Profiling in staircase conformality extraction and a tool for the same

Abstract

A method for determining penetration depth of a thin film process precursor, comprising providing an insert (100), arranging the insert (100) to contact a substrate (200) to form a plurality of spaces (101) in between the insert (100) and the substrate (200), and feeding the precursor(s) into the formed spaces (101) to determine the penetration depth of the precursor.

Description

[0001] PROFILING IN STAIRCASE CONFORMALITY EXTRACTION AND A TOOL FOR THE SAME

[0002] TECHNICAL FIELD

[0003] The present disclosure generally relates to the field of semiconductors and substrate processing. The disclosure relates particularly, though not exclusively, to process control and monitoring of a thin film deposition process, such as atomic layer deposition (ALD), and more specifically to a method for depositing staircase conformality profile inside High Aspect Ratio structures (HAR) according to the present disclosure of a method to analyze and extract parameters describing the process conformality, including such as penetration depth. The present disclosure relates also to a HAR test wafer holder in the method of the present disclosure.

[0004] BACKGROUND

[0005] This section illustrates useful background information without admission of any technique described herein representative of the state of the art.

[0006] In the field of semiconductors and substrate processing, thin film deposition is used in almost every device. The atomic layer deposition (ALD) is vastly utilized as a thin film deposition method due to its conformal coating of various 3D shapes. Especially, ALD is advantageous as a deposition method for high aspect ratio (HAR) structures.

[0007] However, testing and quantifying the conformality as part of process control may be time consuming and expensive. The conventional testing procedure may comprise for instance fabricating a suitable test sample, depositing a thin film on the test sample, cutting, and preparing an appropriate sample for scanning electron microscopy (SEM) or transmission electron microscopy (TEM) imaging and analyzing the results from SEM and TEM imaging. The duration of the conventional procedure described above may be weeks and the estimated costs of such basic process control procedure thousands of euros.

[0008] Problems related to analysis of High Aspect Ratio structures (HAR), are notoriously inefficient to analyze as such according to the known methods. Currently, a single, expensive test structure has been used for a single run as such. These structures are of microscopic scale and thus require expensive analysis methods, and when met such, a staircase profile is still challenging to have detect in these structures, which may be also slow and expensive, but also inefficient.

[0009] SUMMARY

[0010] The appended claims define the scope of protection. Any examples and technical descriptions of apparatuses, products and / or methods in the description and / or drawings not covered by the claims are presented not as embodiments of the invention but as background art or examples useful for understanding the invention.

[0011] It is an object of certain embodiments of the invention according to the present disclosure to provide an improved process control and / or monitoring and subsequent analysis method for thin film deposition or at least to provide an alternative solution to existing technology, to be used in analyzing structures and extracting parameters that describe the process conformality.

[0012] As the current state of the art relies on doing a single deposition as such and then performing the analysis to it, to find the penetration depth (conformality), contrary to that, according to the novel method according to the present disclosure of embodiments, multiple runs can be deposited on a single substrate, so that each run has a characteristic penetration depth. In addition, an embodied macroscopic test structure makes the penetration depth of each process recipe easily separable, enabling the multirun analysis to determine the optimal penetration depth of the thin film for a specific process recipe.

[0013] Without limiting the scope of the present disclosure and the interpretation of the patent claims, certain technical effects of one or more of the example embodiments disclosed herein are listed in the following. According to an aspect of the present disclosure, a technical effect of embodiments of the invention comprises making a thin film deposition process control and monitoring faster and cheaper. In addition, according to a further synergic aspect of the present disclosure, a further synergic technical effect of certain embodiments is reducing the downtime in a production due to faster process control and monitoring. In addition, according to a further synergic aspect of the present disclosure, a further technical synergic effect of embodiments is obtained for adjusting the thin film deposition process more agile. In addition, according to even a further synergic aspect of the present disclosure, a further technical effect of certain embodiments is allowing a quantitative visual inspection in the process control and monitoring. Various embodiments have been presented in the outstanding disclosure. It should be appreciated that in this document, words comprise, include, and contain are each used as open-ended expressions with no intended exclusivity.

[0014] A method for determining a penetration depth of a thin film, according to the present disclosure has been indicated in an independent Claim 1.

[0015] An insert configured to contact a substrate to form a plurality of spaces in between the insert and the substrate for determining penetration depths according to the present disclosure has been indicated in an independent Claim 15.

[0016] A substrate holder according to the present disclosure has been indicated in an independent Claim 18.

[0017] An apparatus according to the present disclosure has been indicated in an independent Claim 20.

[0018] A computer program comprising a computer executable program code according to the present disclosure has been indicated in an independent Claim 21.

[0019] A use of computer program according to the present disclosure has been indicated in an independent Claim 23.

[0020] According to certain embodiments of the present disclosure, the method comprises feeding the precursor(s) into the formed spaces in a reaction chamber of the deposition apparatus housing the substrate and the surface of the substrate holder.

[0021] In addition, the method according to the certain embodiments of the present disclosure can further comprise feeding the precursor(s) into the formed spaces by using an atomic layer deposition (ALD) process recipe and / or the method comprises determining the penetration depth of the film formed on a backside of the substrate.

[0022] According to certain embodiments of the present disclosure, the method comprises determination of surface features formed on the surface of the substrate holder that are preferably high aspect ratio structures.

[0023] According to certain embodiments of the present disclosure the method comprises determination of spaces formed between the substrate and the surface of the substrate holder that are elongated spaces open at their one end, closed at their other end, and confined by the substrate and / or the surface of the substrate holder along their width.

[0024] According to certain embodiments of the present disclosure, the method comprises determination of such surface features that are formed on the surface of the substrate holder comprising grooves, which grooves are configured to form said spaces in between the substrate and the surface of the substrate holder when the substrate is placed on the substrate holder.

[0025] According to certain embodiments of the present disclosure, the method can be used in determination of spaces that have varying widths or varying heights. According to a further variant the method can be applied to such spaces that are separate from each other, preventing the precursor(s) from flowing from one space directly into an adjacent space.

[0026] According to certain embodiments of the present disclosure, the method comprises feeding precursors into the spaces through said aperture or recess, that is connected to a central aperture or a central recess formed in its surface, wherein said aperture or recess being connected to the spaces to allow precursor feed.

[0027] According to certain embodiment variants of the present disclosure, in the embodied method a precursor(s) flow within the spaces via diffusion.

[0028] According to certain embodiments of the present disclosure, in the method, such determining comprises: analyzing obtained measurement data by at least one processor; and providing an operator with measurement results based on the analysis.

[0029] According to certain embodiments, when obtaining results, including multiple conformality results, from the measurement of the thin film formed on the substrate the results are used in adjusting the thin film process according to the obtained results. According to an embodiment variant, the multiple conformality results enable adjustment of the thin film process parameters selected from the group including: flow, pulses, deposition temperature or process pressure.

[0030] An insert according to the present disclosure is configured to contact a substrate to form a plurality of spaces in between the insert and the substrate for determining penetration depths of thin film process precursor(s) with the method according to embodiments of the present disclosure directed to embodiments of the disclosed method. According to certain embodiments of the present disclosure, an embodied insert comprises grooves configured to form said spaces when the insert and the substrate contact each other.

[0031] According to certain embodiments of the present disclosure, an embodied insert is integrated to a substrate holder.

[0032] A substrate holder according to the present disclosure is comprising a holding part to hold the substrate in a process chamber or a part thereof, and an integrated insert part to the substrate holder.

[0033] According to certain embodiments of the present disclosure the substrate holder comprises an integrated insert part to the substrate holder, so that facilitating a wafer to land on said substrate holder, on said insert part.

[0034] An apparatus according to an embodiment of the present disclosure comprises at least one processor, and at least one memory including computer program code as a software, wherein the at least one memory and the computer program code are configured, with the at least one processor, to make the apparatus to perform: feeding of precursor(s) into a plurality of spaces formed in between an insert and a substrate by arranging the insert to contact the substrate; and determining the penetration depth of the precursor(s) in the formed spaces.

