Arcuate substrate clamping method, device and system

Abstract

Methods and apparatus for gripping a substrate include: i. Placing a substrate on a gripping surface of a substrate support having a plurality of mutually spaced electrodes including a first electrode and a second electrode; ii. Measuring a substrate bow of the substrate; iii. Determining a first voltage to be applied to the first electrode and a second voltage to be applied to the second electrode based on the measured substrate bow, wherein the first voltage is an AC voltage and the second voltage is an AC or DC voltage; and iv. Applying a first voltage to the first electrode and a second voltage to the second electrode to clamp the substrate to the substrate support.

Description

Technical Field

[0001] Embodiments of the present case generally relate to substrate clamping, and more particularly to the clamping of bowed substrates. Background Art

[0002] Substrates such as semiconductor wafers may have a certain degree of bow, making it more difficult to clamp the substrate to a chuck. For example, without an unacceptably high clamping voltage, such bowed substrates may be difficult to clamp to an electrostatic chuck (ESC) due to a large gap between the ESC and the substrate. The high clamping voltage results in a large clamping force between some areas of the substrate and the ESC, thereby increasing the friction between the substrate and the ESC and causing improper particle generation.

[0003] Accordingly, the inventors have proposed new methods, systems, and devices for clamping substrates that can use a lower clamping voltage to reduce or eliminate the generation of defective particles to accommodate bowed substrates. Summary of the Invention

[0004] Methods and devices for clamping substrates are provided herein. In some embodiments, a method for clamping a substrate includes: i. placing the substrate on a clamping surface of a substrate support having a plurality of electrodes spaced apart from each other including a first electrode and a second electrode; ii. measuring the substrate bow of the substrate; iii. determining a first voltage to be applied to the first electrode and a second voltage to be applied to the second electrode based on the measured substrate bow, wherein the first voltage is an AC voltage and the second voltage is an AC or DC voltage; and iv. applying the first voltage to the first electrode and the second voltage to the second electrode to clamp the substrate to the substrate support.

[0005] In some embodiments, a system for clamping a substrate includes: a substrate support having a surface for supporting the substrate; a plurality of electrodes spaced apart from each other in or on the substrate support, the plurality of electrodes including a first electrode and a second electrode; and a controller configured to receive a measurement of the substrate bow of the substrate and determine a first voltage to be applied to the first electrode and a second voltage to be applied to the second electrode based on the substrate bow, and apply the first voltage to the first electrode and the second voltage to the second electrode, wherein the first voltage is an AC voltage and the second voltage is an AC or DC voltage.

[0006] In some embodiments, a non - transitory computer - readable storage medium stores instructions that, when executed by a processor of a system having a substrate support with a plurality of electrodes including a first electrode and a second electrode spaced apart from each other for clamping a substrate, perform a method of clamping a substrate, the method including: i. placing the substrate on a clamping surface of a substrate support having a plurality of electrodes including a first electrode and a second electrode spaced apart from each other; ii. measuring a substrate bow of the substrate; iii. determining a first voltage to be applied to the first electrode and a second voltage to be applied to the second electrode based on the measured substrate bow, wherein the first voltage is an AC voltage and the second voltage is an AC or DC voltage; and iv. applying the first voltage to the first electrode and the second voltage to the second electrode.

[0007] Other embodiments and additional embodiments of the present case are described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The embodiments of the present case are briefly outlined above. The embodiments of the present case will be discussed in more detail below. The embodiments of the present case can be understood by referring to the illustrative embodiments of the present case depicted in the drawings. However, the drawings only illustrate the typical embodiments of the present case and should not be considered as limiting the scope of the present case, as the present case admits other equivalent embodiments.

[0009] Figure 1 is a top plan view of a substrate support according to an embodiment of the present case.

[0010] Figure 2 is along Figure 1 section 2 - 2 of Figure 1 the cross - sectional view of the substrate support shown.

[0011] Figure 3 Shows a Figure 2 substrate support according to an embodiment of the present case, which is modified to have electrodes in multiple planes.

[0012] Figure 4 Shows a Figure 2 substrate support according to an embodiment of the present case, which has electrodes connected to an AC and a DC voltage supply.

[0013] Figure 5 Shows a Figure 4 substrate support according to an embodiment of the present case, which is modified to have electrodes in multiple planes.

