Method for increasing the service life of electrostatic chucks and readable storage medium

Abstract

The present application relates to the technical field of semiconductor manufacturing, and particularly relates to a method for prolonging the service life of an electrostatic chuck and a readable storage medium, which comprises the following steps: optimizing the wafer running scheme of a machine table through dispatch control, dividing wafers into a first wafer group and a second wafer group according to different types, and making the ion implantation processes of the first wafer group and the second wafer group alternately proceed; grabbing the wafer to be processed by a mechanical hand and placing the wafer on an electrostatic chuck of an ion implantation machine table to perform electrostatic adsorption; when the wafer to be processed is a wafer in the first wafer group, adjusting the electrostatic neutralization and beam control device from an open state to a closed state; when the wafer to be processed is a wafer in the second wafer group, adjusting the electrostatic neutralization and beam control device from the closed state to the open state. Through the dispatch control of the machine table, the wafer running scheme is optimized, and the problem of adsorption electrode material aging caused by the accumulation of residual charges due to the long-term closing of the electrostatic neutralization and beam control device can be avoided.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a method for improving the service life of electrostatic chucks and a readable storage medium. Background Technology

[0002] In recent years, image sensors (CMOS) have been widely used in mobile imaging, digital still and video cameras, internet-based video conferencing, surveillance, and biometrics. Due to their unique operating performance, CMOS image sensors have special process requirements in current advanced semiconductor manufacturing processes. The completion of these processes typically involves placing the wafer on a chuck within the reaction chamber of semiconductor processing equipment for wafer processing. The chuck serves to support and fix the wafer. An electrostatic chuck is a chuck structure that uses electrostatic force to fix the wafer, eliminating the disadvantages of traditional mechanical chucks, such as complex structures and reduced effective wafer processing area.

[0003] An electrostatic chuck uses electrostatic attraction to hold a wafer on a chuck, reducing chipping, increasing the effective processing area, and minimizing the deposition of corrosion particles on the wafer surface. An electrostatic chuck typically consists of a chuck, a DC power supply, and adsorption electrodes. The chuck supports and holds the wafer, while the DC power supply is electrically connected to the adsorption electrodes embedded within the chuck, providing power to them. During the process, the robot places the wafer on the chuck's support surface. The DC power supply applies a DC voltage to the adsorption electrodes, inducing static charge on the wafer surface. This static charge creates an electrostatic attraction between the wafer and the adsorption electrodes, securing the wafer to the chuck's support surface. After the process is complete, the DC power supply is turned off, and the static charge on the wafer surface is released through a grounding pin to dissipate static electricity and eliminate the electrostatic attraction.

[0004] During ion implantation, a power field neutralization (PFG) device is typically used to provide electrons to neutralize the charge of the ion beam. However, because the PFG is made of metallic materials, it is turned off when working in the imaging area of ​​a CMOS image sensor to reduce metal contamination. Under ultra-high energy, long-term operation with the PFG off, the ability of the adsorption electrodes on the surface of the electrostatic chuck to release charge decreases. The accumulation of residual charge easily causes aging of the adsorption electrode material, thereby accelerating the reduction of the electrostatic chuck's lifespan, resulting in long replacement cycles and high costs. Summary of the Invention

[0005] The purpose of this invention is to provide a method for improving the service life of electrostatic chucks and a readable storage medium, which solves the problem of residual charge accumulation causing aging of adsorption electrode materials under the condition of PFG shutdown during ultra-high energy long-term operation in the prior art.

[0006] To achieve the above objectives, the present invention provides a method for improving the service life of an electrostatic chuck, comprising:

[0007] The wafer delivery plan is optimized by dispatching control equipment. The wafers are divided into a first wafer group and a second wafer group according to different types, and the ion implantation process of the first wafer group and the second wafer group is carried out alternately.

[0008] The wafer is picked up by a robotic arm and placed on an electrostatic chuck of an ion implantation machine.

[0009] The wafer is electrostatically adsorbed by the electrostatic chuck for ion implantation.