[0035] A computer program according to the present disclosure comprises computer executable program code which when executed by a processor enables: measurement of the penetration depth of thin film formed following one or more process recipe(s) in the formed spaces; means to extract multiple conformality results.

[0036] According to certain embodiments of the present disclosure, the computer program is configured for interpretation by a user of the multiple conformality results to enable optimisation of process recipes.

[0037] Use of the computer program according to the present disclosure is embodied in process control, process recipe optmisation and / or analysis of HAR-structures. According to an embodiment, the use is in accordance with the embodied method according to the present disclosure as embodied. The use according to certain embodiments of the present disclosure in a process has one or more process parts of the following: involves one or more of Atomic Layer Deposition ALD, MLD (Molecular Layer Deposition), plasma-assisted ALD, PEALD (Plasma Enhanced Atomic Layer Deposition) and photon-assisted or photon-enhanced Atomic Layer Deposition (flash enhanced ALD or photo-ALD), CVD and Atomic Layer Etching (ALE).

[0038] According to the present disclosure of embodiments, an insert can be used, especially in determining HAR-structures and the quality thereof. According to an embodiment, a substrate is mountable on to an insert on a substrate holder, which so facilitates the quality of the coating, including the high aspect ratio structures.

[0039] According to certain embodiments, a HAR-patterned surface is formed on a surface of the substrate holder configured to accommodate a substrate thereon. According to another embodiment, the HAR-patterned surface is formed on an insert provided on the substrate holder and / or integrated into the substrate holder. The insert can be provided as a HAR- patterned plate or disk integrated to the holder, so that a wafer can be set on top of it. In certain embodiments, the HAR-patterned surface is formed on a substrate, including but not limited to a blank wafer or a substrate with a three-dimensional structure, more preferably on the backside of the substrate. According to an embodiment of the present disclosure, alternatively in suitable part, the surface features of the HAR are arranged into a pattern, wherein the pattern is a 3D pattern comprising profiles and recesses, respectively.

[0040] Although a single process recipe (also referred to as a process “run”) as such yields a single result for conformality, the method according to the present disclosure allows running multiple recipes on a single substrate (such as a wafer) and measuring the conformality from each of those recipes.

[0041] Accordingly, the embodied method is clearly far more efficient, as a single deposition series which includes multiple process recipes (“recipes”), can be performed (referred to as the “HAR test”) and the results analysed within a day, for example, instead of the time scale of the previous methods that would have taken several days for nearly the same. According to the present disclosure this is achieved by providing a substrate holder with a surface comprising a number of surface profile structures arranged into a pattern, said structures preferably configured as HAR-structures. In an embodiment, the patterned surface is established by providing an insert comprising said HAR-structures which is arranged on the substrate holder, respectively. In certain embodiments, the HAR-patterned surface is formed on a substrate. According to the first aspect of the present disclosure of the embodiments, a HAR-patterned substrate holder is located in a reaction chamber of an embodied tool and, for example, a number of (for example three) different recipes are run in the embodied tool according to a second aspect of the present disclosure of the embodiments directed to an embodied tool to be used in the embodied method. According to an example about the embodiments, in an embodiment the method can use as the precursor A with pulse lengths as an example. Recipes accordingly have an ensemble of pulse lengths of 0.5s, 1.0s and 1.5s, as an example.

[0042] Such run yields a staircase structure inside a HAR structure, instead of a single step profile. According to an embodiment, each of the steps in the staircase correspond to a set of parameters.

[0043] According to certain embodiments, a macroscopic HAR test structure is integrated to an ALD chamber to form a HAR-system according to the present disclosure of the embodiments. Such an embodied HAR-system transforms a wafer holder, a part of a single function into a multifunction part. As a benefit, accordingly unwanted backside growth can be turned into usefulness so that conformality of the ALD process can be easily determined.

[0044] By the term “backside” we refer to that side (hereby, surface) of the substrate, such as a silicon wafer, for example, which contacts the substrate holder disclosed herewith.

[0045] Such an unwanted side product (backside growth) of an ALD is turned by the embodiments of the present disclosure into a useful use by data acquisition means and further to the analysing software to be used in the process evaluation and / or control.

[0046] Previously, to collect this type of data one had to dedicate resources, to procure special test chips and use tool time. With the embodiments of the present disclosure of the embodiments, the data is passively generated each time a deposition is made. Integrating such a design facilitates to utilize wasted space on a wafer and precursor to useful information directly to the hardware of the chamber, and for analysis by software utilizing the measurement data.

[0047] With the embodiments of the present disclosure of the invention, the data is passively generated each time a deposition is made.

[0048] Accordingly the present disclosure of the embodiments:

[0049] - Facilitates a transformation of a standard part with previously no other function than mere support of a sample, to a powerful test structure without sacrificing its main function. - Facilitates passive generation of conformality data, which has been previously slow, hard and expensive to obtain, making something that was scarce before, into an abundant supply.

[0050] - Turns otherwise wasted potential (backside of a wafer, excess precursor, etc.) into valuable insight to the ALD process and optimization of the process recipes for a specific substrate.

[0051] Such a tool according to a second aspect of the present disclosure is embodied as a HAR test wafer holder, which can even be integrated to a chamber or a part thereof for the HAR tests.

[0052] According to a third aspect of the present disclosure of the embodiments, a method to analyse the distance between the HAR structure opening and the point along the HAR patterned formed space (of which there can be a plurality) where the film thickness has halved relative to that at the structure opening (i.e. penetration depth) is described. This enables interpretation of the highest aspect ratio that each pulse can coat. Although criterion of halfway has been embodied for the method of the present disclosure, a skilled person in the art can apply another criterion as based on the criterion used in the embodiment, for example one or two thirds. According to an embodiment, a computer program can be used according to the method within the hardware apparatus involved.

[0053] Importantly, the embodied method is not limited only to pulses, but the parameters can be any process parameters as applicable, for instance notably, such or similar as flow, pulses, deposition temperature, process pressure, or parameters unambiguously derivable from these individually or combination, by the process geometry being involved. Even different materials can be deposited in a single run and resulting meaningful data from these processes can be extracted.

[0054] According to the present disclosure of the embodiments, the method can be applied to HAR test structures, such as HAR discs. Accordingly a HAR-disc as a HAR-system can be embodied for a dedicated HAR test in the applicable conditions of ALD process phase, even so that an independence of the orientation can be achieved.

[0055] One benefit is that the embodiments can be applied on wafer heaters, by inverting the etched pattern so that the reaction gasses are introduced through the sides instead of a central opening, which broadens the usefulness of the embodiments.

[0056] Accordingly, the usefulness of the embodiments of the present disclosure can be utilized in process research and development, pharma / medical manufacturing, that of power components, MEMS and also in Augmented Reality (AR), Virtual Reality (VR) and Mixed Reality (MR) applications, without intention to limit the use only to the mentioned examples on usefulness, in addition to the ALD-manufacturing devices and their parts.

[0057] According to a fourth example aspect of the invention there is provided a method for determining penetration depth of thin film process precursor(s), comprising:

[0058] - providing an insert;

[0059] - arranging the insert to contact a substrate to form a plurality of spaces in between the insert and the substrate; and

[0060] -feeding the precursor(s) into the formed spaces to determine the penetration depth of the precursor(s).

[0061] According to certain embodiments the backside of the substrate is observed for the staircase formations followed by the backside growth.

[0062] In certain embodiments, the method comprises: feeding the precursor(s) into the formed spaces in a reaction chamber housing the insert and the substrate, the chamber being provided with an embodied tool according to the present disclosure.

[0063] In certain embodiments, the method comprises: feeding the precursor(s) into the formed spaces by using an atomic layer deposition (ALD) process recipe.

[0064] In certain embodiments, the formed spaces are elongated, confined, and / or closed at their one end. In certain embodiments, the formed spaces are in the form of a tunnel (or cavity).