[0014] Figure 6A is a cross - sectional view of another substrate support according to an embodiment of the present case.

[0015] Figure 6B is a cross - sectional view of another substrate support according to an embodiment of the present case.

[0016] Figure 6C is a cross-sectional view of another substrate support according to an embodiment of the present case.

[0017] Figure 7 is a plan view of the arrangement of electrodes according to an embodiment of the present case.

[0018] Figure 8 is a plan view of the arrangement of electrodes according to an embodiment of the present case.

[0019] Figure 9 is a plan view of the arrangement of electrodes according to an embodiment of the present case.

[0020] Figure 10 is a plan view of the arrangement of electrodes according to an embodiment of the present case.

[0021] Figure 11A Shows the interdigitated arrangement of electrodes according to an embodiment of the present case.

[0022] Figure 11B Shows the interdigitated and staggered arrangement of electrodes according to an embodiment of the present case.

[0023] Figure 12 Shows a method of clamping a substrate according to an embodiment of the present case.

[0024] Figure 13 Shows another method of clamping a substrate according to an embodiment of the present case.

[0025] Figure 14 is a cross-sectional view of a substrate support and an arcuate substrate in an unclamped configuration according to an embodiment of the present case.

[0026] Figure 15 Shows clamped to Figure 14 of the substrate support Figure 14 substrate.

[0027] Figure 16 Shows a clamped substrate and a substrate support in a processing chamber and clamped to an electrostatic chuck according to an embodiment of the present case Figure 15 of.

[0028] Figure 17 Shows another embodiment of a substrate support according to an embodiment of the present case.

[0029] Figure 18 Shows another embodiment of a substrate support according to an embodiment of the present case.

[0030] Figures 19 to 21 Shows a method of controlling the bow of a substrate according to an embodiment of the present case.

[0031] Figure 22 Shows another embodiment of a substrate support according to an embodiment of the present case.

[0032] Figure 23 Shows another embodiment of a substrate support according to an embodiment of the present case.

[0033] For ease of understanding, the same reference numerals have been used, where possible, to identify common and identical elements in the figures. The figures are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be beneficially incorporated into other embodiments without further recitation. Detailed Embodiments

[0034] Embodiments of methods, systems, and devices for clamping a substrate are provided herein. Such methods, systems, and devices may control the clamping of a substrate based on measurements of the bow of the substrate. Additionally, embodiments of methods, systems, and devices for controlling the bow of a substrate are provided herein.

[0035] Figure 1 Shows a plan view of a substrate support 100 according to an embodiment of the present case. In some embodiments, and as Figures 1 to 5 shown, the substrate support 100 may include a base 102 and a plurality of electrodes 104 embedded in the base 102 and spaced apart from each other. In some embodiments, and as Figures 1 to 5 shown, the plurality of electrodes 104 may be concentrically arranged. In some embodiments, the base 102 may be formed of at least one dielectric material, such as ceramic oxides, nitrides, polymers such as polyimide (PI), benzocyclobutene (BCB), etc., or semiconductors (such as silicon). In some embodiments, the plurality of electrodes 104 may be formed of metal, for example, by screen printing and sintering metal electrodes within the base.

[0036] In some embodiments, the substrate support 100 may be used as an electrostatic chuck. In some embodiments, and as will be discussed more fully below, the substrate support 100 may be used as a transfer carrier that can be clamped to a substrate and moved between processing chambers in a substrate processing system (such as in a cluster tool).

[0037] In some embodiments, and as Figures 2 to 5 shown, the substrate support may include a plurality of mesa 106 extending axially (relative to the central axis A) from the base 102 to a contact area 108 to contact the substrate. The contact areas 108 of the plurality of mesa 106 may together define the contact surface of the substrate support 100. In some embodiments, and as Figures 2 to 5As shown, the table tops 106 can be radially spaced apart from each other relative to the central axis A. In some embodiments, and as Figures 2 to 5 shown, all the table tops 106 have equal heights. As described in more detail below, in some embodiments, and as Figure 20 and Figure 21 shown, the table tops 106 can have different heights.