[0010] When the wafer to be processed is a wafer in the first wafer group, the electrostatic neutralization and beam control device is adjusted from the on state to the off state; when the wafer to be processed is a wafer in the second wafer group, the electrostatic neutralization and beam control device is adjusted from the off state to the on state.

[0011] Optionally, the DC voltage applied to the adsorption electrode of the electrostatic chuck is adjusted to an optimal value before ion implantation of the wafer.

[0012] Optionally, the optimal value of the DC voltage applied to the adsorption electrode of the electrostatic chuck is 800V.

[0013] Optionally, the gripping speed of the robotic arm is adjusted to an optimal value before ion implantation of the wafer.

[0014] Optionally, the optimal gripping rate of the robotic arm is 30%.

[0015] Optionally, before ion implantation of the wafer, the ionization gas flow rate of the electrostatic neutralization and beam control device is adjusted to an optimal value.

[0016] Optionally, the optimal value for the ionized gas flow rate of the electrostatic neutralization and beam control device is 12 Torr.

[0017] Optionally, the ionization voltage of the electrostatic neutralization and beam control device is adjusted to an optimal value before ion implantation of the wafer.

[0018] Optionally, the optimal value of the ionization voltage of the electrostatic neutralization and beam control device is 5V.

[0019] Based on the same technical concept, the present invention also provides a readable storage medium, wherein when the computer program is executed, it can implement the method for improving the service life of the electrostatic chuck as described above.

[0020] In the method and readable storage medium for improving the service life of electrostatic chucks provided by the present invention, the wafer routing scheme is optimized by dispatching control equipment, so that wafers that do not require the electrostatic neutralization and beam control devices to be turned on during ion implantation and wafers that do require the electrostatic neutralization and beam control devices to be turned on are alternately operated. This can avoid the problem of residual charge accumulation caused by the long-term shutdown of the electrostatic neutralization and beam control devices, which leads to the aging of the adsorption electrode material of the electrostatic chuck, thereby improving the service life of the electrostatic chuck. Attached Figure Description

[0021] Those skilled in the art will understand that the accompanying drawings are provided to better understand the invention and do not constitute any limitation on the scope of the invention. Wherein:

[0022] Figure 1 This is a step diagram illustrating a method for improving the service life of an electrostatic chuck according to an embodiment of the present invention. Detailed Implementation

[0023] To make the objectives, advantages, and features of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clearly illustrate the purpose of the embodiments of this invention. Please refer to the accompanying drawings to make the objectives, features, and advantages of this invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only used to complement the content disclosed in the specification, for those skilled in the art to understand and read, and are not intended to limit the implementation conditions of this invention. Any modifications to the structure, changes in proportions, or adjustments to the size, if they are the same as or similar to the effects and objectives achieved by this invention, should still fall within the scope of the technical content disclosed in this invention.

[0024] As used herein, the singular forms “a,” “an,” and “the” include plural objects unless otherwise expressly indicated. As used herein, the term “or” is generally used to include “and / or” unless otherwise expressly indicated. As used herein, the term “a number” is generally used to include “at least one” unless otherwise expressly indicated. As used herein, the term “at least two” is generally used to include “two or more” unless otherwise expressly indicated. Furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as “first,” “second,” or “third” may explicitly or implicitly include one or at least two of that feature.

[0025] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] Please refer to Figure 1 , Figure 1 This is a flowchart illustrating the steps of a method for improving the service life of an electrostatic chuck according to an embodiment of the present invention. This embodiment provides a method for improving the service life of an electrostatic chuck, including:

[0027] S1. Optimize the wafer delivery plan by dispatching control equipment, divide the wafers into a first wafer group and a second wafer group according to different types, and alternate the ion implantation process of the first wafer group and the second wafer group.

[0028] S2. The wafer is picked up by a robotic arm and placed on an electrostatic chuck of an ion implantation machine.