[0065] In certain embodiment, the spaces have a curved shape. In certain embodiment, the spaces have a bendy shape. In certain embodiment, the spaces have a meandering shape. Accordingly, instead of being for example straight, the spaces may be curvy, and / or bendy, and / or meandering.

[0066] In certain embodiments, the spaces are closed at their one end, which one end is located opposite to the mouth of the space, which mouth is connected to an aperture in the middle of the insert.

[0067] In certain embodiments, the formed spaces are elongated spaces open at their one end, closed at their other end, and confined by the substrate and / or the insert along their width, the spaces preferably forming high aspect ratio structures. In certain embodiments, the formed spaces are co-centric elongated cavities.

[0068] In certain embodiments, the insert comprises grooves, which grooves are configured to form said spaces in between the insert and the substrate when the insert and the substrate are in contact with each other.

[0069] In certain embodiments, the spaces have varying widths or varying heights.

[0070] In certain embodiments, the spaces have same lengths (depths). In certain embodiments, the flow area of the spaces is rectangular. In certain embodiments, the width of each of the spaces is equal but the height of the spaces varies. In certain embodiments, the height of each individual space is constant, but the width of the spaces varies.

[0071] In certain embodiments, the spaces are separate from each other, preventing the precursor(s) from flowing from one space directly into an adjacent space.

[0072] In certain embodiments, the insert is disk shaped and / or the shape of the insert is symmetrical around its centre.

[0073] In certain embodiments, the insert comprises an aperture in the centre of the insert, and the aperture is connected to the spaces to allow precursor feed into the spaces through the aperture of the insert. In certain embodiments, the aperture is symmetrically positioned in the centre of the insert. In certain embodiments, this enables each entry hole of the formed spaces to see similar flow geometry or similar flow conditions of the precursor(s). In certain embodiments, the precursor flow into the aperture is from the top. In certain embodiments, the precursor flow into the aperture is from the sides.

[0074] In certain embodiments, the precursor(s) enter the spaces via diffusion. In certain embodiments, the precursor(s) flow within the spaces via diffusion.

[0075] In certain embodiments, the insert and the substrate are horizontally oriented, the insert resting on top of the substrate.

[0076] In certain embodiments, the method comprises: determining the penetration depth by measuring a thin film coating formed on the substrate, at the backside of the substrate.

[0077] In certain embodiments, the method comprises: obtaining results from the measurement of the thin film formed on the substrate backside and adjusting the thin film process according to the obtained results.

[0078] In certain embodiments, the measuring comprises analysis of precursor penetration depth via ellipsometry characterization or quantitative visual inspection, from the backside of the substrate.

[0079] In certain embodiments, results from the measurement of the thin film formed on the substrate are provided to an operator. In certain embodiments said measurements are manually determined by an operator. In certain embodiments, an associated apparatus comprises at least one processor, and at least one memory including a computer program (or computer program code), wherein the at least one memory and the computer program (code) are configured, with the at least one processor, to provide the operator with results from the measurement of the thin film formed on the substrate. The associated apparatus may be a data processing device, or a computer. Said data processing device or computer may be implemented as a partof a deposition reactor process control system, or separately. Herein, the deposition reactor is considered as a deposition reactor, for example an ALD reactor, comprising the reaction chamber. According to such an embodiment variant, the reaction chamber of the reactor belongs to a HAR-system as embodied.

[0080] In certain embodiments, data visualization is provided to the operator. In certain embodiments, appropriate process descriptive parameter(s) and data visualization are provided to the operator. In certain embodiments, input data for the computer program and / or a related data analysis is obtained by the aforementioned embodied method(s) functioning in the HAR-system as embodied according to the present disclosure.

[0081] In certain embodiments, the measuring of the precursor penetration depth is performed from the aperture towards the ends of the spaces, and / or at the backside substrate.

[0082] In certain embodiments, the substrate is a planar substrate, for example a wafer, such as a semiconductor wafer, for example a silicon wafer.

[0083] In certain embodiments, said determining the penetration depth is achieved by measuring a thin film coating formed on the substrate comprises analyzing obtained measurement data (which may be received from a measurement device) optionally by at least one processor; and providing an operator with measurement results based on the analysis. According to a fourth example aspect of the invention there is provided an insert configured to contact a substrate to form a plurality of spaces in between the insert and the substrate for determining penetration depths of thin film process precursor(s) with the method of the example aspects or any of its embodiments.

[0084] Accordingly, in the fourth example aspect there is provided an insert configured to be used in the method of the example aspects or any of its embodiments.

[0085] In certain embodiments, the insert comprises grooves configured to form said spaces when the insert and the substrate contact each other.

[0086] According to a fifth example aspect of the invention there is provided an apparatus comprising at least one processor, and at least one memory including computer program code (or a computer program as a software), wherein the at least one memory and the computer program code (or computer program, i.e. the software) are configured, with the at least one processor, to cause the apparatus to perform:

[0087] - feeding of precursor(s) into a plurality of spaces formed in between an insert and a substrate by arranging the insert to contact the substrate; and

[0088] - determining the penetration depth of the precursor(s) in the formed spaces.

[0089] According to a sixth example aspect of the invention there is provided a computer program comprising computer executable program code which when executed by a processor causes an apparatus to perform:

[0090] - feeding of precursor(s) into a plurality of spaces formed in between an insert and a substrate by arranging the insert to contact the substrate; and

[0091] - determining the penetration depth and the precursor reactivity of the process in the formed spaces.

[0092] According to an embodiment of the present disclosure, an analysis software can be embodied, in connection to the process control software or as a separate software code from the process control, to make analysis by the software code that analyses the penetration depth data to arrive at the data for interpretation of the optimal process parameters for the specific 3D substrate. Precursor reactivity of the process in the formed spaces can be determined.

[0093] According to a seventh example aspect of the invention there is provided an apparatus configured to perform a thin film deposition process and comprising the insert of the fourth example aspect or any of its embodiments. According to an eighth example aspect of the invention, an embodied software is used in process control.

[0094] In certain use-oriented embodiments of the software, the use in process control is targeted to a process that has one or more process parts of the following: Atomic Layer Deposition ALD, MLD (Molecular Layer Deposition), plasma-assisted ALD, PEALD (Plasma Enhanced Atomic Layer Deposition) and photon-assisted or photon-enhanced Atomic Layer Deposition (flash enhanced ALD or photo-ALD), CVD, and Atomic Layer Etch (ALE).

[0095] In certain embodiments, the insert is formed from a polymer and a rigid material. In certain embodiments, the rigid material comprises metal or ceramic material.

[0096] Different non-binding example aspects and embodiments have been illustrated in the foregoing. The embodiments in the foregoing are used merely to explain selected aspects or steps that may be utilized in different implementations. Some embodiments may be presented only with reference to certain example aspects. It should be appreciated that corresponding embodiments may apply to other example aspects as well.