[0038] In some embodiments, and as Figures 1 to 5 shown, a plurality of electrodes 104 can be radially spaced apart from each other relative to the axis A. Additionally, in some embodiments, and as Figure 3 and Figure 5 shown, a plurality of electrodes 104 can be axially spaced apart relative to the central axis A. Additionally, in some embodiments, the widths (measured radially) of the plurality of electrodes 104 may be the same. In some embodiments, and as Figures 2 to 5 shown, the widths of the plurality of electrodes 104 may be different.

[0039] In some embodiments, and as Figures 2 to 5 shown, the plurality of electrodes 104 can be configured to be connected to one or more voltage suppliers for generating static charges to clamp a substrate to the substrate support 100. In some embodiments, and as Figure 2 shown, the base 102 can have holes 202 exposing the plurality of electrodes 104, and these holes 202 may be removably connected to metal pins (such as POGO pins) or contacts 204 connected to the voltage supplier 110. In some embodiments, and as Figure 3 shown, the wiring 302 can be embedded in the base 102, extending from each electrode 304 to corresponding contacts 304 on the outer (e.g., lower) surface 306 of the base 102. In some embodiments, the contacts 304 can be flush with the outer surface 306 (as Figure 3 shown), or can be recessed. These contacts 304 may be removably connected to metal pins (such as POGO pins) (not shown) or contacts 308 connected to the voltage supplier 110. Additionally, in some embodiments, the embedded wiring 302 and the plurality of electrodes 104 can be formed together by screen printing and sintering metal traces within the base 102. In some embodiments, a single voltage supplier can be used and can be connected to the plurality of electrodes 104 using a multiplexer.

[0040] In some embodiments, and as Figures 1 to 5 shown, the plurality of electrodes 104 can include a first electrode 104a and a second electrode 104b, and the voltage supplier 110 can be configured to apply a first voltage to the first electrode 104a and a second voltage to the second electrode 104b. In some embodiments, the first voltage is an AC voltage, and the second voltage is an AC voltage (Figure 2 and Figure 3 ) or a DC voltage ( Figure 4 and Figure 5 ). The voltage supplier 110 may be configured to apply the first voltage and the second voltage simultaneously or sequentially.

[0041] In some embodiments, and as Figure 2 and Figure 3 shown, the first electrode 104a is connected to the voltage supplier 110 to receive an AC voltage, and the second electrode 104b is connected to the voltage supplier 110 to receive an AC voltage. In some embodiments, one or more of the voltage suppliers may be operably coupled to a controller that is configured to control the application of voltage to the plurality of electrodes 104. For example, in some embodiments, the controller may control one or more voltage suppliers 110 that may be configured to supply an AC or DC voltage. Each voltage supplier 110 may be configured to independently control the amplitude, phase, frequency, and duty cycle (for an AC voltage) supplied to one or more of the plurality of electrodes 104. In some embodiments, and as Figure 4 and Figure 5 shown, the first electrode 104a is connected to a voltage supplier 110 configured to supply an AC voltage, and the second electrode 104b is connected to a voltage supplier 110 configured to supply a DC voltage. In some embodiments, the second electrode may also be connected to a voltage supplier 110 configured to supply an AC voltage such that the AC voltage may be superimposed on the DC voltage.

[0042] Figure 6A Exemplary embodiments of the substrate support 100 showing a substrate support arrangement as Figure 1 shown, but wherein the base 102 includes an upper dielectric layer 602a and a lower dielectric layer 602b. In the Figure 6A illustrated embodiment, holes 202 are formed in the lower dielectric layer 602b.

[0043] In some embodiments, the upper dielectric layer 602a and the lower dielectric layer 602b may be formed of one or more dielectric materials such as ceramic oxides, nitrides, polymers (such as PI, BCB), or semiconductors (such as silicon). In some embodiments, and as Figure 6A shown, at least a portion of the base 102 may have a dielectric coating 604. In some embodiments, as Figure 6A shown, the plurality of electrodes 104 may be located in the upper dielectric layer 602a.

[0044] In some embodiments, and as Figure 6B shown, may be modified Figure 6AThe substrate support 100 shown, such that a plurality of electrodes 104 are located in the lower dielectric layer 602b. In some embodiments, at least one of the plurality of electrodes 104 may be located in two or more dielectric layers, such as the upper dielectric layer 602a and the lower dielectric layer 602b. Additionally, in some embodiments, and as Figure 6C shown, the substrate support shown may be further modified by including an embedded material layer 606 made of an insulator, a conductor (such as a metal), or a polymer. Figure 6B The substrate support shown.

