed in any chamber in which deposition and etching processes can occur. 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. A substrate 103 may be provided to the processing volume 120 via an opening 126, which may be sealed using a slit valve or door in a conventional manner for processing. During processing, the substrate 103 may be sealed onto the surface 105 of the substrate support. In some embodiments, the substrate support 104 may be rotatable along a vertical axis (the shaft 144 of the substrate support 104 may be located at this vertical axis), or it may be stationary. Alternatively, during the deposition process, the substrate support 104 may be lifted to rotate as needed.

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

[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 from conductive and non-conductive components. For example, the body of the gas distributor 112 may be conductive, while the panel of the gas distributor 112 may be non-conductive. The gas distributor 112 may be powered, for example, by a first power source 142 as shown in Figure 1, or in some embodiments, the gas distributor 112 may be coupled to the ground.

[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, perforated plate, mesh, wire mesh, or any other distributed arrangement of conductive elements. The first electrode 122 may be a tuning electrode and may be coupled to the tuning circuit 136 via, for example, a conduit 146 (e.g., a cable with a selected resistance such as 50 ohms) disposed in a shaft 144 of the substrate support 104. The tuning circuit 136 may have an electronic sensor 138 and an electronic controller 140, which may be a variable capacitor. The electronic sensor 138 may be a voltage or current sensor and may be coupled to the electronic controller 140 to provide further control over the plasma conditions in the processing volume 120.

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

[0024] The cover assembly 106 and substrate support 104 of Figure 1 can be used with any processing chamber for plasma or thermal processing. In operation, the processing chamber 100 can provide immediate control over plasma conditions in the processing volume 120, such as via a system controller 101, which may be contained within the processor 107. The substrate 103 can be mounted on the substrate support 104, and process gases can flow through the cover assembly 106 via inlet 114 according to any desired flow pattern. The gases can exit the processing chamber 100 via outlet 152. Electricity can be coupled to the gas distributor 112 to establish plasma in the processing volume 120. In some embodiments, a second electrode 124 can be used to subject the substrate to an electrical bias.

[0025] After the plasma in the treatment volume 120 is activated, a potential difference can be established between the plasma and the first electrode 122. The electronic controller 140 can then be used to adjust the flow properties of the ground path represented by the tuning circuit 136. A setpoint can be fed to the tuning circuit 136 to provide independent control over the deposition rate and the uniformity of plasma density from the center to the edge. In embodiments where the electronic controller may be a variable capacitor, the electronic sensor can independently adjust the variable capacitor to maximize the deposition rate and minimize thickness non-uniformity.

[0026] The tuning circuit 136 may have a variable impedance, which can be adjusted using the electronic controller 140. In the case where the electronic controller 140 is a variable capacitor, the capacitance range of each of the variable capacitors can be selected to provide an impedance range. This range may depend on the frequency and voltage characteristics of the plasma, which may have minimum values ​​within the capacitance range of each variable capacitor. Therefore, when the capacitance of the electronic controller 140 is at its minimum or maximum value, the impedance of the tuning circuit 136 may be high, resulting in a plasma shape with minimal air 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 air coverage of the plasma can increase to its maximum value, effectively covering 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 wall and the air coverage of the substrate support may decrease.

[0027] Electronic sensor 138 can be used to tune the tuning circuit 136 in a closed loop. Depending on the type of sensor used, a current or voltage setpoint can be installed in each sensor, and the sensor can have control software that determines the adjustment of electronic controller 140 to minimize deviation from the setpoint. Therefore, the plasma shape can be selected and dynamically controlled during processing. It should be understood that although the foregoing discussion is based on electronic controller 140, which may be a variable capacitor, any electronic component with adjustable characteristics can be used to provide adjustable impedance for tuning circuit 136.

[0028] In some embodiments of the present invention, the processing chamber 100 may be used for processing methods that may include bottom-up deposition of material for a semiconductor structure. It should be understood that the described chamber should not be considered limiting, and any chamber that can be configured to perform the operations described may be used similarly.