[0097] BRIEF DESCRIPTION OF THE FIGURES

[0098] Some example embodiments will be described with reference to the accompanying figures, in which:

[0099] Figs. 1 A and 1 B show flow charts of a method according to example embodiments;

[0100] Fig. 2a schematically shows an insert according to an example embodiment;

[0101] Fig. 2b schematically shows an insert according to another example embodiment;

[0102] Fig. 3a schematically shows an insert according to yet another example embodiment;

[0103] Fig. 3b schematically shows an insert according to yet another example embodiment;

[0104] Fig. 3c schematically shows an insert according to yet another example embodiment;

[0105] Fig. 4a schematically shows a location of a cross-section of the insert;

[0106] Fig. 4b schematically shows the cross-section taken at the location shown in Fig. 4a;

[0107] Fig. 5a schematically shows a further location of another cross-section of the insert;

[0108] Fig. 5b schematically shows the cross-section taken at the location shown in Fig. 5a;

[0109] Fig. 5c schematically shows a magnified view of an edge of the insert according to an example embodiment;

[0110] Fig. 6a schematically shows a side view of a substrate holder according to an example embodiment;

[0111] Fig. 6b schematically shows a magnified view of an edge of the substrate holder according to an example embodiment; Fig. 6c schematically shows a substrate holder from above according to an example embodiment;

[0112] Fig. 7 illustrate an example of an embodiment of the present disclosure,

[0113] Fig. 7a schematically shows the insert, the substrate and the substrate holder according to an example embodiment;

[0114] Fig. 7b schematically shows the insert, the substrate and the substrate holder including the feed of the precursor according to an example embodiment;

[0115] Fig. 7c schematically shows a flow path of the precursor according to an example embodiment;

[0116] Fig. 8 schematically shows a magnified view of the insert, the substrate and the substrate holder edges;

[0117] Fig. 9a schematically shows the substrate after the precursor deposition according to an example embodiment;

[0118] Fig. 9b shows a visualization of penetration depth analysis results in certain embodiments;

[0119] Fig. 10 shows a process control system in accordance with certain embodiments;

[0120] Fig. 10A illustrates data acquisition from the process by measurements according to the present disclosure of the embodiments;

[0121] Fig. 10B illustrates an embodied computer program product utilizing the measurement data for visualization of penetration depth analysis;

[0122] Fig. 11 schematically shows an apparatus according to an example embodiment;

[0123] Fig. 12A, 12B and 12C illustrate a sample holder as such according to an embodiment from top view (12C) and diagonally aspects (12A, 12B);

[0124] Fig. 13 illustrates an HAR disk, from a flip side view;

[0125] Fig. 14 illustrates an example of a HAR holder superior as side projection for 200 mm wafer example on it, according to an embodiment of the present disclosure;

[0126] Fig.15 illustrates the Fig. 14 embodiment in diagonal perspective 3D view, with indication of a wafer placement orientation;

[0127] Fig 16A and 16B illustrate comparison between an original and flipped geometry as a thickness of function distance from tunnel edge (Fig. 16A) and step coverage as a function of the distance (mm) (Fig 16B), respectively;

[0128] Fig. 17 illustrates an example of a HAR holder superior as side projection for 300 mm wafer example on it, according to an embodiment of the present disclosure;

[0129] Fig. 18 illustrates a wafer holder from a top view, with indication of a loading direction;

[0130] Fig. 19 illustrates a HAR wafer heater, with potential for invert pattern with Fig. 13 and

[0131] Fig. 18 embodiments, and Figs 20A, 20B, 20C illustrates HAR analysis results obtained by the software, according to the present disclosure.

[0132] Fig. 21 illustrates a schematic example on an embodied apparatus with measurement facility according to the present disclosure..

[0133] DETAILED DESCRIPTION

[0134] In the following description, Atomic Layer Deposition (ALD) technology are used as an example. However, Molecular Layer Deposition (MLD) technology can have similar usefulness and can be used as a parallel example of the process for the embodiments of the present disclosure of the ALD, as a skilled person in the art knows from the embodiments, as well as realizes that a number of variants thereof can utilize the embodiments of the present disclosure.

[0135] The basics of an ALD growth mechanism are known to a skilled person. ALD is a special chemical deposition method based on sequential introduction of at least two reactive precursor species to at least one substrate. A basic ALD deposition cycle consists of four sequential steps: pulse A, purge A, pulse B and purge B. Pulse A consists of a first precursor vapor and pulse B of another precursor vapor. Inactive gas and a vacuum pump are typically used for purging gaseous reaction by-products and the residual reactant molecules from the reaction space during purge A and purge B. A deposition sequence comprises at least one deposition cycle. Deposition cycles are repeated until the deposition sequence has produced a thin film or coating of desired thickness. Deposition cycles can also be either simpler or more complex. For example, the cycles can include three or more reactant vapor pulses separated by purging steps, or certain purge steps can be omitted. Or, as for plasma- assisted ALD, for example PEALD (plasma-enhanced atomic layer deposition), or for photon-assisted ALD, one or more of the deposition steps can be assisted by providing required additional energy for surface reactions through plasma or photon in-feed, respectively. Or one of the reactive precursors can be substituted by energy, leading to single precursor ALD processes. Accordingly, the pulse and purge sequence may be different depending on each particular case. The deposition cycles form a timed deposition sequence that is controlled by a logic unit or a microprocessor. Thin films grown by ALD are dense, pinhole free and have uniform thickness.

[0136] As for substrate processing steps, the at least one substrate is typically exposed to temporally separated precursor pulses in a reaction vessel (or chamber) to deposit material on the substrate surfaces by sequential self-saturating (or self-limiting) surface reactions. In the context of this application, the term ALD comprises all applicable ALD based techniques and any equivalent or closely related technologies, such as, for example the following ALD sub-types (sub-types of ALD): MLD (Molecular Layer Deposition), plasma- assisted ALD, for example PEALD (Plasma Enhanced Atomic Layer Deposition) and photon-assisted or photon-enhanced Atomic Layer Deposition (known also as flash enhanced ALD or photo-ALD).

[0137] However, the invention is not limited to mere ALD technology as such, but it can be exploited in a wide variety of substrate processing methods, for example, in Chemical Vapor Deposition (CVD) and other thin film depositions. According to one embodiment of the present disclosure, the analysis software can be applied to material removal by etching, i.e. according to Atomic Layer Etching (ALE).

[0138] In context of ALD techniques, the self-limiting surface reaction means that the surface reactions on the reactive layer of the surface will stop and self-saturate when the surface reactive sites are entirely depleted.

[0139] Fig 1A. presents a flow chart of a method for determining penetration depth of a thin film process precursor, comprising providing an insert (10), arranging the insert to contact a substrate to form a plurality of spaces in between the insert and the substrate (20), and feeding the precursor into the formed spaces (30) to determine the penetration depth of the precursor. According to an alternative embodiment, the method comprises determining the penetration depth (40) by measuring the thin film coating formed on the substrate at this point.

[0140] As illustrated in Fig 1 B, the method can alternatively comprise providing a substrate holder, being used, with a tunnel structures 10. Accordingly a wafer can be placed on such substrate holder that has a plurality of spaces in between the wafer and the substrate holder 20. Thin film process precursor(s) are fed into the formed spaces 30. The penetration depth is determined 40.

[0141] In certain embodiments, the insert and the substrate are housed by a reaction chamber of a deposition reactor, such as an ALD apparatus (or an ALD reactor). According to an embodiment of the present disclosure, the penetration depth (40) is determined, and in a variant of an embodiment from the backside of the substrate to which the film is deposited, or an insert, or from a wafer, for example.

[0142] Fig. 2a presents an example of an insert 100. In particular, Fig. 2a shows a bottom view of the insert 100, wherein the insert 100 in this example is in the general shape of a disk. The insert 100 comprises two grooves in its bottom surface. The insert 100 further comprises an aperture (through hole) 110 in the centre of the insert 100. The grooves have entry openings in a wall surrounding the aperture 110. The grooves are configured to form spaces 101 in between the insert 100 and a substrate, such as a wafer, when the insert 100 is applied to contact the substrate. In the context of the present description, each space 101 has a width, a height, and a depth (length). The width w of the space 101 is the dimension of the space 101 visible from the bottom, which is perpendicular to the direction of the radius of the insert 100. The length I of the space 101 is the dimension of the space 101 that is parallel to the direction of the radius of the insert 100, when observing the insert from the bottom. The height h of the space 101 is the remaining dimension of the insert 100 perpendicular to both w and I.

[0143] According to an embodiment, as shown in Fig. 2a, the spaces 101 have varying widths w. According to this embodiment, the other dimensions (respective heights and respective lengths) of each space 101 are equal.

[0144] Fig. 2b presents an example of an insert 100 comprising four grooves, which grooves are configured to form spaces 101 in between the insert 100 and a substrate when the insert 100 is applied to contact the substrate. According to an embodiment, the spaces 101 have varying widths. The other dimensions (respective heights and respective lengths) of each space 101 are equal.

