Chuck system and method with enhanced electrical isolation for substrate-biased ALD

Abstract

The invention relates to a chuck system and method with enhanced electrical isolation for substrate-biased ALD. A chuck system for performing a substrate-biased atomic layer deposition process for forming a conductive film on a substrate includes: a conductive substrate holder configured to support the substrate; and a conductive susceptor that supports the substrate holder. The electrically isolating layer is sandwiched between the substrate holder and the susceptor. The electrically isolating layer has an outer end and an edge recess formed in and extending around the outer edge. The edge recess is configured to prevent the conductive film from coating the entire interior of the edge recess, thereby maintaining electrical isolation between the substrate holder and the susceptor.

Description

[0001] This divisional application is a divisional application based on the Chinese patent application with application number 201880008633.3, application date January 23, 2018, and invention name “Chuck system and method with enhanced electrical isolation for ALD with substrate bias”. Technical Field

[0002] The present disclosure relates to atomic layer deposition (ALD), and more particularly to a chuck system and method with enhanced electrical isolation for ALD with substrate biasing. Background Art

[0003] Atomic layer deposition (ALD) is a thin film deposition technique that sequentially exposes a substrate to a variety of different chemical and / or energy environments to form a thin film on the substrate surface. An overview of the ALD process is presented in George's article entitled "Atomic Layer Deposition: An Overview", Chem. Rev. 2010, 110, pp. 111-113 (published on the Web on November 20, 2009), which is incorporated herein by reference. The ALD process is also described in U.S. Patent No. 7,128,787, which is incorporated herein by reference. Example ALD systems are disclosed in U.S. Patent Application Publication No. US2006 / 0021573, U.S. Patent No. 8,202,575, and PCT Publication No. WO 2015 / 080979, which are incorporated herein by reference.

[0004] A typical ALD process involves supporting a substrate on a chuck within a reaction chamber. The ALD process involves pulling a vacuum in the reaction chamber and then introducing precursor gases, which in the example include a metal. The metal chemically adsorbs with pre-existing chemical moieties on the substrate surface. A purge cycle (e.g., with an inert gas) is then used to remove excess precursor gas and reaction products. A second precursor is then introduced into the reactor, where the second precursor reacts with the chemically adsorbed moieties of the first reactant. A second purge cycle removes excess second precursor gas and reaction products. This process is repeated to slowly build up the film layer by layer on the substrate surface. The ALD process can be controlled to subatomic layer thicknesses.

[0005] The ALD process is highly conformal, meaning that the film closely follows the topography of the substrate surface. This is an important property in many applications such as semiconductor manufacturing, where the substrate can have significant topographic variations, including high aspect ratio trenches.

[0006] The ALD process can be used to deposit different types of conductive films. The deposition process for a given conductive film can be modified by biasing the substrate with an RF voltage, for example by increasing the deposition rate. This biasing is typically performed by using a conductive substrate holder that supports the substrate in the reaction chamber and provides a bias voltage to the substrate holder. The conductive substrate holder needs to be electrically isolated from the body of the chuck, which is grounded along with the reaction chamber. This is achieved using an electrically insulating layer.

[0007] Unfortunately, the conductive film may be deposited on the sides of the substrate holder and the electrically insulating layer to create a short circuit between the conductive substrate holder and the body of the chuck. Summary of the invention

[0008] One aspect of the present disclosure is a chuck system for performing a substrate biased atomic layer deposition (ALD) process that forms a conductive film on a substrate. The chuck system includes: a conductive substrate holder configured to support a substrate; a conductive base; and an electrical isolation layer sandwiched between the conductive substrate holder and the conductive base and having an outer edge, wherein at least one edge recess is formed in and extends around the outer edge, the at least one edge recess having an interior and being sized to prevent the conductive film from coating the entire interior of the at least one edge recess during the substrate biased ALD process.