[0029] Figure 2 shows a schematic cross-sectional view of a patterned sample 200 that may be incorporated into a process according to some embodiments. The patterned sample 200 may include a substrate 206 and pillars, such as pillars 202A, 202B, and 202C. Although three pillars are shown in Figure 2, the patterned sample 200 may include any number of pillars. Each of these pillars may be formed by a plurality of alternating deposited layers, such as layer 203 or layer 204. Layers 203 and 204 may be deposited layers in 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 several alternating deposited layers are shown in Figure 2, only layers 203 and 204 are labeled for simplicity. These alternating deposited layers may have layer thicknesses. For example, layer 203 may have a thickness t1, and layer 204 may have a thickness t2. In some instances, each of these alternating layers may have the same thickness (t1=t2).

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

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

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

[0033] In different regions of the patterned sample 200, the height h, width w, or both may have different values. For example, the patterned sample 200 may be divided into four quadrants. In the first quadrant, a first subgroup of pillars may have a width of 10 nm and a height of 5 micrometers. In the second quadrant, a second subgroup of pillars may have a width of 50 nm and a height of 25 micrometers. The third quadrant may include a third subgroup of pillars with a width of 20 nm and a height of 10 micrometers. In the fourth quadrant, a fourth subgroup of pillars may have a width of 24 nm and a height of 10 micrometers.

[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 process chamber 100 from Figure 1), and the trenches of the patterned sample 200 can be filled with a filling material during a plasma-enhanced chemical vapor deposition (PECVD) process. During the PECVD process, the start and end points of the PECVD process stages can be detected by monitoring changes in plasma characteristics (e.g., impedance, etc.) over time.

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

[0036] During the initial stage of the gap-filling process, gap-filling material 315 may accumulate in the trench and on the top of the pillar. The gap-filling material 315 formed above the pillar may be referred to as overgrowth. The deposition of gap-filling material 315 in the trench can be described as sidewall growth or sidewall deposition. For example, in the first cross-sectional view 302, most of the gap-filling material 315 shown in the trench between pillars 202A and 202B is accumulated on the side of the trench. Some of the gap-filling material 315 is formed on the right side of pillar 202A and grows toward the left side of pillar 202B. In addition, some of the gap-filling material 315 in the trench is formed on the left side of pillar 202B and grows toward the right side of pillar 202A. The initial stage of the gap-filling deposition process can be described as a sidewall formation or sidewall growth stage.

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

[0038] Third cross-sectional view 306 shows a patterned sample during the second stage or pinch-off stage of the gap-filling deposition process. During the pinch-off stage, numerous trenches undergo pinch-off accumulation. During this second stage, some trenches that experienced pinch-off earlier may accumulate additional overgrowth. Fourth cross-sectional view 308 shows a patterned sample during the transition from the second stage to the third stage of the gap-filling deposition process. The third stage may begin once whenever (or almost whenever) a trench experiences pinch-off. The third stage may be the stage in which all trenches have undergone accumulation of overgrowth. Fifth cross-sectional view 310 depicts a patterned sample during the third stage of the gap-filling deposition process.

[0039] Figure 4 is a graph 400 showing the time-related characteristics of plasma during a gap-filling deposition process according to some embodiments. Graph 400 may include two curves. A first curve 402 represents the plasma characteristics when a trench in a patterned sample is filled by gap filling. For example, the plasma characteristic may be the plasma impedance value. The graph may also include a second curve 404, which represents a constant reference value for the plasma characteristics. This constant reference value may be associated with the plasma characteristics when an unpatterned sample is present. The characteristics represented by the second curve 404 may be based on the conditions present during the gap-filling deposition process for a patterned sample.

[0040] The first curve 402 can indicate the time correlation of various stages in the gap-filling deposition process. The first transition time 406 can indicate the time when the slope of the first curve 402 suddenly changes from a near-zero value to a near-constant negative value. The first transition time 406 can indicate the transition from the first stage 410 of the gap-filling process to the second stage 412 of the gap-filling process. The first stage 410 can be associated with sidewall growth and can be clearly seen in the first curve within a first time period before the first transition time. The second stage 412 of the gap-filling process can be referred to as the pinch-off stage of the gap-filling process. The second stage 412 can be associated with the region in the curve 400 where the first curve 402 experiences a near-constant negative slope, the number of grooves accumulated by the pinch-off in the patterned sample, and the characteristics of the plasma approaching the reference value of the second curve 404. The magnitude of the near-constant negative slope can indicate the degree of uniformity of the patterned sample. The more uniform the patterned sample, the steeper the near-constant negative slope can be. More uniformity can mean less variation in groove width, groove height, or a combination of these two dimensions. The second stage 412 may end when all (or almost all) of the grooves have been clamped.