[0045] Figures 7 to 11B Another embodiment of an electrode arrangement for a substrate support according to the present case is shown. In Figures 7 to 10 the embodiment shown, two electrodes are shown. In other embodiments, more than two electrodes may be arranged. In Figure 7 the embodiment shown, the first electrode 702 may be arranged as a grid or a wireframe, and the second electrode 704 may be formed as a square above or below the first electrode 702. In some embodiments, and as Figure 8 shown, the first electrode 802 and the second electrode 804 extend adjacent to each other in a generally circular coil. In some embodiments, and as Figure 9 shown, the first electrode 902 and the second electrode 904 extend adjacent to each other in a generally square or rectangular coil. In some embodiments, and as Figure 10 shown, the first electrode 1002 and the second electrode 1004 extend adjacent to each other in a generally octagonal coil. Figures 8 to 10 The first electrode and the second electrode in the arrangement shown may be radially spaced apart from each other and / or axially spaced apart.

[0046] Figure 11A and Figure 11B Another electrode arrangement for a substrate support according to the present case is shown. In some embodiments, and as Figure 11A shown, the first plurality of electrodes 1102 may be interdigitated with the second plurality of electrodes 1104, and the first plurality of electrodes and the second plurality of electrodes may extend parallel to each other in a horizontal direction. In some embodiments, and as Figure 11B shown, the first plurality of electrodes 1102 and the second plurality of electrodes 1104 may be interdigitated such that they extend parallel to each other in a horizontal direction, and the third plurality of electrodes 1106 and the fourth plurality of electrodes 1108 may be interdigitated such that they extend parallel to each other in a vertical direction. Thus, Figure 11B the electrodes are staggered in the embodiment shown. Interdigitated electrode arrangements such as Figure 11A and those shown in FIG. 11B may increase the retention time of static charges on a substrate support arranged according to an embodiment of the present case.

[0047] Figure 12Disclosed is a method of clamping a substrate using a substrate support according to an embodiment of the present case. In some embodiments, the method may begin at 1202 by placing the substrate on a support surface of the substrate support 100 (such as the contact area 108 of the table 106). Additionally, the method may include measuring the bow of the substrate at 1204. The bow may be measured in-situ after the substrate is placed on the substrate support, or measured off-line before the substrate is placed on the substrate support. In some embodiments, the substrate support 100 may be located in a processing chamber and may be part of a movable substrate pedestal accommodated in the processing chamber. Such a processing chamber may be used for a lithography process, a dielectric and conductor etching process, and a deposition process. In some embodiments, and as described in more detail below, the substrate support 100 may be separated from the processing chamber and used as a movable substrate carrier, as described in more detail below.

[0048] Additionally, the method may include determining, at 1206, the voltages to be applied to the plurality of electrodes 104 based on the measured bow of the substrate. For example, a first voltage to be applied to the first electrode 104a may be determined, and a second voltage to be applied to the second electrode 104b may be determined. As noted above, in some embodiments, the first voltage may be an AC voltage, and the second voltage may be an AC or DC voltage. In some embodiments, a voltage look-up table corresponding to the bow measurement results may be used to determine the voltages. In some embodiments, determining the DC voltage to be applied to the second electrode may also include determining an AC voltage to be superimposed on the DC voltage.

[0049] According to some embodiments, at 1208, the determined voltages may be applied to one or more of the plurality of electrodes 104. For example, the first voltage may be applied to the first electrode 104a, and the second voltage may be applied to the second electrode 104b. The voltages may be applied simultaneously or sequentially. In some embodiments, before starting substrate processing (such as etching or deposition) on the substrate, a verification may be made at 1210 as to whether the voltages are applied to all of the plurality of electrodes 104, and if not (No at 1210), further voltage determination and voltage application may occur until the voltages are applied to all of the plurality of electrodes 104. According to some embodiments, if the voltages are applied to all of the plurality of electrodes 104 (Yes at 1210), substrate processing may proceed at 1212. In some embodiments, and as Figure 12 shown, when the substrate processing is completed, the method may end at 1214.

