Water vapor plasma for increasing the hydrophilicity of surfaces

Abstract

A method and apparatus for treating a substrate is provided herein. For example, a method for increasing surface hydrophilicity on a substrate includes: a) using a remote plasma source to provide water vapor plasma to a treatment region of a plasma treatment chamber to treat a bonding surface of the substrate; b) providing at least one of microwave power or RF power to the plasma treatment chamber at a frequency of about 1 kHz to 10 GHz and a power of about 1 kW to 10 kW to maintain the water vapor plasma in the treatment region during the process; and c) continuing a) and b) until the hydrophilic contact angle of the bonding surface of the substrate is less than 10°.

Description

[Technical Field]

[0001]

[0001] Embodiments of the present disclosure generally relate to methods and apparatus for processing substrates. More particularly, embodiments of the present disclosure relate to methods and apparatus for increasing surface hydrophilicity for substrate-level packaging using water vapor plasma. [Background technology]

[0002]

[0002] Back-end (BEOL) packaging processes are known. For example, BEOL packaging processes typically use one or more bonding processes to bond substrates together. For example, some methods and apparatuses use one or more gas chemicals (e.g., argon (Ar), nitrogen (N2), and / or oxygen (O2)) that can be supplied to the interior of a plasma chamber, a capacitively coupled RF source can be used to form a capacitively coupled plasma, and dry and wet processes can be used to treat the surfaces of the substrates to promote bonding during the BEOL packaging process. However, such processes can often fail to provide the required bond strength (e.g., 1 J / m 2 However, the adequate hydrophilic surface (e.g., contact angle less than 10°) required to achieve a contact angle greater than 10° is not obtained. Summary of the Invention

[0003]

[0003] Provided herein are methods and apparatus for treating a substrate. In some embodiments, a method for increasing surface hydrophilicity on a substrate includes: a) supplying a water vapor plasma to a processing region of a plasma processing chamber using a remote plasma source to treat a bonding surface of the substrate; b) supplying at least one of microwave power or RF power to the plasma processing chamber at a frequency of about 1 kHz to 10 GHz and a power of about 1 kW to 10 kW to maintain the water vapor plasma in the processing region during the process; and c) continuing a) and b) until a hydrophilic contact angle of the bonding surface of the substrate is less than 10°.

[0004]

[0004] According to at least some embodiments, a non-transitory computer-readable storage medium has stored thereon instructions that, when executed by a processor, perform a method for increasing surface hydrophilicity on a substrate, including: a) supplying water vapor plasma to a processing region of a plasma processing chamber using a remote plasma source to process the bonding surface of the substrate; b) supplying at least one of microwave power or RF power to the plasma processing chamber at a frequency of about 1 kHz to 10 GHz and at a power of about 1 kW to 10 kW to maintain the water vapor plasma in the processing region during the process; and c) continuing a) and b) until the hydrophilic contact angle of the bonding surface of the substrate is less than 10°.

[0005]

[0005] According to at least some embodiments, a system for increasing surface hydrophilicity on a substrate includes a remote plasma source connected to the plasma processing chamber for supplying water vapor plasma to a processing region of the plasma processing chamber to process a bonding surface of the substrate, and at least one of a microwave power source or an RF power source connected to the processing region and configured to supply microwave power or RF power to the plasma processing chamber at a frequency of about 1 kHz to 10 GHz and a power of about 1 kW to 10 kW to maintain the water vapor plasma in the processing region during the process, wherein the remote plasma source and at least one of the microwave power source or the RF power source are operable until the hydrophilic contact angle of the bonding surface of the substrate is less than 10°.

[0006]

[0006] Other further embodiments of the present disclosure are described below.