[0145] Fig. 3a presents an example of an insert 100 comprising eight grooves, which grooves are configured to form spaces 101 in between the insert 100 and a substrate when the insert

[0146] 100 is applied to contact the substrate. According to this particular embodiment, the spaces

[0147] 101 have varying heights. The other dimensions (respective widths and respective lengths) of each space 101 are equal.

[0148] Fig. 3b presents an example of an insert 100 comprising twelve grooves, which grooves are configured to form spaces 101 in between the insert 100 and a substrate when the insert

[0149] 100 is applied to contact the substrate. According to this particular embodiment, the spaces

[0150] 101 have varying heights. The other dimensions (respective widths and respective lengths) of each space 101 are equal.

[0151] Fig. 3c presents an example of an insert 100 comprising bendy grooves, which grooves are configured to form spaces 101 in between the insert 100 and a substrate when the insert 100 is applied to contact with the substrate. The bendy shape of the grooves allows the spaces 101 to be longer than straight spaces 101. According to this particular embodiment, the spaces 101 have varying heights. The other dimensions (respective widths and respective lengths) of each space 101 are equal.

[0152] According to certain embodiments, a plurality of spaces 101 form in between the insert 100 and the substrate 200 when applying the insert 100 to contact a substrate (or substrate surface). In certain embodiments, the number of the spaces 101 is at least two.

[0153] As presented in the foregoing with reference to Figs. 2a, 2b, 3a and 3b, the insert 100 comprises the aperture 110 in the centre of the insert 100. The aperture 110 is in flowcommunication with the spaces 101 to allow the precursor to be fed to the spaces 101 through the aperture 110 of the insert 100. According to an embodiment, the precursor enters the spaces 101 and flows within the spaces 101 via diffusion. As presented in Figs. 2a, 2b, 3a and 3b, the insert 100 is disk shaped and / or the shape of the insert 100 is symmetrical around its centre.

[0154] In certain embodiments, the spaces 101 are elongated, confined, and / or closed at their one end. In certain embodiments, the spaces 101 are closed at their one end located opposite to the mouth of the space 101 (the mouth of the space 101 being in the wall of the aperture 110). The spaces 101 have varying widths or varying heights depending on the embodiment. In certain embodiments, the spaces 101 have same lengths.

[0155] Fig. 4a presents a location of a cross-section of the insert 100 of Fig. 3a. The cross-section is marked with a dashed line. The cross-section cuts the grooves that form the spaces 101 together with the substrate.

[0156] Fig. 4b presents the cross-section of the insert 100 according to the cross-section line marked in Fig. 4a. In this embodiment, the spaces 101 have varying heights hi and h2. In certain embodiments, as shown in Fig. 4b, the heights hi and h2 are constant. According to other embodiment, the spaces 101 have radially decreasing heights.

[0157] Different dimensions of the spaces 101 allow the precursor to travel varying distances in the individual spaces 101. In wider or higher spaces 101 , the precursor penetrates deeper than in narrow or shallow spaces 101 . The thin film process variables such as processing pressure, precursor pulse duration and duration between the precursor pulses have an effect on the precursor penetration depth. Thus, by varying the thin film process variables, the precursor penetrates different depths in the spaces 101. The height dimension is exaggerated in Fig. 4b for an illustrative purpose. In certain embodiments, the insert 100 is composed of a composite material of a polymer and a rigid material. The polymer material is preferably relatively soft and heat resistant, such as polymethyl methacrylate (PMMA), polydimethylsiloxane (PDMS), polytetrafluoroethylene (PTFE) or alike. The rigid material is preferably a metal or ceramic plate. In this example embodiment, the grooves of the insert 100 that form spaces 101 , when the insert is applied to contact a substrate, are imprinted on the polymer material and the rigid material is included to the insert 100 to maintain the form of the polymer and to ease handling. An achieved additional technical effect is improved compensation of the change of shape due to thermal expansion via the polymer material.

[0158] Fig. 5a presents a location of a further cross-section of the insert 100 of Fig. 3a. The crosssection is marked with a dashed line. The cross-section cuts the insert 100 at an area in between the grooves that form the spaces 101 .

[0159] Fig. 5b presents the cross-section of the insert 100 according to the cross-section line marked in Fig. 5a. The insert 100 has a diameter d1. The insert 100 has a body that has even thickness in the areas that do not form the spaces 101. Thus, the spaces 101 are separate from each other, preventing the precursor flow from one space 101 to adjacent spaces 101.

[0160] Fig. 5c presents schematically a magnified view of an edge of the insert 100. In certain embodiments, the edge of the insert 100 has a horizontally extending protrusion 120. The protrusion 120 allows the insert to be moved, lifted and lowered. In certain embodiments, the protrusion 120 is positioned at an upper corner of the edge of the insert 100. The diameter d1 represents an outer diameter of the insert 100 from edge to edge at an area of the edge lacking the protrusions 120.

[0161] According to an optional embodiment, the insert 100 has a vertical protrusion (a notch) 130 protruding from the outer edge of the bottom of the insert 100. The protrusion 130 allows the insert 100 and the substrate 200 to be centered. The protrusion 130 is a guide in alignment of the insert 100 and the substrate 200.

[0162] Fig. 6a presents a cross-section of a substrate holder 300 according to certain embodiments. In certain embodiments, a top surface of the substrate holder 300 has the shape of a round plate. In certain embodiments, the round plate receives the insert and a substrate, and the insert is positioned onto the substrate holder 300 prior the in-feed of the precursor(s). The substrate holder 300 has an inner diameter d2 and an outer diameter d3. Fig. 6b presents schematically a magnified view of an edge of the substrate holder 300. The edge of the substate holder 300 has a protrusion 310. The protrusion 310 allows the insert to be moved, lifted and lowered. The protrusion 310 allows the substrate to be placed on top of the inset in the substrate holder 300. The protrusion 310 prevents the substrate from sliding or moving on top of the substrate holder 300. Accordingly the insert on the substrate holder can have a similar formation.

[0163] Fig. 6c shows the substrate holder 300 from above. The protrusion 310 is visible from above and the protrusion 310 goes around a circular edge of the substrate holder 300. The inner diameter d2 of the substrate holder 300 is smaller than the outer diameter d3 of the substrate holder 300. In certain embodiments, the substrate holder 300 has an indent 320, or at least two indents 320 as shown in Fig. 6c. The said indents 320 allow a loading tool or a tool operator to grip the substrate, and when the insert has also the same formations, at the matching location, the substrate can be handled leaving the insert integrated to the substrate holder.

[0164] Fig. 7a presents the insert 100, the substrate 200 and the substrate holder 300 as a side view. The substrate 200 is placed on top of the substrate holder 300. The diameter d1 of the insert 100 is smaller than the inner diameter d2 of the substrate holder 300 but just larger than the diameter of the substrate 200. The insert 100 is placed on top of the substrate 200. The substrate 200 and the insert 100 are in contact to form the plurality of spaces 101 in between the insert 100 and the substrate 200. According to an embodiment, when the insert 100 and the substrate 200 are horizontally oriented, the insert 100 is (or rests) on top of the substrate 200. In certain embodiments, a bottom side of the insert 100 is in contact with a top side of the substrate 200 except in positions in which the aperture 110 and the spaces 101 are located (and at the location of the optional protrusion (notch) 130 that merely surrounds the substrate 200).

[0165] Fig. 7b presents the insert 100, the substrate 200 and the substrate holder 300 including the feed of the precursor(s). The feeding of the precursor(s) occurs through the aperture 110 in the centre of the insert 100.