[0041] The second transition time 408 indicates the time when the slope of the first curve 402 suddenly changes from a nearly constant negative value to nearly zero. At the second transition time, the first curve 402 and the second curve 404 are aligned, and the plasma characteristics match the reference value. The second transition time 408 indicates the end of the pinch-off stage of the gap-filling deposition process. The second transition time 408 can be detected by comparing the measured characteristic value (the value of the first curve 402) with the reference value from the second curve 404. If the comparison indicates that the two values ​​match (within a predetermined safety factor), the end of the pinch-off stage can be detected. Once the pinch-off stage ends, the third stage of overgrowth accumulation of all trenches can begin. The process can automatically end after the predetermined time has elapsed since the second transition time.

[0042] Figure 5 is a cross-sectional transmission electron microscope (TEM) image 500 of a patterned sample having grooves partially filled with gap filler material 515 according to some embodiments. TEM image 500 shows a snapshot of multiple pillars (including pillar 502) during the sidewall growth stage of the gap filler deposition process. Although several pillars are shown in Figure 5, only pillar 502 is labeled for simplicity. Due to the absence of pinch-offs, the sidewall growth stage is readily apparent in TEM image 500. In TEM image 500, the sidewall of each pillar does not appear to touch the sidewall of any other pillar.

[0043] The TEM image 500 also includes a boundary line 520. The boundary line 520 indicates the top boundary of each of the pillars. Any gap-filling material 515 accumulated above the boundary line 520 can be considered an overload. In the example shown in Figure 5, the pillar width is approximately 50 nm, the visible portion of the pillar height is approximately 700 nm, the overload height is approximately 100 nm, and the trench width is approximately 130 nm. In Figure 5, the sidewall growth appears to vary slightly with the pillar and depth, and has a range of approximately 20 nm to 40 nm.

[0044] Figure 6 is a flowchart of an example of a process 600 for detecting the end point of a stage in a deposition process, according to some aspects of this disclosure. Operations in the flowchart begin with block 610 and can be performed in the indicated order or any suitable order. Other examples may involve more operations, fewer operations, different operations, or a different order of operations than shown in Figure 6. Some or all of the steps of process 600 can be performed by a processor. Although process 600 is described relative to a deposition process for illustrative purposes, the description of process 600 included in this disclosure enables those skilled in the art to apply the methods and systems to etching processes as well.

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

[0046] At block 620, process 600 involves monitoring plasma impedance during a deposition process for a patterned sample. The deposition process may be a backfill deposition process, which involves depositing backfill material into trenches on the patterned sample. The trenches of the patterned sample may include different sizes. For example, a first region of the patterned sample may include pillars with a width of 100 nm, and a second region of the patterned sample may include pillars with a width of 200 nm. The backfill material may include carbon, tungsten, amorphous silicon, etc. Monitoring impedance may involve creating a graph of plasma impedance versus time. The curve on the impedance versus time graph may be similar to curve 402 on graph 400 of Figure 4. The curve may include a region with a constant slope, which may be associated with a stage of the backfill deposition process. For example, a portion of the graph with a constant negative slope may be associated with a sidewall pinch-off stage of the backfill deposition process. The magnitude of the negative slope may be a measure of the uniformity of the patterned sample. In some instances, the value of a negative slope can be measured, and the sample patterning process can be modified based on the measured slope value.