[0009] Another aspect of the present invention is an ALD system comprising a chuck system as described immediately above, and further comprising a reaction chamber having an interior, wherein the chuck system is disposed within the reaction chamber interior.

[0010] Another aspect of the present disclosure is an electrical isolation layer for a chuck system for performing a substrate biased ALD process to deposit a conductive film. The electrical isolation layer includes: a monolithic disk made of a single electrically insulating material, the disk having an outer edge and having a thickness TH defined by a range of 0.1" (2.5 mm) ≤ TH ≤ 0.50.5" (12.7 mm); and a recess formed in and extending around the outer edge, the recess having a height dimension h in the range of 0.01" (0.25 mm) ≤ h ≤ 0.05" (1.27 mm) and a depth dimension d in the range of 0.20" (5.1 mm) ≤ d ≤ 4" (101.6 mm), but with the condition that d / h is in the range of 20 ≤ d / h ≤ 100.

[0011] Another aspect of the present disclosure is an electrically isolating layer for a chuck system for performing a substrate biased ALD process to deposit a conductive film. The electrically isolating layer includes: an upper member made of an electrically insulating material or a conductive material; a lower member made of an electrically insulating material or a conductive material; and an intermediate member made of an electrically insulating material and sandwiched between the upper member and the lower member to define a layered structure having an outer edge, wherein the intermediate member is sized to define an edge recess in the outer edge and extend around the outer edge; and wherein the edge recess has a height dimension h in the range of 0.01" (0.25 mm) ≤ h ≤ 0.05" (1.27 mm) and a depth dimension d in the range of 0.20" (5.1 mm) ≤ d ≤ 4" (101.6 mm), but with the proviso that d / h is in the range of 20 ≤ d / h ≤ 100.

[0012] Additional features and advantages are set forth in the following detailed description, and in part will be apparent to those skilled in the art from the description or learned by practicing the embodiments as described in the written description and claims thereof and the accompanying drawings. It should be understood that the foregoing general description and the following detailed description are merely exemplary and are intended to provide an overview or framework for understanding the nature and character of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings are included to provide a further understanding and are incorporated into and constitute a part of this specification. The accompanying drawings illustrate one or more embodiments and together with the detailed description explain the principles and operations of the various embodiments. As such, the present disclosure will be more fully understood through the following detailed description in conjunction with the accompanying drawings, in which:

[0014] Figure 1 is a schematic diagram of an example atomic layer deposition (ALD) system configured to perform substrate biased ALD;

[0015] Figure 2A is a top view of an example chuck system as disclosed herein;

[0016] Figure 2B yes Figure 2A A side view of an example chuck system;

[0017] Figure 3A is an elevated isometric view of an example electrical isolation layer according to the present disclosure and used in Figure 2A and 2B In the chuck system;

[0018] Figure 3B is a close-up cross-sectional view of an edge portion of an electrically isolating layer, illustrating an example cross-sectional configuration of an edge recess;

[0019] Figure 3Cis a close-up cross-sectional view of an edge portion of a chuck system illustrating how a conductive ALD film coats the chuck system and how an edge recess in the isolation layer functions to form a break in the conductive film to maintain electrical isolation between a substrate holder and a chuck base;

[0020] Figure 4A and 4B Similar to Figure 3A and 3B , and illustrates an example embodiment of an electrically isolating layer including a plurality of edge recesses;

[0021] FIG. 5A to FIG. 5D Similar to Figure 3B , and illustrates other example configurations of edge recesses formed in an electrical isolation layer;

[0022] Figure 6 is a side view of an example electrical isolation layer formed from three components arranged in a layered configuration;

[0023] Fig. 7A is a top view of an example electrical isolation layer formed from two components, namely, an annular outer component and a center component, showing the components side by side;

[0024] Figure 7B is a close-up cross-sectional view of edge portions of the annular outer member and the center member; and