[0029] S3. The wafer is electrostatically adsorbed by the electrostatic chuck in order to perform ion implantation process;

[0030] S4. When the wafer to be processed is a wafer in the first wafer group, the electrostatic neutralization and beam control device is adjusted from the on state to the off state; when the wafer to be processed is a wafer in the second wafer group, the electrostatic neutralization and beam control device is adjusted from the off state to the on state.

[0031] By optimizing the wafer delivery process through dispatch control, wafers that do not require the activation of electrostatic neutralization and beam control devices during ion implantation are processed alternately with those that do. This avoids the problem of residual charge accumulation caused by the long-term shutdown of electrostatic neutralization and beam control devices, which leads to aging of the adsorption electrode material of the electrostatic chuck and extends the service life of the electrostatic chuck.

[0032] Specifically, step S1 is executed first, optimizing the wafer delivery plan through dispatch control equipment. Based on different types, the wafers are divided into a first wafer group and a second wafer group, and the ion implantation process for the first wafer group and the second wafer group is performed alternately. It should be understood that the terms "first" and "second" are mainly to distinguish different types of wafers. Here, it can be understood that the wafers in the first wafer group are wafer types that do not require the activation of electrostatic neutralization and beam current control devices during ion implantation, while the wafers in the second wafer group are wafer types that require the activation of electrostatic neutralization and beam current control devices during ion implantation.

[0033] Then, steps S2 and S3 are performed, in which the wafer is picked up by a robotic arm and placed on an electrostatic chuck of an ion implantation machine, and the wafer is electrostatically adsorbed by the electrostatic chuck for ion implantation.

[0034] Finally, step S4 is executed to monitor the wafers to be processed. When processing the wafers in the first wafer group, the electrostatic neutralization and beam current control device is adjusted from the on state to the off state; when processing the wafers in the second wafer group, the electrostatic neutralization and beam current control device is adjusted from the off state to the on state.

[0035] Preferably, before ion implantation of the wafer, the DC voltage applied to the adsorption electrode of the electrostatic chuck is adjusted to an optimal value, at which the electrostatic discharge capability of the electrostatic chuck is significantly improved. This optimal value can be obtained through multiple preliminary tests. According to the test results, the optimal value of the DC voltage applied to the adsorption electrode of the electrostatic chuck is 800V.

[0036] Preferably, before ion implantation of the wafer, the gripping speed of the robotic arm is adjusted to an optimal value, at which the electrostatic discharge capability of the electrostatic chuck is significantly improved. This optimal value can be obtained through multiple preliminary tests. According to the test results, the optimal gripping speed of the robotic arm is 30%.

[0037] Preferably, before ion implantation of the wafer, the ionization gas flow rate of the electrostatic neutralization and beam control device is adjusted to an optimal value, at which the electrostatic discharge capability of the electrostatic chuck is significantly improved. This optimal value can be obtained through multiple preliminary tests. According to the test results, the optimal value of the ionization gas flow rate of the electrostatic neutralization and beam control device is 12 Torr.

[0038] Preferably, before ion implantation of the wafer, the ionization voltage of the electrostatic neutralization and beam control device is adjusted to an optimal value, at which the electrostatic discharge capability of the electrostatic chuck is significantly improved. This optimal value can be obtained through multiple preliminary tests. According to the test results, the optimal value of the ionization voltage of the electrostatic neutralization and beam control device is 5V.

[0039] Based on the same inventive concept, embodiments of the present invention also propose a readable storage medium storing a computer program thereon, which, when executed, enables the above-mentioned method for improving the service life of electrostatic chucks.

[0040] A readable storage medium can be a tangible device capable of holding and storing instructions for use by an instruction execution device, such as, but not limited to, electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination thereof. The computer programs described herein can be downloaded from the readable storage medium to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. Networks can include copper transmission cables, fiber optic transmissions, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. Each computing / processing device's network adapter card or network interface receives and forwards a computer program from the network for storage on a readable storage medium within the respective computing / processing device. The computer program used to perform the operations of this invention can be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, status setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as "C" or similar languages. The computer program can execute entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuits, such as programmable logic circuits, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), are personalized by utilizing state information from a computer program. These electronic circuits can execute computer-readable program instructions, thereby realizing various aspects of the present invention.