[0050] Figure 13 Disclosed is an embodiment according to the present case including a modified Figure 12Method 1200 for clamping a substrate and method 1300. Specifically, in some embodiments, the method includes: measuring the substrate bow 1302 of the same substrate, determining the electrode voltage 1206, and applying a voltage 1208 to the electrodes if it is determined at 1304 that the bow is not optimized (No at 1304). Otherwise, in these embodiments, if it is determined that the bow is optimized (Yes at 1304), substrate processing can proceed at 1212. Additionally, in some embodiments, during substrate processing at 1212, the bow measurement results can be continuously or periodically checked to determine if the bow is optimized, and if not, the updated electrode voltage can be determined and applied to the electrodes to adjust the clamping force on the substrate.

[0051] In some embodiments, if at least one of the clamping pressure, substrate bow, or heat transfer flux is minimized, it can be determined that the wafer bow is optimized. In some embodiments, if the substrate bow is equal to or less than a predetermined substrate bow (such as the average substrate bow), the clamping pressure reaches or exceeds a predetermined clamping pressure (such as the average clamping pressure), or the heat transfer flux reaches or exceeds a predetermined heat transfer flux (such as the average heat transfer flux), then it can be determined that the wafer bow is optimized. As mentioned above, the substrate support embodiments according to the present case can be used as mobile carriers, and these mobile carriers can be used to carry substrates in multiple processing chambers, and these processing chambers can be part of a cluster tool. The substrate support according to the embodiments of the present case can be used as a mobile carrier by clamping the substrate to the substrate support according to the embodiments of the clamping method described herein and then moving the substrate and the carrier together after clamping. For example, in some embodiments, as Figure 14 shown, the bowed substrate 1402 can be placed on the substrate support 100. The placement of the substrate 1402 and the clamping of the substrate 1402 to the substrate support 100 can be performed inside or outside the processing chamber according to any embodiment of the clamping method described herein. In some embodiments, during clamping, the plurality of electrodes 104 can be connected to the exposed electrodes of the substrate support described above in connection with (for example) the substrate support 100 through (for example) the pin contacts of a voltage supplier to a voltage supplier. Once the substrate 1402 is clamped to the substrate support 100, the voltage supplier can be disconnected from the exposed electrodes through (for example) the pin contacts of the voltage supplier and stop applying voltage to the plurality of electrodes 104 and disconnect from the plurality of electrodes 104. Figure 15 Shows the substrate 1402 clamped to the substrate support 100 and disconnected from the voltage supplier.

[0052] After the electrode 104 is disconnected from the voltage supplier, due to the residual static charge existing between the substrate 1402 and the substrate support 100, the substrate 1402 can be held clamped to the substrate support 100. In some embodiments, based on the arrangement of the plurality of electrodes 104 in the substrate support 100, the residual static charge can have a lifespan of several hours to several days, such that the substrate 1402 is not unclamped from or released from the substrate support 100 for several hours to several days. In some embodiments, after the substrate 1402 is clamped to the substrate support 100, the substrate 1402 and the substrate support 100 can be moved together into a process chamber 1602 having an electrostatic chuck 1604, as Figure 16 shown. In some embodiments, and as Figure 16 shown, the substrate support 100 can be placed on the electrostatic chuck 1604 and electrostatically clamped to the electrostatic chuck 1604, thereby fixing the substrate 1402 and the substrate support 100 to the electrostatic chuck 1604. In some embodiments, the electrostatic chuck 1604 can include a plurality of pin contacts configured to contact the plurality of electrodes 104. Such pin contacts can be connected to a voltage supplier to apply an AC or DC voltage to the plurality of electrodes 104, thereby allowing adjustment of the clamping force on the substrate 1402 before and / or during substrate processing as described above. For example, in some embodiments, after the substrate 1402 and the substrate support 100 are transferred to the electrostatic chuck, an AC or DC voltage (such as a third voltage) can be applied to one of the electrodes in the plurality of electrodes 104 (such as the first electrode 104a), and an AC or DC voltage (such as a fourth voltage) can be applied to another one of the electrodes in the plurality of electrodes 104 (such as the second electrode 104b).