[0166] Fig. 7c presents a flow path of the precursor. As mentioned, the feeding of the precursor(s) occurs through an aperture 110 in the centre of the insert 100. The aperture 110 is in flowcommunication with the formed spaces (or high aspect ratio structures) 101 to allow the precursor(s) to enter the spaces 101 through the aperture 110 of the insert 100. The precursor(s) flows first downwards through the aperture 110, and when it approaches the substrate 200 surface, the precursor flow turns and flows horizontally along the substrate 200 surface into the spaces 101. According to an embodiment, the precursor(s) enters the spaces 101 via diffusion. The spaces 101 have varying widths or varying heights. In certain embodiments, the spaces 101 have same lengths. Therefore, the precursor flow penetrates the spaces 101 varying depths. Whilst penetrating the spaces 101 , the precursor(s) forms a thin film on the substrate 200 surface. After the precursor flow has reached its maximum penetration depth, the remaining precursor(s) and reaction by-products (if any) flow back through the aperture 110. Then, they flow along the surface of the insert 100 and over the edge of the insert 100, after which they exit the reaction space and are removed via an exhaust line (not shown).

[0167] Fig. 7d presents the insert 100, the substrate 200 and the substrate holder 300 as a side view. The substrate 200 is placed on top of the insert further on the substrate holder 300. The diameter d1 of the insert 100 is smaller than the inner diameter d2 of the substrate holder 300 but just larger than the diameter of the substrate 200. The insert 100 is placed under the substrate 200, on the substrate holder. The substrate 200 and the insert 100 are in contact to form the plurality of spaces 101 in between the insert 100 and the substrate 200. According to an embodiment, when the insert 100 and the substrate 200 are horizontally oriented, the substrate 200 is (or rests) on top of the insert 100. In certain embodiments, a top side of the insert 100 is in contact with a bottom side of the substrate 200 except in positions in which the aperture 110 and the spaces 101 are located (and at the location of the optional protrusion (notch) 130 that merely surrounds the substrate 200). The precursors can have access to the substrate surface via the substrate holder 300 openings 110A and / or insert openings 110 (c.f. Fig. 14 example, too). In certain embodiments the insert is integrated into the substrate holder.

[0168] Fig. 7e presents the insert 100, the substrate 200 and the substrate holder 300 including the feed of the precursor(s) on to the substrate. The precursors can have access to the substrate surface via the substrate holder 300 openings 110A and / or insert openings 110 (c.f. Fig. 7g, 14 example, too).

[0169] Fig. 7f presents a flow path of the precursor. As mentioned, the feeding of the precursor(s) occurs through an aperture 110 in the centre of the insert 100. The reference 110A is illustrating an aperture or opening through the substrate holder 300. The apertures 110 and 110A are in flow-communication with the formed spaces (or high aspect ratio structures) 101 to allow the precursor(s) to enter the spaces 101 through the apertures 110 and 110A of the insert 100. In the situation of the example, the spaces 101 can be both sides of the substrate 200, according to an embodiment variant even independently from each other shaped and / or dimensioned. According to an embodiment variant, the downside insert part can be patterned formed on a heater. The precursor(s) flows first downwards through the aperture 110, and when it approaches the substrate 200 surface, the precursor flow turns and flows horizontally along the substrate 200 surface into the spaces 101 . Part of the flow is guided to the down side of the substrate 200 surface. According to an embodiment, the precursor(s) enters the spaces 101 via diffusion. The spaces 101 have varying widths or varying heights, which is also illustrated by the way of drawing. In certain embodiments, the spaces 101 have same lengths. Therefore, the precursor flow penetrates the spaces 101 varying depths. Whilst penetrating the spaces 101 , the precursor(s) forms a thin film on the substrate 200 surfaces, of which the downside substrate surface may even belong to another separate substrate at the upper side of the substrate 200 (i.e. as stacked), both being potentially addressed to their dedicated use-applications according to the precursor originating film penetration depths. After the precursor flow has reached its maximum penetration depth, the remaining precursor(s) and reaction by-products (if any) flow back through the aperture 110. Then, they flow along the surface of the insert 100 and over the edge of the insert 100, after which they exit the reaction space and are removed via an exhaust line (not shown).

[0170] Fig 7g illustrates an embodiment according to the present disclosure. The substrate 200 has been placed on an insert 100 for holding the substrate in reaction chamber, so that the precursor(s) can reach the back side (i.e. down side in the Fig 7g) of the substrate 200. In an embodiment, the insert is integrated to a substrate holder.

[0171] Fig. 8 presents a magnified view of the insert 100, the substrate 200 and the substrate holder 300 edges as a side view. The protrusion 130 allows the insert 100 and the substrate 200 to be centered with respect to substrate holder 300, and by formation 131 to each other. The protrusion 130 is a guide in alignment of the insert 100 and the substrate 200. According to an embodiment, the method comprises obtaining results from the measurement of the thin film formed on the substrate and adjusting the thin film process according to the obtained results. According to an embodiment, the measuring comprises analysis of precursor penetration depth via quantitative visual inspection, or ellipsometry characterization, or other suitable characterization technique according to the measurements performed by the apparatus (c.f. Figs 10, 10A and 11 ). The ellipsometry characterization or other suitable characterization technique is performed via a suitable measurement apparatus (or device). In certain embodiments, the measuring of the precursor penetration depth is performed from the aperture 110 towards the ends of the spaces 110. According to an embodiment of the present disclosure, the precursor penetration depth is measured from the backside of the substrate. According to an embodiment a software tool is used, in determination of the penetration depth, especially in certain embodiments for HAR-structures.

[0172] Monitoring and process control of the thin film deposition occurs by quantifying the penetration depth of the thin film deposition. Fig. 9a shows the substrate 200 after the precursor deposition. According to an embodiment, it can be determined with a naked eye, through quantitative visual inspection, how the thin film deposition has formed thin film into the spaces 101 (and onto the underlying substrate 200). The thin film deposition can form an image 210 on the substrate 200, in which it can be observed visually how the penetration depths vary between the spaces 101 with varying widths or heights.

[0173] The quantitative visual inspection may comprise comparing the formed thin film image 210 to a glass disk, which has a scale written. In this case, the visual inspection comprises comparing the formed image 210 to the scales on the glass disk. The operator is able to take a note of the readings that the scales on the glass disk present and compare those readings to the known values of the optimal operating conditions. By comparing the scale readings, the operator is able note if the process conditions at the time of the monitoring are not optimal. According to an embodiment variant, the operator is a software entity as a part of an embodied program code, to perform the analysis about the material thicknesses.

[0174] In a processing facility, there may be provided a model substrate with an ideal image representing ideal process conditions for process monitoring purposes. The model substrate can be obtained by coating a substrate according to the disclosed method in found optimal operating conditions to produce the ideal image. For the purpose of process control and / or monitoring, an operator may perform the disclosed method later with the existing process conditions to form a “monitor substrate” (or a substrate with an image during monitoring). After that, the operator can compare visually the monitor substrate with the model substrate. The operator is able to note if the process conditions at the time of the monitoring are not optimal. The operator then can adjust the process variables accordingly to improve the process quality. According to an embodied software tool, that is made much faster than by a human operator.

[0175] The ellipsometry characterization comprises characterization of the penetration depth of the precursor(s). In an embodiment, the ellipsometry characterization may comprise further characterization of the thickness profile of the thin film. A computer program may be used to aid a human operator, or can be the operator in data analysis and visualization of the ellipsometry characterization for higher efficiency and repeatability. Fig. 9b shows a visualization of penetration depth analysis results in certain embodiments. The visualization labels a number of tunnels with different tunnel heights and shows penetration depths in the tunnels as well as the thickness of thin film coating formed on the substrate.

[0176] Fig. 10 shows a block diagram of a computerized process control system of a deposition apparatus or reactor in accordance with certain example embodiments. The control system 750 comprises at least one processor 751 to control the operation of the apparatus and at least one memory 752 comprising a computer program or software 753. The software 753 includes instructions or a program code to be executed by the at least one processor 751 to control the apparatus. The software 753 may typically comprise an operating system and different applications. The control system 750 may be configured as a computerized system, which uses one or more computers.