[0025] Figure 8 3 and illustrates an example embodiment in which the edge recess is pneumatically coupled to an inert gas source such that the inert gas can flow radially outward from the edge recess. DETAILED DESCRIPTION

[0026] Reference is now made in detail to various embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Whenever possible, the same or similar reference numerals and symbols are used throughout the drawings to refer to the same or similar parts. The drawings are not necessarily drawn to scale, and those skilled in the art will recognize that the drawings have been simplified to illustrate key aspects of the present disclosure. In particular, the scale of the chuck system is exaggerated in the z direction for ease of illustration and to better illustrate key features of the chuck system and, in particular, the electrical isolation layer.

[0027] The protection scopes described below are incorporated into and constitute a part of this detailed description.

[0028] ALD System

[0029] Figure 1is a schematic diagram of an example atomic layer deposition (ALD) system 10, which includes a chuck system 100 as disclosed herein and described in more detail below. The chuck system 100 is configured to support a substrate 40 having an upper surface 42. The example ALD system 10 is one of the Fiji series modular, high vacuum plasma-based ALD systems available from Ultratech, Inc. of Waltham, Massachusetts. The chuck system 100 can also be used in other types of ALD systems, such as non-plasma ALD systems. The chuck system 100 includes a voltage source 200 that provides a bias voltage to the substrate 40 when an ALD process is performed using the ALD system 10 to deposit a conductive film ("conductive film") 50. Example conductive films include W, TiN, TaN, MoN, NbN, ZnO, etc. An ALD process that uses a voltage bias on the substrate 40 is referred to herein as "substrate biased ALD" or "voltage biased ALD".

[0030] The ALD system 10 includes a reaction chamber 14 having a central axis A1 extending in the z-direction. The reaction chamber 14 is defined by at least one sidewall 16. The reaction chamber 14 includes a chamber interior ("interior") 18. The ALD system 10 may include a plasma source 20 operably disposed relative to the reaction chamber 14 and forming a plasma 22.

[0031] The ALD system 10 also includes precursor gas sources 60 and 80, which are configured to provide (e.g., introduce) precursor gases 62 and 82, respectively. In an example, the introduction of precursor gases 62 and 82 can be managed via the operation of a controller (not shown), or can also be done manually. The ALD system 10 also includes an inert gas source 90, which provides an inert gas 92 (e.g., nitrogen, argon, etc.) to purge the interior 18.

[0032] The ALD system 10 also includes a vacuum system 96 to evacuate the interior 18 to initiate the ALD-based process, as well as to assist in removing excess precursor gases 62 and 82 during the various ALD steps.

[0033] Chuck system

[0034] Figure 2A is a top view of an example chuck system 100 according to the present disclosure, and Figure 2B The chuck system 100 includes a central axis A2 extending along the z-direction and coaxial with the central axis A1 of the reaction chamber 14 in the example.

[0035] In an example, the chuck system 100 includes a substrate holder 110 having an upper surface 112, a lower surface 114, and an outer edge 116. The upper surface 112 of the substrate holder 110 is configured to support a substrate 40. The substrate holder 110 is made of a conductive material (e.g., copper, stainless steel, etc.) and is electrically connected to a voltage source 200. The voltage source 200 provides a voltage signal 202 to the substrate holder 110 and thus to the substrate 40, thereby electrically biasing the substrate relative to ground.

[0036] For certain types of ALD reactions, electrical biasing of substrate 40 can be used to attract selected ions in the precursor gas to enhance the ALD process (e.g., increase deposition rate) and / or change film properties, such as changing conductivity, changing film density, changing internal film stress, or altering superconducting properties of the film. The substrate holder 110 is sized to operably support substrates of various sizes, including conventional semiconductor wafer sizes of 100 mm or 200 mm or 300 mm or even larger. In an example, substrate holder 110 can have a thickness of approximately 0.25" (6.4 mm).