[0007]

[0007] The embodiments of the present disclosure summarized above and described in more detail below can be understood by reference to the exemplary embodiments of the present disclosure illustrated in the accompanying drawings. However, the accompanying drawings depict only typical embodiments of the present disclosure and therefore should not be considered limiting in scope, as the present disclosure may admit of other equally effective embodiments. [Brief explanation of the drawings]

[0008] [Figure 1]FIG. 1 illustrates a partial cross-sectional view of a vacuum processing chamber in accordance with at least some embodiments of the present disclosure. [Figure 2] FIG. 2 is a flow diagram of a method for processing a substrate using the vacuum processing apparatus of FIG. 1 in accordance with at least some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009]

[0010] To facilitate understanding, the same reference numerals have been used, wherever possible, to designate identical elements common to the drawings. The drawings are not drawn to scale and may be simplified for clarity. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0010]

[0011] Embodiments for processing substrates are provided herein. For example, methods and apparatus may include a plasma system configured to supply a water vapor gas chemistry (water vapor plasma), which may be combined with other gases (e.g., argon (Ar), nitrogen (N), oxygen (O), and / or ozone (O)). For example, the plasma system may include a remote plasma source configured to supply the water vapor plasma and an RF or microwave generator configured to supply microwave or RF power to the plasma processing chamber at a frequency of about 1 kHz to 10 GHz and a power of about 1 kW to 10 kW to maintain the water vapor plasma in the processing region during the process, for example, until the hydrophilic contact angle of the substrate's bonding surface is less than 10°. According to the present disclosure, water vapor plasma provides the dual benefits of increasing surface hydrophilicity while simultaneously cleaning the surface of organic contaminants. These dual benefits are achieved without the need to compromise dielectric thickness, which can affect the performance of, for example, bonding copper (Cu) pad dishes. Additionally, the use of microwave plasma increases plasma density to ensure complete surface treatment, and the remote plasma configuration can generate a gentle plasma that minimizes surface damage and / or roughening.

[0011]

[0012] FIG. 1 is a schematic cross-sectional view of a processing chamber 100 for processing substrates according to at least some embodiments of the present disclosure. The substrates can be composed of various types, such as, but not limited to, standard silicon wafers, diced wafers on a tape frame, or bonded wafers. Examples of processing chambers suitable for incorporating the apparatus described herein include physical vapor deposition (PVD) chambers, chemical vapor deposition (CVD) chambers, etch chambers, and the like, all of which are available from Applied Materials, Inc., Santa Clara, California. The following processing chamber descriptions are provided for background and illustrative purposes and should not be construed as limiting the scope of the present disclosure. For illustrative purposes, processing chamber 100 is described herein as a CVD chamber that can also perform etch or cleaning processes.

[0012]

[0013] The processing chamber 100 includes a chamber body 102, a lid assembly 104, and a support assembly 106. The lid assembly 104 is positioned on top of the chamber body 102. The support assembly 106 is disposed in an interior region 108 (processing region) defined by the chamber body 102. The chamber body 102 includes a slit valve opening 110 formed in a sidewall thereof. The slit valve opening 110 is selectively opened and closed to allow access to the interior region 108 by a substrate handling robot (not shown) for substrate transfer.

[0013]

[0014] The chamber body 102 may further include a liner 112 that surrounds the support assembly 106. The liner 112 may be made of a metal such as (Al), a ceramic material, or any other process-compatible material. In one or more embodiments, the liner 112 includes one or more apertures 114 and a pumping channel 116 formed therein that is fluidly connected to a vacuum port 118. The apertures 114 provide a flow path for gases into the pumping channel 116. The pumping channel 116 provides an outlet for gases within the processing chamber 100 to the vacuum port 118.

[0014]

[0015] Pressure system 120 may be configured to maintain a desired pressure (e.g., 1 mTorr to about 1 Torr) within processing chamber 100 and is configured to evacuate (e.g., pump down) interior region 108 of processing chamber 100. For example, in at least some embodiments, vacuum port 118 may be coupled to pump 122 via valve 124 to evacuate interior region 108 of processing chamber 100 and maintain a desired pressure within processing chamber 100, e.g., to maintain a relatively high pressure during a cleaning process and a relatively low pressure (e.g., vacuum) during substrate processing, or vice versa.