[0053] In some embodiments, after the substrate processing in the processing chamber 1602 is completed, the substrate support 1400 can be unclamped from the electrostatic chuck 1604, such that the substrate 1402 and the substrate support 100 can be transferred out of the processing chamber 1602 together. In some embodiments, if additional substrate processing is needed, the substrate 1402 and the substrate support 100 can be transferred to another processing chamber for additional substrate processing. Alternatively, in some embodiments, if no additional substrate processing is needed, the substrate 1402 can be unclamped from the substrate support 100, for example, by applying at least one of an ultraviolet (UV) flash to the substrate, applying a reverse voltage to the voltage applied to clamp the substrate, or thermally soaking the substrate at a higher temperature.

[0054] Figure 17 and Figure 18Disclosed is a substrate support 100 having table tops 106 of different heights according to an embodiment of the present case. In some embodiments, the height difference between the table tops 106 may be between 0.1 um and 2 mm. In some embodiments, and as Figure 17 shown, the table tops 106 may have a contact area 108 that commonly defines a convex support surface of the substrate support 100, and this contact area is adapted to support the concave surface 1702 of the substrate 1704. In some embodiments, and as Figure 18 shown, the table tops 106 may have a contact area 108 that commonly defines a concave support surface of the substrate support 100, and this contact area is adapted to support the convex surface 1802 of the substrate 1804.

[0055] In some embodiments, and as Figure 17 and Figure 18 shown, the substrate support 100 may include one or more electrodes 1706. For example, in some embodiments, Figure 17 and Figure 18 the substrate support 100 shown may include a plurality of electrodes 104 as described above. In some embodiments, the different heights of the table tops 106 may facilitate uniform contact between the contact areas 108 of the table tops 106 and the uneven or irregular rear surfaces of the substrates (such as substrates 1704 and 1804), thereby facilitating the concentration of surface charges on the substrates 1704 and 1804. Additionally, increasing the contact between the table tops 106 and the substrates 1704 and 1804 can promote heat transfer between the substrates 1704, 1804 and the substrate support 100. Furthermore, changing the height of the table tops 106 to more closely match the concave surface 1702 and the convex surface 1802 can reduce the voltage applied to the one or more electrodes 1706 and reduce the clamping force on the substrates 1704, 1804. This reduction in the clamping force can further reduce the friction (and the generation of undesirable particles) between the substrates 1704, 1804 and the substrate support 100.

[0056] In some embodiments, the plurality of table tops 106 may have the same cross-sectional shape and size. In some embodiments, the cross-sectional shape and size of the table tops 106 may be different. For example, in some embodiments, some of the plurality of table tops 106 may have a cylindrical, conical, frustoconical or annular cross-section. Additionally, in some embodiments, the radial spacing between the table tops 106 may be constant. In some embodiments, the radial spacing between one or more of the table tops 106 may be different.

[0057] In some embodiments, the height difference between the platen surfaces 106 may be fixed. For example, it may be observed that some substrates have a predictable or known bow or an irregular rear surface, and the irregular rear surface can be compensated for by a substrate support with a fixed platen surface having a height complementary to the profile of the irregular rear surface. In some embodiments, the height of the platen surfaces 106 may be adjustable to accommodate any irregular profile of the rear side of the substrate. For example, it may be observed that the substrate has random variations in the rear surface of the substrate, and the adjustability of the height of the platen surfaces 106 facilitates maximizing the contact between the platen surfaces 106 and the substrate. In some embodiments, the platen surfaces 106 may be adjusted independently axially, for example, by respective piezoelectric actuators connected to each platen surface 106. In some embodiments, the height of the platen surfaces 106 may be actively adjusted (i.e., using feedback control) based on measurements of electrostatic clamping force or substrate bow.

[0058] A method of controlling substrate bow of a substrate may include selectively depositing a material on at least a portion of the rear side of the substrate. In some embodiments, the material may include a polymer (such as Kapton) or an inorganic material (such as diamond material or diamond-like material). Such selective deposition may be beneficial for reducing substrate deformation by adding material to the substrate at selective locations on the substrate, thereby facilitating clamping the substrate using a lower clamping voltage. Additionally, in some embodiments, a subtraction process may be used to remove a certain excess of the deposited material. In some embodiments, the subtraction process may include etching. In some embodiments, the deposition may include lithography and inkjet printing. The rear side deposition may be performed under conditions of breaking vacuum or not breaking vacuum.