[0037] The chuck system 100 also includes a pedestal 120 having an upper surface 122, a lower surface 124, and an outer edge 126. The pedestal 120 is typically made of a conductive material. In an example, the pedestal 120 includes a heater 130 for heating the pedestal, and a substrate holder 110 that heats the substrate 40 to an initial temperature suitable for the ALD process. The pedestal 120 and the reaction chamber 14 are electrically grounded. In an example, the pedestal 120 can have a thickness in the range of 0.25" (6.4 mm) to 3" (76.2 mm) and has a diameter that substantially matches the diameter of the substrate holder 110. The pedestal 120 can be made of copper, stainless steel, or a similar conductive material.

[0038] The chuck system 100 also includes an electrical isolation layer 150 sandwiched between the base 120 and the substrate holder 110 for electrically isolating the conductive base from the conductive substrate holder. The electrical isolation layer 150 has a body 151, an upper surface 152, a lower surface 154, and an outer edge 156. In an example, the electrical isolation layer 150 is planar and has a thickness TH and a diameter D. In an example, the thickness TH is within a range defined by 0.1" (2.5 mm) ≤ TH ≤ 0.5 (12.7 mm).

[0039] The two main requirements for the material used to form the electrical isolation layer 150 are that it is electrically insulating and able to withstand the maximum temperature of a given ALD process, which can typically be in the range of 25°C to 500°C. Example materials for the electrical isolation layer 150 include electrically insulating materials such as glass, ceramics, plastics, thermoplastics, polyamides (nylons), polyimides (Kapton), epoxies, polymers, and polycarbonates. In an example, the electrical isolation layer 150 is in the form of a thin disk. In an example, the electrical isolation layer 150 is monolithic, that is, formed as a single piece made of a single material. In other examples discussed below, the electrical isolation layer 150 is formed of two or more separate components, including components made of different materials.

[0040] Figure 3A is a top plan view of an example electrical isolation layer 150, and Figure 3B 1 is a close-up cross-sectional view of an edge portion of the electrically isolating layer. The electrically isolating layer 150 includes at least one recess 160 formed in the outer edge 156, and is therefore referred to as an "edge recess" hereinafter. In the example, the at least one edge recess 160 extends radially inward toward the central axis A2. In the example, the at least one edge recess 160 has a directional component radially inward toward the central axis A2. Unless otherwise specified, the following discussion refers to a single edge recess 160 for ease of discussion.

[0041] The edge recess 160 extends around the entire outer edge 156, as shown in FIG. Figure 2A As indicated by the dotted circle in Figure 3A As shown. Figure 3B As shown in a close-up xz cross-sectional view of , in one example, the edge recess 160 can have a rectangular cross-sectional shape. In the example, the edge recess 160 has an upper wall 162, a lower wall 164, and an end wall 166 that define a recess interior 167. The edge recess 160 has a depth dimension d measured radially inward from the outer edge 156. The edge recess 160 also has a height dimension h measured in the z direction. As discussed below, in other embodiments, the depth and height dimensions (d, h) can vary with position, i.e., need not be constant. In such examples, the depth and height dimensions (d, h) can be considered to be minimum dimensions.

[0042] As described above, the ALD process is highly conformal. The ALD process also ultimately coats more than just the substrate upper surface 42. Therefore, in practice, the ALD process not only deposits the ALD film 50 on the substrate upper surface 42, but also coats the exposed upper surface 112 of the substrate holder 110, the outer edge 116 of the substrate holder, the outer edge 156 of the isolation layer 150, and the outer edge 126 of the pedestal 120 with the ALD film 50. When the ALD film 50 is conductive, the ALD film can provide an electrical path between the conductive substrate holder 110 and the conductive pedestal 120 over the outer edge 156 of the isolation layer 150, thereby creating a short circuit, which is problematic for voltage biased ALD applications.