[0047] At block 630, process 600 involves detecting the end of a stage of the deposition process based on conditions such as measured impedance. This stage may be a sidewall pinch-off stage. The end of the sidewall pinch-off stage can be detected when the measured impedance of the plasma matches a reference value or reaches a threshold or changes in slope. The reference value may be an impedance value associated with an unpatterned sample. For example, when the patterned sample has a silicon substrate, the reference value can 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 the type of plasma gas, the flow rate of at least one of the gases, the co-flow rate of the plasma gas and the deposition precursor, temperature, the precursor involved in the deposition process, at least one deposition rate, or at least one etch rate. In some instances, the end of the sidewall pinch-off stage may be detected based on a change in the slope of a monitored curve of plasma impedance versus time.

[0048] In block 640, process 600 involves performing an action such as automatically ending the deposition process after a duration measured from the end of this stage of the self-detection deposition process. This action can be performed in response to detecting the end of a stage of the deposition process. This stage can be a sidewall clamping stage. The duration can be a predetermined amount of time and can be based on the deposition rate of the backfill material or the target height of the overgrowth layer. The overgrowth layer can be a layer of backfill material accumulated above the top of the column of the patterned sample. The duration can be the amount of time elapsed before a smooth overgrowth layer is formed.

[0049] Figure 7 illustrates an exemplary computer system 700 in which various embodiments may be implemented. The computer system 700 can be used to implement any of the computer systems described above. As shown, the computer system 700 includes a processing unit 704 that communicates with a plurality 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 a tangible computer-readable storage medium 722 and system memory 710.

[0050] Bus subsystem 702 provides a mechanism for enabling various components and subsystems of computer system 700 to communicate with each other as intended. Although bus subsystem 702 is schematically shown as a single bus, alternative embodiments of the bus subsystem may utilize multiple buses. Bus subsystem 702 may be any of several types of bus structures, including memory bus or memory controller, peripheral bus, and local bus using any of a variety of bus architectures. For example, these architectures may include Industry Standard Architecture (ISA) buses, Micro Channel Architecture (MCA) buses, Enhanced ISA (EISA) buses, Video Electronics Standards Association (VESA) local buses, EtherCAT buses, and Peripheral Component Interconnect (PCI) buses, which may be implemented as mezzanine buses manufactured to conform 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 microcontroller), controls the operation of the computer system 700. The processing unit 704 may include one or more processors. These processors may include single-core or multi-core processors. In some embodiments, the processing unit 704 may be implemented as one or more independent processing units 732 and / or 734, wherein each processing unit includes a single-core or multi-core processor. 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 multiple programs in response to code, and may maintain multiple concurrently executing programs or processes. At any given time, part or all of the code to be executed may reside in one or more processors 704 and / or storage subsystem 718. With appropriate programming, the processors 704 may provide the various functions described above. The computer system 700 may further include a processing acceleration unit 706, which may include a digital signal processor (DSP), a dedicated processor, and / or the like.

[0053] The I / O subsystem 708 may include user interface input devices and user interface output devices. User interface input devices may include keyboards, pointing devices such as mice or trackballs, touchpads or touch screens integrated into displays, scroll wheels, selection wheels, dials, buttons, switches, keypads, audio input devices with voice command recognition systems, microphones, and other types of input devices.

[0054] User interface input devices may also include (but are not limited to) three-dimensional (3D) mice, joysticks or pointing sticks, graphics tablets, and audio / video devices such as speakers, digital cameras, digital camcorders, webcams, image scanners, fingerprint scanners, barcode readers, 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, etc.). Display subsystems may be cathode ray tubes (CRTs), flat panel devices such as those using liquid crystal displays (LCDs) or plasma displays, projection devices, touch screens, and the like. Generally, the term "output device" is used to include all possible types of elements and mechanisms for outputting information from computer system 700 to the user or other computers. For example, user interface output devices may include, but are not limited to, various display devices that visually convey text, graphics, and audio / video information, such as monitors, printers, speakers, headphones, car navigation systems, plotters, voice output devices, and modems.