[0177] The at least one memory 751 may form part of the apparatus or it may comprise an attachable module. The control system 750 further comprises at least one communication unit 754. The communication unit 754 provides for an interface for internal communication of the measurement apparatus. In certain embodiments, the control unit 750 uses the communication unit 754 to send instructions or commands to and to receive data from different parts of the apparatus, for example, measuring and control devices, valves, and other adjustment devices (not shown).

[0178] The control system 750 may further comprise a user interface 756 to co-operate with an operator, for example, to receive input such as process parameters from the operator. In certain embodiments, the user interface 756 is connected to the at least one processor 751 .

[0179] As to the operation of the apparatus, the control system 750 controls e.g. the in-feed of precursor vapor into the plurality of spaces formed in between the insert 100 and the substrate 200 for determining the penetration depth.

[0180] In certain embodiments, the control system 750 comprises a measurement device 757 that provides measurement(s), such as ellipsometry characterization measurement for further analysis. In accordance with certain embodiments, the measurement device 757 is configured, by means of being programmed, for example, to perform a measurement sequence to the substrate 200. In accordance with certain embodiments, the measurement device 757 is programmed to collect the results of the measurement(s) (measurement data) performed during the measurement sequence.

[0181] As a part of the control system 750, or separate from the control system 750, a program module can be implemented, which analyses obtained measurement data. In certain embodiments, the program module (or program code) is implemented in said software 753. In accordance with certain embodiments, the at least one processor 751 performs data analysis to the obtained measurement data. In accordance with certain embodiments, measurement data received or obtained from the measurement device 757 are analyzed by the at least one processor 751 to determine the penetration depth, and an operator is provided with measurement results and / or visualization based on the analysis. The measurement results / visualization may be presented at the user interface 156 or at a separate display device.

[0182] Fig. 10A illustrates measurements by an ensemble of sensors to obtain data for the HAR- measurements according to the present disclosure, to be relayed to the software 753, for determination of the penetration depths. Accordingly Fig. 10A illustrates in a schematic way data acquisition by measurements based on a sensor system 757, which can measure process data based on optical quantities 1001 , electric quantities, 1002, chemical quantities 1003 and / or mechanical quantities 1004. The data acquisition also uses HAR-parameters HAR-P that are available at the measurements, and / or iteratively calculated according to the process data history. The dashed line to COMM -marked box is illustrative of use of the measured data according to the embodiment in the present disclosure as illustrated further in Fig. 10. Film thickness can be measured by optical means 1001 as such. The measurement can be based on refractive index, ellipsometry, and / or diffraction in suitable part. The electrical properties describing quantities 1002 can be based on resistivity, resistance of the film, as well as the composition together with the chemical quantities 1003 and / or mechanical quantities 1004, such as the dimensions, flow rates, type of flow, as well as the data about the frictional forces in relation to the diffusion for example. Some HAR-P parameters can comprise information about number of tunnels, the heights and widths thereof.

[0183] Fig. 10B illustrates a part of the software 753, a program code, that is used in processing the measured data, as well as the HAR-P parameters of the process. The software can comprise parts that control the process by the measured parameters, and is capable to select the process cycle involved timings of the valves, and pressures for the precursors as well as purging therebetween. Accordingly the software can calculate the HAR-objects aspect ratios, as based on the geometry, which can be illustrated by the dimensions of the HAR-objects. Such dimensions can be fractal dimensions where applicable, but also may comprise hydraulic diameter, where applicable as well as the depth of the HAR-objects in question.

[0184] The software can also calculate film thickness profiles, along the tunnels individually, and so identify the features of the thickness profiles (c.f. Figs 20A, 20B and 20C). Accordingly also film penetration depth, i.e. the distance from the structure opening till the film growth reduces by 50% ends. Coated aspect ratios can be directly obtained, as well as maximum coated aspect ratio, which can be used for smaller HAR-structures as the lower boundary estimate. Reactant reactivity can be obtained, as based on thickness profile steepness, (c.f. Figs 20A to 20C). Accordingly, the steeper the profile, the higher the reactivity. Can be used in extracting the sticking probability.

[0185] The software can provide analysis for the HAR Growth Constant (HGC), which describes the growth in macroscopic structures and so allows the estimation of conformality for any other macroscopic HAR structures involved in the process so monitored and / or controlled.

[0186] As an option for the analysis of staircase step function is available, i.e. by using selected Penetration Depths (PDs, like 83%, 50% and 17% as in Figure 20C).

[0187] Fig. 11 schematically shows an apparatus 800, such as an ALD reactor or another deposition apparatus, configured to perform the disclosed method in accordance with certain embodiments. The apparatus 800 comprises a reaction chamber 801 that encloses a reaction space 810. The reaction space 810 may be heated. The reaction chamber 801 houses the substrate 200 and the insert 100 in contact with the substrate 200. In certain embodiments, the substrate 200 and the insert 100 are supported by the substrate holder 300. Precursors (A, B) (or precursor vapor) are fed into the reaction chamber 801 through an inlet 802. The precursors (A, B) are fed into the inlet 802 via individual pipelines 803, 804 from individual precursor containers 805, 806. In the event of ALD processing, the precursors (A, B) are fed alternately. After the apparatus 800 has performed the thin film deposition process, the remaining precursors (A, B) exit the reaction chamber 801 via an exhaust line 807. In an embodiment, the in-feed of the two precursors (A, B) is from a top portion of the reaction chamber 801 and the exhaust from the bottom. Fig. 12A, 12B and 12C illustrate a sample holder as such according to an embodiment from top view (12C) and diagonally aspects (12A, 12B). Fig. 13 illustrates an HAR disk, from a flip side view.

[0188] Fig. 14 illustrates an example of a HAR holder called as side projection for 200 mm wafer substrate 200 example, according to an embodiment of the present disclosure. Precursor gas can be delivered to the substrate (backside thereof) via a separate opening 110A provided in the substrate holder (Fig. 14). In such an event, the substrate holder is preferably provided with a backside gas supply being configured to supply precursor gas and / or purge gas through a substrate pedestal module (not shown) to a region defined with spaces 101 below a lower surface of the substrate wafer 200 during deposition.

[0189] Fig. 15 illustrates the Fig. 14 embodiment shown in diagonal perspective 3D view, with indication of a wafer insertion direction,

[0190] Fig 16A and 16B illustrate comparison between the configuration of Fig 7a versus Fig 7d as a thickness of function distance from tunnel edge (Fig. 16A) and step coverage as a function of the distance (mm) (Fig 16B.), respectively.

[0191] Fig. 17 illustrates an example of a HAR-holder as shown as a side projection for 300 mm wafer as a substrate example, according to an embodiment of the present disclosure,

[0192] Fig. 18 illustrates a wafer holder from a top view, loading direction indicated, and Fig. 19 illustrates a HAR -wafer heater, with potential for invert pattern with Fig. 13 and Fig. 18 embodiments.

[0193] Figs 20A, 20B, 20C illustrates HAR analysis results of the software, according to the present disclosure. According to the present disclosure, the embodied HAR analysis software uses for the input raw data from the HAR disk. Such data can comprise, but is not limited only to the examples in the following such as film thickness, refractive index, sheet resistance or other metric along the depth in the tunnel. Optionally or in addition, the nominal thickness (film thickness / metric just outside the HAR structures, in HAR disk the points at the doughnut hole) can be used also. Input can read also some HAR disk parameters, such as Number of tunnels, height & width of the tunnels, without an intention to limit the selection only to the mentioned examples. The embodied software according to the present disclosure can provide as output information Film thickness profiles along each tunnel, which is in general useful, to see the profile. The user can identify characteristic features of the thickness profiles.

[0194] In Fig 20A, examples of processes are shown, where there are thickness profiles that are drastically different. Yellow (left) and green (right) lines are respectively the film penetration depths for 80% and 50% of the nominal thickness. In Fig 20A, there is an illustration that has penetration depth of ~40mm. In Fig. 20B image there are 20mm (80%) and 28mm (50%) penetration depths. Dividing these values with the structure height (0.53mm, for example) will give the coated aspect ratios in the indicated examples.