[0015]

[0016] The lid assembly 104 includes at least two laminated components configured to form a plasma region or cavity therebetween. In one or more embodiments, the lid assembly 104 includes a first electrode ("top electrode") 126 vertically disposed above a second electrode ("bottom electrode") 128. The first electrode 126 and the second electrode 128 confine a plasma cavity 130 therebetween. The first electrode 126 is connected to a power source, such as an RF power source 132. The second electrode 128 is connected to ground, forming a capacitor between the first electrode 126 and the second electrode 128 (e.g., a capacitively coupled plasma (CCP)). The first electrode 126 is in fluid communication with a gas inlet 134 connected to a gas source 135 that supplies a process gas (e.g., argon (Ar), hydrogen (H), nitrogen (N), oxygen (O), or ozone (O)) to the processing chamber 100 via the gas inlet 134, which can be energized to generate activated process gas (e.g., ionized plasma or radicals) to perform one or more processes (e.g., deposition process, etching process, cleaning process, etc.). A first end of the one or more gas inlets 134 opens into the plasma cavity 130.

[0016]

[0017] Alternatively or additionally, the processing chamber 100 may include one or more coils (e.g., an inductively coupled plasma (ICP) configuration) that may be used to apply a voltage to one or more process gases to generate an activated process gas.

[0017]

[0018] Alternatively or additionally, a microwave power supply 141 may be connected to the processing chamber 100 and used to apply a voltage to one or more process gases to generate activated process gases, as described in more detail below.

[0018]

[0019] Alternatively or additionally, the gas source 135 may be coupled to a remote plasma source 137 configured to supply plasma or radicals to the plasma cavity 130 of the processing chamber 100, depending on the configuration of the remote plasma source. For example, in at least some embodiments, the remote plasma source 137 may be connected to a water source 133 and configured to supply water vapor plasma to the processing region (e.g., interior region 108) for processing a bonding surface (not shown) of a substrate (e.g., substrate 101). In at least some embodiments, the water source 133 may be configured to supply water (e.g., deionized water) during processing, as described in more detail below.

[0019]

[0020] The lid assembly 104 may also include an isolator ring 136 that electrically insulates the first electrode 126 from the second electrode 128. The isolator ring 136 may be made of aluminum oxide (AlO) or any other insulating, process-compatible material.

[0020]

[0021] The lid assembly 104 may also include a showerhead 150 and an optional blocker plate 140. The showerhead 150 includes a gas distribution plate 138, a backing (gas) plate 139, and a cooling plate 151. The second electrode 128, the gas distribution plate 138, the cooling plate 151, and the blocker plate 140 may be stacked on a lid rim 142 that may be coupled to the chamber body 102 and function as a temperature control ring, as described in more detail below.

[0021]

[0022] The cooling plate 151 is configured to regulate the temperature of the gas distribution plate 138 during processing. For example, the cooling plate 151 may include one or more temperature control channels (not shown) formed therethrough such that a temperature control fluid may be supplied therein to regulate the temperature of the gas distribution plate 138.

[0022]

[0023] The second electrode 128 may include a plurality of gas passages 144 formed below the plasma cavity 130 to allow gas from the plasma cavity 130 to flow therethrough. The backing gas plate 139 may include one or more gas passages (not shown) and one or more gas supply channels (not shown), thus allowing gas to flow from the one or more gas passages into the processing region. Similarly, the gas distribution plate 138 includes a plurality of apertures 146 configured to distribute the flow of gas therethrough. A blocker plate 140 may optionally be disposed between the second electrode 128 and the gas distribution plate 138. The blocker plate 140 includes a plurality of apertures 148 to provide a plurality of gas passages from the second electrode 128 to the gas distribution plate 138.