[0055] The computer system 700 may include a storage subsystem 718, which includes software components and is shown to be currently located in system memory 710. System memory 710 may store program instructions that can be loaded and executed on 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 (such as random access memory (RAM)) and / or non-volatile (such as read-only memory (ROM), flash memory, etc.). RAM typically contains data and / or program modules that the processing unit 704 can immediately access and / or is currently operating and executing. In some embodiments, the system memory 710 may include various types of memory, such as static random access memory (SRAM) or dynamic random access memory (DRAM). In some embodiments, the basic input / output system (BIOS) may typically be stored in ROM, containing basic routines such as those that help transfer information between components within the computer system 700 during startup. By way of example, and not as a limitation, system memory 710 also illustrates applications 712, which may include client applications, web browsers, middleware applications, relational database management systems (RDBMS), program data 714, and operating system 716. By way of example, operating system 716 may include a mobile operating system for use on mobile devices.

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

[0058] The storage subsystem 700 may also include a computer-readable storage media reader 720, which may be further connected to a computer-readable storage media 822. Together with and as appropriate with system memory 710, the computer-readable storage media 722 may comprehensively represent remote, local, fixed and / or removable storage devices plus storage media for temporarily and / or more permanently containing, storing, transmitting and retrieving computer-readable information.

[0059] The computer-readable storage medium 722 containing code or code portions may also include any suitable media, including storage media and communication media, such as, but not limited to, volatile and non-volatile, removable and non-removable media implemented in any method or technology 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 technologies, CD-ROM, digital versatile disk (DVD), or other optical storage, cassette tape, magnetic tape, magnetic disk storage or other magnetic storage devices, or other tangible computer-readable media. This may also include intangible computer-readable media, such as data signals, data transmissions, or any other media that can be used to transmit desired information and is accessible by the computing system 700.

[0060] By way of example, computer-readable storage media 722 may include: a hard disk drive that reads from or writes to a non-removable, non-volatile magnetic medium; 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 is not limited to, flash memory cards, universal serial bus (USB) flash drives, secure digital (SD) cards, DVD disks, digital video tapes, and the like. Computer-readable storage media 722 may also include: solid-state drives (SSDs) based on non-volatile memory, such as flash memory-based SSDs, enterprise-class flash drives, solid-state ROMs, and the like; SSDs based on volatile memory, such as solid-state RAM, dynamic RAM, static RAM, DRAM-based SSDs, magnetoresistive RAM (MRAM) SSDs; and hybrid SSDs that use a combination of DRAM-based and flash memory-based SSDs. The disk drive and its associated computer-readable media provide the computer system 700 with non-volatile storage of computer-readable instructions, data structures, program modules, and other data.

[0061] The communication subsystem 724 provides an interface with other computer systems and networks. The communication subsystem 724 acts as an interface for receiving data from other systems and transmitting data from computer system 700 to other systems. For example, the communication subsystem 724 enables computer system 700 to connect to one or more devices via the Internet. In some embodiments, the communication subsystem 724 may include: a radio frequency (RF) transceiver component for accessing wireless voice and / or data networks (e.g., using cellular telephone technology, advanced data network technologies such as 3G, 4G, or EDGE (Enhanced Data Rate for Global Evolution)); WiFi (IEEE 802.11 series standards, or other mobile communication technologies, or any combination thereof); a global positioning system (GPS) receiver component; and / or other components. In some embodiments, in addition to or instead of a wireless interface, the communication subsystem 724 may provide a wired network connection (e.g., Ethernet).

[0062] Additionally, the communication subsystem 724 may also be configured to receive data in the form of a continuous data stream, which may include event streams 728 and / or event updates 730 of real-time events, which may be continuous or unbounded in nature and without a definite endpoint. Examples of applications that generate continuous data may include, for example, sensor data applications, financial tickets, network performance measurement tools (e.g., network monitoring and traffic management applications), point-to-point streaming analysis tools, vehicle traffic monitoring, and the like.

[0063] The communication subsystem 724 may also be configured to feed structured and / or unstructured data 726, event streams 728, event updates 730 and the like to one or more databases, which may communicate 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 handheld portable devices (e.g., smartphones, tablet computers, etc.), PCs, workstations, mainframes, controllers, server racks, or any other data processing system.

[0065] Due to the constantly evolving nature of computers and networks, the description of the computer system 700 depicted in the figures is intended only as a specific example. Many other configurations with more or fewer components than the system depicted in the figures are possible. For example, custom hardware may also be used, and / or specific elements may be implemented using hardware, firmware, software (including applets), or combinations thereof. Additionally, connections to other computing devices (such as network input / output devices) may be employed. Other manners and / or methods for implementing various embodiments will become apparent from the disclosure and teaching provided herein.