[0043] Because the ALD process is conformal and can cover high aspect ratio features, the edge recess 160 needs to have a sufficiently high aspect ratio AR = d / h so that the ALD film cannot coat all of the walls 162, 164, and 166 of the edge recess. If this happens, then as described above, the conductive ALD film will be able to define an electrical path between the substrate holder 110 and the pedestal 120 and create a short circuit around the electrically isolating layer 150. Therefore, in an example, for a given ALD process, the edge recess 160 has a sufficiently large aspect ratio AR = d / h to prevent the formation of a short circuit.

[0044] The aspect ratio AR = d / h is best suited for simple rectangular recesses 160. More complex edge recesses can utilize an equivalent aspect ratio AR E , which can be derived empirically through simulation or experiment.

[0045] Figure 3C Similar to Figure 3B , and illustrates the effect of the edge recess 160 on the deposition process of the conductive ALD film 50 on the chuck system 100. The conductive ALD film 50 (or a modified version thereof) covers the exposed upper surface 112 of the substrate holder 110, the outer edge 116 of the substrate holder, the outer edge 156 of the isolation layer 150, and the outer edge 126 of the pedestal 120. The conductive ALD film 50 will also attempt to cover the interior 167 of the edge recess 160, i.e., the inner walls 162, 164, and 166. However, because the aspect ratio AR of the edge recess 160 is large enough, the conductive ALD film 50 will only be able to partially extend into the recess interior 167 toward the end wall 166, leaving an uncoated portion 170 of the recess interior defining a gap 172 in the conductive ALD film 50. The gap 172 in the conductive ALD film 50 prevents a short circuit from developing between the conductive support holder 110 and the conductive pedestal 120 through or over the isolation layer 150.

[0046] Experiments have shown that for most ALD processes for forming the conductive film 50, a suitable aspect ratio AR is AR ≥ 50. For some films, an aspect ratio of AR ≥ 20 is suitable. In other examples, the aspect ratio may be set to AR ≥ 100. Therefore, in various embodiments, the aspect ratio may be in the range of 20 ≤ AR ≤ 100 or 50 ≤ AR ≤ 100.

[0047] In an example, the height h is in the range of 0.01" (0.25 mm) ≤ h ≤ 0.05" (1.27 mm), and the depth d is in the range of 0.20" (5.1 mm) ≤ d ≤ 6" (152.4 mm), or 0.20" (5.1 mm) ≤ d ≤ 4" (101.6 mm), or 0.20" (5.1 mm) ≤ d ≤ 1" (25.4 mm). Therefore, in one example, h = 0.01" (2.5 mm) and d = 50h = 0.5" (12.7 mm).

[0048] The upper limit of the aspect ratio AR may be constrained at least in part by the effect of the edge recess 160 on heat transfer from the pedestal 120 to the substrate holder 110 through the electrical isolation layer 150. It is generally preferred that the substrate 40 have a substantially uniform temperature, for example, within a 5% variation range, or more preferably within a 2% variation range or within a 1% variation range. It is believed that this temperature uniformity requirement will not greatly constrain the size and shape of the edge recess 160.

[0049] When the depth d of the edge recess 160 is very large, the upper limit of the aspect ratio AR may also be constrained at least in part by the physical stability of the substrate holder 110. In addition, the upper limit of the aspect ratio AR may be limited by the technical capabilities (i.e., manufacturing limitations) to make the edge recess 160 very thin (small h) without the upper and lower walls touching.

[0050] Figure 4A and 4B Similar to Figure 3A and 3B And illustrated is an exemplary embodiment in which the isolation layer 150 includes a plurality of edge recesses 160, wherein four such edge recesses are exemplarily shown. The use of a plurality of edge recesses 160' provides electrical isolation redundancy.