[0023]

[0024] The support assembly 106 may include a support member 180 (e.g., a substrate support). The support member 180 is configured to support a substrate 101 (e.g., an epoxy substrate, a glass substrate, a silicon substrate, a diced substrate on a tape frame, or a bonded substrate) for processing. The support member 180 may be coupled to a lift mechanism 182 through a shaft 184 extending through the bottom surface of the chamber body 102. The lift mechanism 182 may be flexibly sealed to the chamber body 102 by a bellows 186 that prevents vacuum leakage around the shaft 184. The lift mechanism 182 enables the support member 180 to be vertically moved between a lower transfer portion and multiple elevated process positions within the chamber body 102. For example, in at least some embodiments, the lift mechanism 182 is configured to position a substrate support surface 187 of the support member 180 from a substrate processing position a first distance away from the showerhead 150 to a cleaning position, e.g., a second distance away from the showerhead 150, the second distance being less than the first distance. Additionally, one or more lift pins 188 may be disposed through the support member 180 and coupled to a bottom surface of the substrate support surface 187. The one or more lift pins 188 are configured to extend through the support member 180 such that the substrate 101 may be lifted off the surface of the support member 180. The one or more lift pins 188 may be actuated by a lift ring 190.

[0024]

[0025] A heater 181 (e.g., one or more heating electrodes) may be provided on the support assembly 106 and may be configured to heat the support assembly 106 (e.g., to heat the substrate 101 during processing thereof and / or during a cleaning process of the showerhead 150). The heater 181 is coupled to a DC power source 131 to heat the support assembly 106 to a predetermined temperature, e.g., to heat the substrate 101 and / or the showerhead 150.

[0025]

[0026] The processing chamber may also include a controller 191. The controller 191 includes a central processing unit 192 (programmable) operable with a memory 194 and mass storage device, an input control unit, and a display unit (not shown), such as power supplies, clocks, cache, input / output (I / O) circuits, and liner 112, coupled to various components of the processing system to facilitate control of substrate processing.

[0026]

[0027] To facilitate control of the process chamber 100 as described above, a central processing unit 192 may be one of any form of general-purpose computer processor that can be used in an industrial environment, such as a programmable logic controller (PLC), for controlling the various chambers and sub-processors. A memory 194 is coupled to the central processing unit 192 and may be a non-transitory computer-readable storage medium, such as one or more of readily available memory, such as random access memory (RAM), read-only memory (ROM), a floppy disk drive, a hard disk, or any other form of digital storage, local or remote. Support circuits 196 are coupled to the central processing unit 192 to support the processor in a conventional manner. Charged species generation, heating, and other processes are generally stored in the memory 194, typically as software routines. The software routines may also be stored and / or executed by a second central processing unit (not shown) located remotely from the process chamber 100 controlled by the central processing unit 192.

[0027]

[0028] The memory 194 is in the form of a computer-readable storage medium containing instructions that, when executed by the central processing unit 192, facilitate operation of the process chamber 100. The instructions in the memory 194 are in the form of a program product, such as a program that performs the methods of the present disclosure. The program code may be in any one of a number of different programming languages. In one example, the present disclosure may be implemented as a program product stored on a computer-readable storage medium for use with a computer system. The program(s) in the program product define the functions of the embodiments (including the methods described herein). Exemplary computer-readable storage media may include, but are not limited to, (i) a non-writable storage medium on which information is permanently stored (e.g., a read-only memory device in a computer, such as a CD-ROM disk readable by a CD-ROM drive, a flash memory, a ROM chip, or any type of solid-state non-volatile semiconductor memory), and (ii) a writable storage medium on which changeable information is stored (e.g., a floppy disk in a diskette drive or hard disk drive, or any type of solid-state random-access semiconductor memory). Such non-transitory computer-readable storage media, when carrying computer-readable instructions that direct the functions of the methods described herein, are embodiments of the present disclosure.

[0028]

[0029] 2 is a flow diagram of a method 200 for processing a substrate (e.g., a substrate 101, which may be an epoxy substrate, a glass substrate, a silicon substrate, a dicing substrate on a tape frame, or a bonding substrate) using the processing chamber 100 of FIG. 1 in accordance with at least some embodiments of the present disclosure. For example, after the substrate is processed (e.g., a deposition process), the substrate may need to be prepared (cleaned / etched) for substrate packaging (e.g., a bonding process). As mentioned above, to facilitate achieving high bond strength, the bonding surfaces of the substrates need to be hydrophilic and clean (e.g., remove organic / inorganic contaminants, etc.).