[0195] The software can provide results for a measurement of the film penetration depth (i.e. the distance from the structure opening till the film growth ends). This is possible for coated aspect ratio, and can be directly calculated from this. Maximum obtained coated aspect ratio can be used for smaller HAR structures as the lower bound. Analysis of reactant reactivity from the thickness profile steepness can be provided. It is also noted that the steeper the profile is, the higher the reactivity. Extracting the sticking probability can be achieved from the data as processed by the software.

[0196] Accordingly one aspect of the analysis by the software is for the HAR Growth Constant (HGC) that describes the growth in macroscopic structures and so allows the estimation of conformality for any other macroscopic HAR structures.

[0197] Optionally or in addition, for the analysis of staircase step functions can be obtained, i.e. using selected PDs (like 83%, 50% and 17% as shown in example in Fig 20C): Fig 20C is illustrating an example of staircase function. Each step corresponds to different pulse length and their PDs and are marked by the horizontal lines. These results can be used to calculate the HGC of a given processes. In this example there were three different steps, each corresponding to three different pulse lengths.

[0198] Fig. 21 illustrates a schematic example on an embodied apparatus with measurement facility and flipping mechanism according to the present disclosure as embodied. The apparatus 810 has a reactor 801 in accordance with the Figs. 10, 10A, 10B and Fig. 11 embodiments. However the Embodiment according to the present disclosure in Fig. 21 have a measurement set-up 757 to provide process parameter characterizing information, as illustrated in the Fig at the right drawn box. According to an embodiment, the apparatus according to the present disclosure 810 has also a flipping tool FLI, for changing the position of the substrate and the insert thereon, so that the backside of the substrate or insert is / are revealed to the measurement set-up 757and the backside growth can be used be in the HAR- measurements. In an embodiment the flipping tool FLI can turn at least one of the items 100, 200, 300 by 180 degrees, and back, when desired, in a operator selectable direction and / or rotational position between 0 and 180 degrees. The flipping can be automated, and integrated into the software controlling the process, and / or making the measurements for the HAR information.

[0199] The foregoing description has provided by way of non-limiting examples of particular implementations and embodiments a full and informative description of the best mode presently contemplated by the inventors for carrying out the invention. It is however clear to a person skilled in the art that the invention is not restricted to details of the embodiments presented in the foregoing, but that it can be implemented in other embodiments using equivalent means or in different combinations of embodiments without deviating from the characteristics of the invention.

[0200] Furthermore, some of the features of the afore-disclosed example embodiments may be used to advantage without the corresponding use of other features. As such, the foregoing description shall be considered as merely illustrative of the principles of the present invention, and not in limitation thereof. Hence, the scope of the invention is only restricted by the appended patent claims.

Claims

CLAIMS1 . A method for determining a penetration depth of a thin film formed following one or more process recipe(s), comprising: obtaining (10) a substrate holder (300) comprising a surface with a number of surface features formed thereon, placing (20) a substrate (200) on the substrate holder (300) such that a plurality of spaces (101 ) is formed in between the substrate (200) and the surface of the substrate holder (300); feeding (30) by running the one or more process recipe(s) in a deposition apparatus (801 ), where precursor(s) are fed (30) into the formed spaces (101 ), and measuring the penetration depth of the formed thin film in the formed spaces (101 ).

2. The method of claim 1 , comprising: feeding (30) the precursor(s) into the formed spaces (101 ) in a reaction chamber (801 ) of the deposition apparatus (800) housing the substrate and the surface of the substrate holder (300).

3. The method of claim 1 or 2, comprising: feeding (30) the precursor(s) into the formed spaces (101 ) by using an atomic layer deposition (ALD) process recipe.

4. The method according to claim 1 , 2 or 3, wherein the method comprises determining (40) the penetration depth of the film formed on a backside of the substrate (200).

5. The method according to anyone of the preceding claims, wherein the plurality of spaces into which the precursors are fed are elongated (I) spaces (101 ), (110) open at their one end, closed at their other end, and confined by the substrate (200) and / or the surface of the substrate holder (300) along their width (w).

6. The method of any preceding claim, wherein the spaces (101 ) have varying widths (w) or varying heights (hi ), (h2).

7. The method of any preceding claim, wherein the spaces (101 ), (110) are separate from each other, preventing the precursor(s) from flowing from one space (101) directly into an adjacent space (101 ).

8. The method of any preceding claim, wherein the substrate holder (300) comprises a central aperture (110), (110A) or a central recess formed in its (300) surface, said aperture or recess being connected to the spaces (101 ) to allow precursor feed into the spaces (101 ) through said aperture (110), (110A) or recess.

9. The method of any preceding claim, wherein said determining comprises: obtaining measurement data of the penetration depth of the thin film into the one or more spaces, analyzing the obtained measurement data by at least one processor (751 ); and providing an operator with measurement results based on the analysis.

10. The method of claim 9 comprising: utilizing the obtained results, including multiple conformality results, from the measurement of the thin film formed on the substrate (200); and adjusting the thin film process according to the obtained results.11 . The method of claim 10 wherein the multiple conformality results enable adjustment of parameters of the thin film process, the parameters selected from the group including: flow, pulses, deposition temperature or process pressure.

12. An insert (100) integrated to a substrate holder (300) configured to contact a substrate (200) to form a plurality of spaces (101 ), (110), (110A) in between the insert (100) and the substrate (200) for determining penetration depths of thin film process precursor(s) by use in the method according to any one of the preceding claims.

13. An apparatus (750), (800) comprising at least one processor (751 ), and at least one memory (752) including a computer program code (753) as a software (SW), wherein the at least one memory (752) and the computer program code (753) are configured, with the at least one processor (751 ), to cause the apparatus (800) to perform in software control (753) of the at least one processor (751 ): under the control system’s (750) control, in-feeding (802), (803), (804) of precursor (A), (B) vapors into the apparatus (810) and therein in its reaction chamber (801 ), into a plurality of spaces formed in between to a substrate holder (300) integrated insert (100) and the substrate (200), as based on a measurement device (757) measured measurement data from a measurement sequence,wherein said plurality of spaces (101 ), (110), (110A) being formed by the contact of said insert (100) and substrate (200); and determining (40) the penetration depth (PD) of the precursor(s) in the formed spaces (101), wherein said apparatus (800) comprises in the reaction chamber (801 ) a substrate holder (300) that comprises a surface with a number of surface features formed thereon configured to place a substrate (200) on to the substrate holder (300) integrated insert (100) with a plurality of therebetween formed spaces (101 ), said spaces (101 ) being in the position between said substrate (200) and the surface of the substrate holder (300) for implementation of a method for determining a penetration depth of a thin film therefrom according to anyone of the previous claims 1 to 11 .

14. A computer program (753), (SW) comprising computer executable program code (SW), which when executed by a processor (751 ) of a control system (750) enables the control system (750) to control the process apparatus (800) of claim 13, via acquisition of measured (MEAS), (757) process data (1001 ), (1002), (1003), (1004), HAR-parameters and / or (HAR-P) by the sensor system (757) for performing a measurement of the penetration depth of a thin film formed following one or more process recipe(s) in the formed spaces (101 ), according to the method in anyone of the claims 1 to 11 ; and extracting by means (SW) multiple conformality results.

15. The computer program (753), (SW) according to claim 14, wherein the computer program (753), (SW), is configured so that for interpretation by a user of the multiple conformality results, enables optimisation of process recipes.

16. Use of the computer program (753), (SW) of claim 15 in process control, process recipe optmisation and / or analysis of HAR-structures.

17. Use according to claim 16, wherein the process involves one or more of Atomic Layer Deposition ALD, MLD (Molecular Layer Deposition), plasma-assisted ALD, PEALD (Plasma Enhanced Atomic Layer Deposition) and photon-assisted or photon-enhanced Atomic Layer Deposition (flash enhanced ALD or photo-ALD), CVD and Atomic Layer Etching (ALE).

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