[0051] FIG. 5A to FIG. 5D Similar to Figure 3B Also illustrated are other example configurations of edge recesses 160 formed in electrical isolation layer 150 . Figure 5AAn exemplary configuration of the edge recess 160 is shown having a “T” shape in a cross-section taken radially relative to the electrical isolation layer, which makes the conductive ALD film 50 even more difficult to deposit within the edge recess because the ALD deposition must pass through two corners 168 and enter two different branches 61 of the edge recess 160. Figure 5B and 5C Similar to Figure 5A Two complex configurations of the edge recess 160 are shown, each including an additional corner 168 defining an additional branch 161 , which makes it increasingly difficult for the conductive ALD film 50 to be deeply deposited in the interior 167 of the corresponding edge recess.

[0052] Figure 5D An example edge recess 160 is illustrated that includes curved upper and lower walls 162 , 164 and curved end walls 166 .

[0053] In general, the cross-sectional shape of the edge recess 160 can have any reasonable configuration. In an example, the electrical isolation layer 150 is formed using a 3D printing process using conventional three-dimensional (3D) printing technology. Current 3D printing technology is capable of defining extremely complex and labyrinthine configurations for the edge recess 160, such as a configuration including multiple branches 161. In an example where the edge recess 160 is formed using conventional milling technology, it would be preferable to use a simple edge recess configuration, such as Figure 3B Rectangular cross-sectional shape.

[0054] Figure 6 1 is a side view of an example electrical isolation layer 150, which is made of three separate parts, namely, an upper part 182, a lower part 184, and an intermediate part 183 sandwiched between the upper part and the lower part. In the example, at least the intermediate part 183 is made of an electrically insulating material. The edge recess 160 can be defined by making the intermediate part 183 smaller than the upper part 182 and the lower part 184 (i.e., having a smaller diameter). In the example, the upper and lower parts do not need to be electrically insulating, for example, they can be made of aluminum or stainless steel. In an example, a high temperature resistant adhesive is used to fix the upper part, the middle part, and the lower part to form a laminated structure. In another example, the upper part, the middle part, and the lower part can be fixed using screws or other fastening devices.

[0055] Fig. 7A 1 is a top view of another example of an electrically isolating layer 150 made of two main components, namely, a center piece 186 having a periphery 187 and an annular outer piece 188 having an inner edge 189. The inner edge 189 defines a central opening CH that is sized to closely accommodate the center piece 186, with the periphery 187 of the center piece 186 disposed proximate to (e.g., in contact with) the inner edge 189 of the annular outer piece 188.

[0056] The annular outer member 188 is made of an insulating material and includes an inner edge 189 and also defines an outer edge 156 in which an edge recess 160 is formed. In an example, the center member 186 may be a disk made of a conductive material such as aluminum or stainless steel. The center member 186 may also be made of an insulating material. Figure 7B As shown in a close-up cross-sectional view, the annular outer member 188 and the center member 186 may include complementary engagement features 190 that facilitate engagement and securing the members to one another, such as via an adhesive 192.

[0057] Figure 8 3 and illustrates an embodiment of an electrically isolating layer 150 in which an edge recess 160 is pneumatically connected to an inert gas source 90 via a gas line 91. The gas line 91 supports the flow of an inert gas 92 into the edge recess 160, such as at or near the end wall 166. Due to the vacuum in the interior 18 of the reaction chamber 14, the inert gas 92 flows into the recess interior 167 and then radially outward until it exits the edge recess 160 at the edge 156. This flow of inert gas 92 substantially prevents ALD gas from entering the edge recess and depositing on the walls therein. In this "pressurized" embodiment of the electrically isolating layer 150, the edge recess 160 can have an aspect ratio AR that is smaller than that of the "non-pressurized" embodiment.

[0058] Example ALD Process

[0059] One aspect of the present disclosure is to use Figure 1 The ALD system 10 and the chuck system 100 shown in FIG. 1 are used to form an ALD process for forming a conductive film 50. The ALD process includes operably supporting a substrate 40 on a substrate holder 110 of the chuck system 100 within a reaction chamber 14 and then evacuating the chamber. The method may include heating the substrate 40 to an initial processing temperature using a heater 130. An example initial temperature may be in the range of 25° C. to 500° C.