[0066] As used herein, the terms “about” or “generally” or “substantially” can be interpreted as within the range that a person of ordinary skill would expect from this specification.

[0067] In the foregoing description, numerous specific details have been set forth for illustrative purposes in order 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 instances, well-known structures and apparatuses are shown in block diagram form.

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

[0069] Specific details are set forth 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 have been shown as parts in block diagram form so as not to obscure the embodiments with unnecessary details. In other instances, well-known circuits, processes, algorithms, structures, and techniques may have been shown without unnecessary details in order to avoid obscuring the embodiments.

[0070] Furthermore, it should be noted that some embodiments may be described as processes depicted as flowcharts, flow diagrams, data flow diagrams, structural diagrams, or block diagrams. Although the flowchart may describe operations as sequential processes, many of these operations may be performed in parallel or simultaneously. Additionally, the order of operations may be rearranged. A process terminates when its operations are completed, but may have additional steps not included in the diagram. A process may correspond to a method, function, program, subroutine, etc. When a process corresponds to a function, its termination may correspond to the function returning to the calling function or the main function.

[0071] The term "computer-readable media" includes, but is not limited to, portable or fixed storage devices, optical storage devices, wireless channels, and various other media capable of storing, containing, or carrying instructions and / or data. A code segment or machine-executable instruction may represent a program, function, subroutine, program, regular expression, sub-regular expression, module, software suite, class, or any combination of instructions, data structures, or program descriptions. 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 transferred by any suitable means, including memory sharing, message passing, symbol passing, network transmission, etc.

[0072] Additionally, embodiments may be implemented using hardware, software, firmware, intermediates, microcode, hardware description languages, or any combination thereof. When implemented using software, firmware, intermediates, or microcode, program code or code segments for performing necessary tasks may be stored in a machine-readable medium. (Several) processors may perform the necessary tasks.

[0073] In the foregoing specification, features have been described with reference to specific embodiments, but it should be understood that not all embodiments are limited thereto. Various features and styles of some embodiments may be used individually or in combination. Furthermore, without departing from the broader spirit and scope of this specification, embodiments may be used in any number of environments and applications beyond those described herein. Therefore, the specification and drawings should be considered illustrative rather than restrictive.

[0074] Additionally, for illustrative purposes, the methods are described in a specific order. It should be understood that in alternative embodiments, the methods may be performed in a different order than described. It should also be understood that the methods described above may be executed by hardware components or may be embodied in a sequence of machine-executable instructions that can be used to cause a machine (such as a general-purpose or special-purpose processor or logic circuitry programmed by instructions) to execute 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 memory cards, flash memory, or other types of machine-readable media suitable for storing electronic instructions. Alternatively, the methods may be executed by a combination of hardware and software. [Simplified Explanation of the Diagram]

[0009] A further understanding of the nature and advantages of the various embodiments can be achieved by referring to the remainder of this specification and the drawings, wherein the same element symbols are used throughout the drawings to represent similar parts. In some cases, sublabels are associated with element symbols to indicate one of a plurality of similar parts. When element symbols are referenced without specifying existing sublabels, they are intended to represent all such plurality of similar parts.

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

[0011] Figure 2 shows a schematic cross-sectional view of a patterned sample that can be incorporated into the process according to some embodiments.

[0012] Figure 3 is a schematic diagram of a cross-sectional view of a patterned sample during different parts of a gap-filling deposition process according to some embodiments.

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

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

[0015] Figure 6 is a flowchart of an example of a process for detecting the end point of a stage in a deposition process according to some of the states disclosed herein.