[0059] Figures 19 to 21 A method 1900 of controlling substrate bow according to an embodiment of the present disclosure is shown. In some embodiments, and as Figure 20 shown, at the start of the method, at 1902, a bowed substrate 2000 may be received, and at 1904, according to an embodiment of the present disclosure, the bowed substrate 2000 may be clamped to a substrate support 100. Additionally, in some embodiments, the substrate support 100 may include a plurality of heating elements configured to control the temperature in a plurality of heating zones of the substrate support.

[0060] In some embodiments, and as Figure 20As shown, in 1906, the back side 2002 can be coated with a coating 2006, which can be thermosensitive. In some embodiments, the coating 2006 can be applied by various methods, such as spraying, inkjet printing, or applying a preformed film to the back side of the substrate. The applied coating 2006 can initially have a uniform thickness. In some embodiments, the coating 2006 can be a statistically deterministic non-uniform coating and can be a film with different reactivity rates based on temperature. For example, this coating 2006 may elongate and thin when exposed to higher temperatures. In some embodiments, the coating 2006 can be made of insulating oxides, carbides, or nitrides (such as silicon oxide / silicon carbide / silicon nitride, aluminum oxide / aluminum carbide / aluminum nitride).

[0061] When clamping, the heating element can be set to different temperatures for a period of time to apply non-uniform temperatures to the substrate 2000 and the coating 2006 at 1908, such that different portions of the coating 2006 will react and thin at different rates. After heating the coating 2006 non-uniformly for a period of time, the coating 2006 will have a non-uniform thickness. At 1910, the substrate 2000 can be unclamped from the substrate support 2004, such that the coating 2006 strengthens the substrate 2000 to prevent the substrate 2000 from returning to a bowed configuration. The method can end at 1912.

[0062] Another method of controlling the bow of the substrate according to the present case can include selectively depositing a material on the substrate support surface of the electrostatic chuck to more closely conform to the profile of the back side of the substrate, so as to minimize the gap between the substrate support surface and the back side. The materials and methods for depositing and reducing materials described above for depositing on the substrate can also be used for depositing on the electrostatic chuck. In some embodiments, after the electrostatic chuck is used for substrate processing, any deposited material can be removed by a reduction method to prepare the electrostatic chuck for further substrate processing.

[0063] Figure 22 and Figure 23 Another embodiment of a substrate support 2200 for clamping a substrate is shown. The substrate support 2200 includes a plurality of pressure zones 2202 separated by a plurality of sealing bands 2204 configured to seal the back side surface of the substrate. These sealing bands can be O-rings. In some embodiments, and as Figure 22 shown, the sealing bands 2204 at discrete positions of the substrate support 2200 pixelate and define the plurality of pressure zones. These sealing bands 2204 may not be coaxially aligned. In some embodiments, and as Figure 21 shown, the plurality of pressure zones 2202 are annular and defined by coaxially aligned sealing bands 2204.

[0064] In some embodiments, the pressure in each pressure zone 2202 can be independently controlled to adjust the clamping force on a portion of the substrate sealed to each pressure zone 2202. In some embodiments, each pressure zone 2202 can have a separate vacuum opening 2206 in the substrate support 2200 that is connected to a vacuum source 2208. Additionally, in some embodiments, each pressure zone can have a gas supply opening 2210 for supplying a gas (such as helium) to each pressure zone. The gas flow can be used as a heat transfer medium for controlling the substrate temperature and the pressure control of each pressure zone 2202. Thus, in some embodiments, a gas can be introduced into the same pressure zone 2202 that is connected to the vacuum source. The pressure in each pressure zone 2202 can be adjusted by regulating at least one of the vacuum source and / or the gas flow.

[0065] In use, the substrate can be clamped to the substrate support by placing the back side of the substrate above the substrate support 2200 and in contact with the plurality of sealing bands 2204. The substrate bow can be measured, and the pressure in each pressure zone 2202 can be adjusted to adjust the substrate bow. For example, in some embodiments, the pressure in the pressure zone 2202 can be controlled to minimize the wafer bow of the substrate.

[0066] Although the above is directed to embodiments of the present case, other embodiments and additional embodiments of the present case can be designed without departing from the basic scope of the present case.