[0060] A bias voltage is then applied to the substrate holder 100 via a bias voltage signal 202 from a voltage source 200. An example bias voltage may be a DC, -100V to +100V or an RF AC voltage. The RF voltage may have a frequency range of 10 kilohertz to 100 megahertz. The peak-to-peak voltage of the RF signal is determined by the power setting (0 watts to 300 watts) and may range from 0 watts to 600 watts. The bias voltage is set to just under half of the peak-to-peak voltage.

[0061] The method then includes introducing a first precursor gas 62 into the chamber interior 18, wherein the first precursor gas includes a metal M. For example, metal-containing precursor gases for ALD are well known in the art and may include a metal such as tungsten or titanium. The metal M in the first precursor gas adheres to the substrate upper surface 42, i.e., the metal M chemisorbs with pre-existing chemical moieties on the substrate surface.

[0062] The method then includes purging the first precursor gas from the chamber interior 18 using a purge gas 92. The method then includes introducing a second precursor gas 82 into the chamber interior, which reacts with the chemically adsorbed metal on the substrate surface 42 to form a first atomic layer of the conductive film 50. The above process is then repeated to build up the conductive film layer by layer. The process may also include using additional precursor gases (i.e., more than two precursor gases) and purge steps.

[0063] The method includes depositing the conductive film 50 on the outer edge of the chuck system, including the outer edge 156 of the electrically insulating layer 150 and only within a portion of the interior of the edge recess 160, leaving a gap 172 in the conductive film defined in the edge recess (see, e.g. Figure 3C ) of the uncoated portion 170. The gap 172 is used to maintain electrical isolation between the substrate holder 110 and the susceptor 120 during the ALD process.

[0064] In an example, the method may include flowing the purge gas 92 radially outward from the edge recess 160 to prevent the precursor gases 62 and 82 from entering the edge recess.

[0065] It will be apparent to those skilled in the art that various modifications may be made to the preferred embodiments of the present disclosure as described herein without departing from the spirit or scope of the present disclosure as defined in the appended claims. Therefore, the present disclosure encompasses modifications and variations as long as they fall within the scope of the appended claims and their equivalents.

Claims

1. A chuck system for performing a substrate biased atomic layer deposition (ALD) process, wherein the process forms a conductive film on a substrate, the chuck system comprising: a conductive substrate holder configured to support the substrate, wherein the conductive substrate holder has an upper surface exposed when supporting the substrate and an outer edge extending around the conductive substrate holder; a conductive base having an outer edge extending around said conductive base; as well as an electrically isolating layer sandwiched between the conductive substrate holder and the conductive base and having an outer edge extending around the electrically isolating layer, wherein during use, the conductive film is deposited on the upper surface of the substrate, the exposed upper surface of the conductive substrate holder, the outer edge extending around the conductive substrate holder, the outer edge extending around the electrical isolation layer, and the outer edge extending around the conductive base, wherein at least one edge recess is formed in and extends around the outer edge of the electrical isolation layer, the at least one edge recess having an interior and being sized to prevent the conductive film from coating the entire interior of the at least one edge recess when the conductive film is deposited on the outer edge of the electrical isolation layer during an ALD process in which the substrate is biased. 2 . The chuck system of claim 1 , wherein the at least one edge recess has a height dimension h defined by the range 0.01” (0.25 mm) ≤ h ≤ 0.05” (1.27 mm).

3. The chuck system of claim 1, wherein the at least one edge recess has a depth dimension d defined by the range 0.20" (5.1 mm) ≤ d ≤ 4" (101.6 mm). The chuck system of claim 1 , wherein the at least one edge recess has an aspect ratio AR≧20. 5 . The chuck system of claim 1 , wherein the at least one edge recess has an aspect ratio AR defined by a range of 50≦AR≦100.