[0016] Figure 7 illustrates an exemplary computer system in which various embodiments may be implemented. [Biomaterial Storage]

[0076] Domestic Deposit Information (Please note in order of deposit institution, date, and number) None

[0077] Overseas Deposit Information (Please note in the order of deposit country, institution, date, and number) None

Claims

1. A method for stage transition detection, comprising the steps of: measuring a characteristic of a plasma; monitoring the characteristic of the plasma during a process involving the plasma; detecting an end point of a stage of the process based on a comparison of the measured characteristic with a reference value; and performing at least one action in response to detecting the end point of the stage of the process, wherein the characteristic is an impedance of the plasma, wherein the process is a plasma-enhanced chemical vapor deposition (PECVD) gap-filling deposition process for a patterned sample, the stage of the process being a sidewall pinch-off stage, and the step of performing the at least one action comprising the step of: automatically ending the process after a duration of measurement from the start of the detection.

2. The method as described in claim 1, wherein the patterned sample comprises a plurality of grooves, and at least one of the grooves includes a dimension different from that of any other groove among the grooves.

3. The method as described in claim 1, wherein the gap-filling deposition process comprises the deposition of a gap-filling material comprising carbon, tungsten, or amorphous silicon.

4. The method as described in claim 1, wherein the reference value is based on conditions associated with the process.

5. The method as described in claim 4, wherein the conditions associated with the process include the type of plasma gas, a flow rate of at least one plasma gas, a temperature, a precursor involved in the process, at least one deposition rate, or at least one etching rate.

6. The method as described in claim 1 further comprises the following steps: measuring a slope of the characteristic over time for a portion of the process; and changing at least one step in a patterning process based on the slope.

7. A system for stage transition detection, comprising: a plasma system configured to perform a deposition process or an etching process; at least one sensor configured to measure a characteristic of a plasma in the plasma system; and a controller comprising: one or more processors; and one or more memory devices including instructions executable by the processors to cause the processors to perform operations including: monitoring the characteristic during a process involving the plasma; detecting an end point of a stage of the process based on a comparison of the characteristic with a reference value; and performing at least one action in response to detecting the end point of the stage of the process; wherein the characteristic includes an impedance of the plasma, the process includes a plasma-enhanced chemical vapor deposition (PECVD) gap-filling deposition process for a patterned sample, the stage of the process being a sidewall pinch-off stage, and the operation of performing the at least one action includes automatically ending the process after a duration of measurement from the start of the detection.

8. The system as claimed in claim 7, wherein the patterned sample comprises a plurality of grooves, and at least one of the grooves includes a dimension different from that of any other groove among the grooves.

9. The system as claimed in claim 7, wherein the gap-filling deposition process includes the deposition of a gap-filling material comprising carbon, tungsten, or amorphous silicon.

10. The system as described in claim 7, wherein the reference value is based on conditions associated with the process.

11. The system as claimed in claim 10, wherein the conditions associated with the process include the type of plasma gas, a flow rate of at least one plasma gas, a temperature, a precursor involved in the process, at least one deposition rate, or at least one etching rate.

12. The system as claimed in claim 7, wherein the operations further comprise: measuring a slope of the characteristic over time for a portion of the process; and changing at least one step in a patterning process based on the slope.

13. One or more non-transitory computer-readable media containing instructions that, when executed by one or more processors, cause the one or more processors to perform operations, including: The process involves monitoring a measured characteristic of a plasma during a process involving a plasma; detecting an endpoint of a stage of the process based on a comparison of the measured characteristic with a reference value; and performing at least one action in response to the detection of the endpoint of the stage of the process; wherein the measured characteristic includes an impedance of the plasma, the process includes a plasma-enhanced chemical vapor deposition (PECVD) gap-filling 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 automatically ending the process after a duration of measurement from the start of the detection.

14. One or more non-transitory computer-readable media as described in claim 13, wherein the patterned sample comprises a plurality of grooves, and at least one of the grooves includes a size different from a size of any other groove among the grooves.

15. One or more non-transitory computer-readable media as described in claim 13, wherein the gap-filling deposition process comprises a deposition of a gap-filling material comprising carbon, tungsten, or amorphous silicon.

16. One or more non-transitory computer-readable media as described in claim 13, wherein the reference value is based on conditions associated with the process.

17. One or more non-transitory computer-readable media as described in claim 16, wherein the conditions associated with the process include the type of plasma gas, the flow rate of at least one plasma gas, temperature, precursors involved in the process, at least one deposition rate, or at least one etch rate.

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