[0029]

[0030] Thus, the method 200 may be directed to increasing surface hydrophilicity on a substrate. For example, at 202, the method 200 may include supplying water vapor plasma to a processing region of a plasma processing chamber using a remote plasma source to treat a bonding surface of the substrate. For example, at 202, the remote plasma source 137 may supply water vapor plasma to the interior region 108 of the processing chamber 100.

[0030]

[0031] Next, at 204, the method 200 includes supplying at least one of microwave power or RF power to the plasma processing chamber at a frequency of about 1 kHz to 10 GHz and a power of about 1 kW to 10 kW to maintain a water vapor plasma in the processing region during the process. For example, the RF power source 132 may be used to maintain the water vapor plasma in the processing chamber 100. In at least some embodiments, the RF power may be supplied at a frequency of about 1 kHz to 10 MHz. Alternatively or additionally, a microwave power source 141 may be used to maintain the water vapor plasma in the processing chamber 100. In at least some embodiments, the microwave power may be supplied at a frequency of about 1 GHz to about 10 GHz. In at least some embodiments, the microwave power and / or the RF power may be supplied using a pulsed or continuous wave. Furthermore, in at least some embodiments, the inventors have found that a suitable plasma source-to-substrate distance may be about 2 cm to about 15 cm. Furthermore, in at least some embodiments, the pressure in the processing region may be about 1 mTorr to about 1 Torr.

[0031]

[0032] Next, at 206, the method includes continuing 202 and 204 until the hydrophilic contact angle of the bonding surface of the substrate is less than 10°. For example, in at least some embodiments, the substrate may be treated for about 0.1 seconds to about 30 minutes. For example, in at least some embodiments, the substrate may be treated for about 0.1 seconds to about 10 minutes.

[0032]

[0033] In at least some embodiments, the method 200 optionally includes supplying at least one of argon (Ar), hydrogen (H), nitrogen (N), oxygen (O), or ozone (O) to the processing region while supplying the water vapor plasma. In such embodiments, the at least one of argon (Ar), hydrogen (H), nitrogen (N), and oxygen (O) may be supplied at a flow rate of up to about 5000 sccm, and the ozone (O) may be supplied at a flow rate of up to about 10 slpm, with a density of about 0 to about 300 g / m. 3 has a concentration of

[0033]

[0034] In at least some embodiments, when ozone (O3) is used, it may prove advantageous to supply the ozone (O3) at the flow rate and concentration described above to treat the bonding surface of the substrate for about 0.1 seconds to about 30 minutes. Furthermore, when ozone (O3) is used to treat the bonding surface of the substrate, method 200 includes supplying deionized water to interior region 108 before, after, or simultaneously with the ozone (O3) to coat the bonding surface of the substrate. In at least some embodiments, method 200 includes supplying the deionized water at a flow rate of about 0.1 ml / min to about 100 ml / min. Furthermore, in at least some embodiments, method 200 includes supplying the deionized water at a temperature of about 0° C. to about 100° C. Furthermore, in at least some embodiments, method 200 includes rotating the substrate at a speed of greater than 0 rpm to about 150 rpm.

[0034]

[0035] In at least some embodiments, when using ozone (O), it may prove advantageous to treat the bonding surface of the substrate without the use of a water vapor plasma and an RF or microwave source (e.g., no vacuum-based plasma environment is required).

[0035]

[0036] In at least some embodiments, deionized water can be used, and the substrate can be rotated as described above during any of steps 202-206, with or without supplying any of the aforementioned process gases.

[0036]

[0037] While the forgoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof.