6. The chuck system of claim 1, wherein the at least one edge recess has a rectangular cross-sectional shape.

7. The chuck system of claim 1, wherein the electrically isolating layer has a thickness TH defined by a range of 0.1" (2.5 mm) ≤ TH ≤ 0.5" (12.7 mm).

8. The chuck system of claim 1, wherein the electrically isolating layer is monolithic and made of a single electrically insulating material.

9. The chuck system of claim 1, wherein the at least one edge recess comprises at least one branch.

10. The chuck system of claim 1, wherein the electrically isolating layer is formed from a first component and a second component made of different materials, wherein at least one of the different materials is an electrically insulating material.

11. The chuck system of claim 1, wherein the electrically isolating layer is formed of at least a first component, a second component, and a third component, wherein at least one of the components is made of an electrically insulating material.

12. The chuck system of claim 1, wherein the electrically isolating layer is made of at least one material selected from the group consisting of glass, ceramic, plastic, thermoplastic, polyamide (Nylon), polyimide (Kapton), epoxy, polymer, and polycarbonate.

13. The chuck system of claim 1, wherein the at least one edge recess comprises a plurality of edge recesses.

14. The chuck system of claim 1, further comprising: Inert gas source; as well as A gas line pneumatically connects a source of inert gas to the interior of at least one edge recess.

15. An atomic layer deposition (ALD) system, comprising: The chuck system according to any one of claims 1 to 14; as well as A reaction chamber is provided having an interior, wherein the chuck system is disposed within the interior of the reaction chamber.

16. An atomic layer deposition (ALD) process for forming a conductive film on an upper surface of a substrate, the ALD process comprising: The substrate is supported on a chuck system within a reaction chamber of the ALD system, the chuck system comprising: a conductive substrate holder configured to support the substrate, wherein the conductive substrate holder has an upper surface exposed when supporting the substrate and an outer edge extending around the conductive substrate holder; a conductive base having an outer edge extending around the conductive base; and an electrically isolating layer sandwiched between the conductive substrate holder and the conductive base and having an outer edge extending around the electrically isolating layer, wherein the electrically isolating layer has at least one recess formed in the outer edge, the at least one recess having an interior sized to prevent the conductive film from coating the entire interior when the conductive film is deposited onto the outer edge of the electrically isolating layer; applying a bias to the conductive substrate holder to bias the substrate; and A first precursor gas and a second precursor gas are alternately introduced with a purging step between the alternate introductions of the first precursor gas and the second precursor gas so as to form the conductive film on the upper surface of the substrate, the conductive film being deposited on the upper surface of the substrate, the exposed upper surface of the conductive substrate holder, the outer edge extending around the conductive substrate holder, and the outer edge extending around the conductive base, wherein the conductive film is also deposited on the outer edge of the electrical isolation layer and within only a portion of the interior so as to define a gap within the interior of the recess and within the conductive film between the conductive substrate holder and the conductive base.

17. The ALD process of claim 16, wherein the at least one recess comprises a plurality of recesses.

18. The ALD process of claim 16, wherein the at least one recess has a height dimension h in the range of 0.01" (0.25 mm) ≤ h ≤ 0.05" (1.27 mm), a depth dimension d in the range of 0.20" (5.1 mm) ≤ d ≤ 4" (101.6 mm), provided that d / h is in the range of 20 ≤ d / h ≤ 100.

19. The ALD process of claim 16, further comprising providing an inert gas into the interior of at least one recess such that the inert gas flows out of the interior of the at least one recess at the outer edge of the electrical isolation layer.

20. The ALD process of claim 16, further comprising forming the electrically isolating layer as a single monolithic piece from a single electrically insulating material.

21. The ALD process of claim 16, further comprising forming the electrical isolation layer from at least two components.

22. The ALD process of claim 16, further comprising forming the electrical isolation layer using a three-dimensional (3D) printing process.

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