[0041] Various aspects of the present invention are described herein with reference to flowchart illustrations and / or block diagrams of methods, systems, and computer program products according to embodiments of the invention. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by a computer program. These computer programs can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that, when executed by the processor of the computer or other programmable data processing apparatus, they create means for implementing the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. These computer programs can also be stored in a readable storage medium that causes a computer, programmable data processing apparatus, and / or other device to operate in a particular manner; thus, the readable storage medium storing the computer program comprises an article of manufacture including instructions for implementing aspects of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams.

[0042] A computer program may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the computer program executing on the computer, other programmable data processing apparatus, or other device to perform the functions / actions specified in one or more boxes of a flowchart and / or block diagram.

[0043] In summary, the embodiments of the present invention provide a method for improving the service life of electrostatic chucks and a readable storage medium. By optimizing the wafer routing scheme through dispatch control equipment, wafers that do not require the activation of electrostatic neutralization and beam control devices during ion implantation and wafers that do require the activation of electrostatic neutralization and beam control devices are alternately processed. This avoids the problem of residual charge accumulation caused by the long-term shutdown of electrostatic neutralization and beam control devices, which leads to aging of the adsorption electrode material of the electrostatic chuck, thereby improving the service life of the electrostatic chuck.

[0044] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure are within the protection scope of the present invention. Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the present invention and its equivalents, the present invention also intends to include these modifications and variations.

Claims

1. A method for improving the service life of an electrostatic chuck, characterized in that, include: The wafer delivery plan is optimized by dispatching control equipment. The wafers are divided into a first wafer group and a second wafer group according to their types. The ion implantation process of the first wafer group and the second wafer group is carried out alternately. The wafers in the first wafer group are wafers that do not require the electrostatic neutralization and beam current control devices to be turned on during the ion implantation process. The wafers in the second wafer group are wafers that require the electrostatic neutralization and beam current control devices to be turned on during the ion implantation process. The robotic arm picks up the wafer to be processed and places it on the electrostatic chuck of an ion implanter. The wafer to be processed is electrostatically adsorbed by the electrostatic chuck for ion implantation. When the wafer to be processed is a wafer in the first wafer group, the electrostatic neutralization and beam control device is adjusted from the on state to the off state; when the wafer to be processed is a wafer in the second wafer group, the electrostatic neutralization and beam control device is adjusted from the off state to the on state.

2. The method for improving the service life of an electrostatic chuck according to claim 1, characterized in that, Before ion implantation of the wafer, the DC voltage applied to the adsorption electrode of the electrostatic chuck is adjusted to an optimal value.

3. The method for improving the service life of an electrostatic chuck according to claim 2, characterized in that, The optimal value of the DC voltage applied to the adsorption electrode of the electrostatic chuck is 800V.

4. The method for improving the service life of an electrostatic chuck according to claim 1, characterized in that, Before ion implantation of the wafer, the gripping speed of the robotic arm is adjusted to the optimal value.

5. The method for improving the service life of an electrostatic chuck according to claim 1, characterized in that, Before ion implantation of the wafer, the ionization gas flow rate of the electrostatic neutralization and beam control device is adjusted to the optimal value.

6. The method for improving the service life of an electrostatic chuck according to claim 5, characterized in that, The optimal value for the ionized gas flow rate of the electrostatic neutralization and beam control device is 12 Torr.

7. The method for improving the service life of an electrostatic chuck according to claim 1, characterized in that, Before ion implantation of the wafer, the ionization voltage of the electrostatic neutralization and beam control device is adjusted to the optimal value.

8. The method for improving the service life of an electrostatic chuck according to claim 7, characterized in that, The optimal value for the ionization voltage of the electrostatic neutralization and beam control device is 5V.

9. A readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed, it can implement the method for improving the service life of electrostatic chucks according to any one of claims 1-8.

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