Claims

1. 1. A method for increasing surface hydrophilicity on a substrate, comprising: a) providing a water vapor plasma to a processing region of a plasma processing chamber using a remote plasma source to process a bonding surface of the substrate; b) supplying at least one of microwave power and RF power to the plasma processing chamber at a frequency of about 1 kHz to 10 GHz and a power of about 1 kW to 10 kW to maintain the water vapor plasma in the processing region during operation; c) continuing a) and b) until the hydrophilic contact angle of the bonding surface of the substrate is less than 10°; A method comprising:

2. The method of claim 1 , wherein the RF power is supplied at a frequency of about 1 kHz to about 10 MHz.

3. The method of claim 1 , wherein the microwave power is provided at a frequency of about 1 GHz to about 10 GHz.

4. 10. The method of claim 1, wherein the pressure in the processing region is from about 1 mTorr to about 1 Torr.

5. The method of claim 1 , wherein the substrate is treated for about 0.1 seconds to about 10 minutes.

6. The method of claim 1 , wherein at least one of the microwave power or the RF power is supplied using a pulsed wave.

7. The method of claim 1 , wherein at least one of the microwave power or the RF power is supplied using a continuous wave.

8. While supplying the water vapor plasma, argon (Ar) and hydrogen (H ２ ), nitrogen (N ２ ), oxygen (O ２ ) or ozone (O ３ 10. The method of claim 1, further comprising providing at least one of:

9. Argon (Ar), hydrogen (H ２ ), nitrogen (N ２ ), oxygen (O ２ ) is supplied at a flow rate of up to about 5000 sccm, and ozone (O ３ 9. The method of claim 1, wherein the suction pressure is 100 psi or less.

10. The method of claim 1 , wherein the substrate is treated for about 0.1 seconds to about 30 minutes.

11. Ozone (O ３ ) is from about 0 to about 300 g / m ３ 9. The method of claim 1, wherein the concentration of

12. The method of claim 8 , further comprising supplying deionized water to the surface of the substrate at a flow rate of about 0.1 ml / min to about 500 ml / min.

13. 13. The method of claim 12, further comprising providing the deionized water at a temperature of about 0°C to about 100°C.

14. 14. The method of any one of claims 1 to 8, 12 and 13, further comprising rotating the substrate at a speed of greater than 0 rpm to about 150 rpm.

15. 1. A non-transitory computer-readable storage medium having stored thereon instructions that, when executed by a processor, perform a method for increasing surface hydrophilicity on a substrate, the method comprising: a) providing a water vapor plasma to a processing region of a plasma processing chamber using a remote plasma source to process a bonding surface of the substrate; b) supplying at least one of microwave power and RF power to the plasma processing chamber at a frequency of about 1 kHz to 10 GHz and a power of about 1 kW to 10 kW to maintain the water vapor plasma in the processing region during operation; c) continuing a) and b) until the hydrophilic contact angle of the bonding surface of the substrate is less than 10°; 1. A non-transitory computer-readable storage medium comprising:

16. the RF power is supplied at a frequency of about 1 kHz to about 10 MHz; 16. The non-transitory computer-readable storage medium of claim 15, wherein the microwave power is supplied at a frequency of about 1 GHz to about 10 GHz.

17. 16. The non-transitory computer-readable storage medium of claim 15, wherein the pressure in the processing region is from about 1 mTorr to about 1 Torr.

18. 16. The non-transitory computer-readable storage medium of claim 15, wherein the substrate is processed for about 0.1 seconds to about 10 minutes.

19. 19. The non-transitory computer-readable storage medium of claim 15, wherein at least one of the microwave power and the RF power is supplied using a pulsed wave.

20. 1. A system for increasing surface hydrophilicity on a substrate, comprising: a remote plasma source connected to the plasma processing chamber for delivering a water vapor plasma into a processing region of the plasma processing chamber to process the bonding surface of the substrate; at least one of a microwave power source or an RF power source connected to the processing region and configured to supply microwave power or RF power to the plasma processing chamber at a frequency of about 1 kHz to 10 GHz and a power of about 1 kW to 10 kW to maintain the water vapor plasma in the processing region during operation; Equipped with The system, wherein the remote plasma source and at least one of the microwave power source or the RF power source are operable until a hydrophilic contact angle of the bonding surface of the substrate is less than 10°.

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