Claims

1. A method for clamping a substrate, the method comprising: i. placing the substrate on a clamping surface of a substrate support having a plurality of electrodes spaced apart from each other including a first electrode and a second electrode; ii. measuring the substrate bow of the substrate; iii. determining a first voltage to be applied to the first electrode and a second voltage to be applied to the second electrode based on the measured substrate bow, wherein the first voltage is an AC voltage and the second voltage is an AC or DC voltage; and iv. applying the first voltage to the first electrode and the second voltage to the second electrode to clamp the substrate to the substrate support.

2. The method of claim 1, the method further comprising: repeating ii, iii, and iv until it is determined that the substrate bow of the substrate is optimized.

3. The method of claim 1 or claim 2, the method further comprising: applying a non-uniform coating to the substrate while clamping the substrate to the substrate support.

4. The method of claim 1 or claim 2, wherein the first voltage and the second voltage are applied sequentially.

5. The method of claim 1 or claim 2, wherein the first voltage and the second voltage are applied simultaneously.

6. The method of claim 1, the method further comprising: stopping applying the first voltage to the first electrode and the second voltage to the second electrode; transferring the clamped substrate and the substrate support together to a processing chamber having an electrostatic chuck, and electrostatically coupling the substrate support to the electrostatic chuck; and after the transfer, applying a third voltage to the first electrode and a fourth voltage to the second electrode, wherein the third voltage is an AC or DC voltage and the fourth voltage is an AC or DC voltage.

7. The method of claim 1 or claim 2, wherein the second voltage is an AC voltage.

8. The method according to claim 1 or claim 2, wherein applying the second voltage to the second electrode comprises: Applying a DC voltage and an AC voltage to the second electrode simultaneously.

9. A system for clamping a substrate, the system comprising: a substrate support having a surface for supporting a substrate; a plurality of electrodes spaced apart from each other in or on the substrate support, the plurality of electrodes including a first electrode and a second electrode; and a controller configured to receive a measurement result of the substrate bow of the substrate, and determine a first voltage to be applied to the first electrode and a second voltage to be applied to the second electrode based on the substrate bow, and apply the first voltage to the first electrode and the second voltage to the second electrode, wherein the first voltage is an AC voltage and the second voltage is an AC or DC voltage.

10. The system of claim 9, wherein the controller is configured to optimize the substrate bow of the substrate by repeatedly receiving a measurement result of the substrate bow, determining the first voltage and the second voltage, and re-applying the first voltage and the second voltage based on the received measurement result of the substrate bow.

11. The system of claim 9 or claim 10, wherein the plurality of electrodes are interdigitated.

12. The system of claim 9 or claim 10, wherein the controller is configured to apply the first voltage and the second voltage sequentially.

13. The system of claim 9 or claim 10, wherein the controller is configured to apply the first voltage and the second voltage simultaneously.

14. The system of claim 9, the system further comprising an electrostatic chuck, wherein the substrate support is configured to be removably coupled to the electrostatic chuck.

15. The system of claim 9 or claim 10, wherein the second voltage is an AC voltage.

16. The system of claim 9 or claim 10, wherein the controller is configured to apply a DC voltage and an AC voltage to the second electrode simultaneously.

17. A non-transitory computer-readable storage medium storing instructions that, when executed by a processor of a system for holding a substrate of a substrate support having a plurality of electrodes spaced apart from each other including a first electrode and a second electrode, perform a method of holding the substrate including the steps of: i. placing the substrate on a holding surface of a substrate support having a plurality of spaced electrodes including a first electrode and a second electrode; ii. measuring the substrate bow of the substrate; iii. determining a first voltage to be applied to the first electrode and a second voltage to be applied to the second electrode based on the measured substrate bow, wherein the first voltage is an AC voltage and the second voltage is an AC or DC voltage; and iv. applying the first voltage to the first electrode and applying the second voltage to the second electrode.

18. The non-transitory computer-readable storage medium of claim 17, wherein the method further comprises: repeating ii, iii, and iv until it is determined that the substrate bow of the substrate is optimized.

19. The non-transitory computer-readable storage medium of claim 17 or claim 18, wherein the second voltage is an AC voltage.

20. The non-transitory computer-readable storage medium of claim 17 or claim 18, wherein applying the second voltage to the second electrode comprises: Applying a DC voltage and an AC voltage to the second electrode simultaneously.

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