METHOD OF CHEMICAL MECHANICAL POLISH OPERATION AND CHEMICAL MECHANICAL POLISHING SYSTEM
The present disclosure provides a method of chemical mechanical polish operation and a chemical mechanical polish operation system. The method includes obtaining a first input parameter and a second input parameter, wherein the first input parameter is associated with an additive of a slurry, and the second input parameter is associated with a characteristic of a process apparatus, determining an output parameter associated with the process apparatus based on the first input parameter and the second input parameter, securing a workpiece by a head over a platen in the process apparatus, supplying the slurry with the additive over the platen with the additive configured with the first parameter, and polishing a surface of the workpiece by operating the process apparatus configured with the output parameter.
The manufacturing of the semiconductor devices with an increased device density is becoming increasingly complicated. Among the various semiconductor processing steps, planarization or polishing schemes, e.g., chemical mechanical polish (CMP) has been widely used for thinning or polishing a processed surface of the semiconductor device. The polishing is performed with the help of slurry to facilitate the polishing efficiency and performance. The performance of the polishing operation is therefore closely related to the quality of the slurry.
Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.
The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.
Further, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature’s relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.
Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the disclosure are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the deviation normally found in the respective testing measurements. Also, as used herein, the terms “about,” “substantial” or “substantially” generally mean within 10%, 5%, 1% or 0.5% of a given value or range. Alternatively, the terms “about,” “substantial” or “substantially” mean within an acceptable standard error of the mean when considered by one of ordinary skill in the art. Other than in the operating/working examples, or unless otherwise expressly specified, all of the numerical ranges, amounts, values and percentages such as those for quantities of materials, durations of times, temperatures, operating conditions, ratios of amounts, and the likes thereof disclosed herein should be understood as modified in all instances by the terms “about,” “substantial” or “substantially.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the present disclosure and attached claims are approximations that can vary as desired. At the very least, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Ranges can be expressed herein as being from one endpoint to another endpoint or between two endpoints. All ranges disclosed herein are inclusive of the endpoints, unless specified otherwise.
The terms “couple,” “coupled” and “coupling” used throughout the present disclosure describe the direct or indirect connections between two or more devices or elements. In some cases, a coupling between at least two devices or elements refers to mere electrical or conductive connections between them and intervening features may be present between the coupled devices and elements. In some other cases, a coupling between at least two devices or elements may involve physical contact and/or electrical connections.
The term “parameter” used throughout the present disclosure is not limited to a single numerical value. The term “parameter” may be referred to a group of values, a series of values, value or values derived from a plurality of factors, or different levels of data (such as groups and subgroups of data).
Chemical mechanical polish (CMP) is a skill for smoothing a non-uniform surface during a fabrication operation. In order to sustain the quality of production, it is important to monitor and address the factors that could influence the outcome and reliability of CMP operations. In some cases, the variation of a slurry regarding the chemical composition, such as a chemical property or a physical property, may affect the reliability of CMP operations. The details are discussed in
Referring to
Referring to
Therefore, it is important to address the aforesaid issue of the decay of additive in the slurry chemical compositions, such as regarding the concentration of the additive (e.g. H2O2) in the slurry, in order to facilitate the CMP operation and maintain the reliability of manufacturing operations. However, in fabrication lab practice, the supply of the additive to the slurry is mostly performed at the chemical supplying apparatus 1′ (the delivery end) and may be conducted manually with low frequency (such as daily or twice a day), which faces the difficulty of addressing the decay issue quickly and effectively. In some cases, it is found that even by supplying the additive at the delivery end, the composition of the slurry proximal to the process apparatus 2′ (the process end) and/or in the conduit 3′ may not promptly change accordingly due to the long distance, wherein the CMP operation utilizing the decayed slurry may be undesirably performed across multiple wafers, multiple batches of wafers, or lots of wafers. The failure of recognizing the problem caused by the decay issue and other related factors (such as input parameters A-1 to A-4 as discussed with reference to
Accordingly, the present disclosure provides a method of chemical mechanical polish operation and chemical mechanical polish operation system to address the aforesaid issue, which will be subsequently discussed in
Referring to
Referring to
Referring to
The process apparatus 2 includes a platen 11 and a pad 12 disposed over the platen 11. The process apparatus 2 has a slurry arm 14 configured to dispense the slurry that is utilized in the CMP operation of a workpiece 99 (such as a wafer or a substrate), which can be secured by a head 13 during such CMP operation. The platen 11 and the head 13 rotate during the CMP operation, wherein in some embodiments, the platen 11 rotates in a first direction FD, and the head 13 rotates in a second direction SD. In some embodiments, the first direction FD is identical to the second direction SD, such as both are clockwise or counterclockwise. In some alternative embodiments, the first direction FD is reverse to the second direction SD. In some embodiments, the process apparatus 2 further includes a manifold 6 configured to distribute and control the inflow of the slurry in the conduit 3, and a flow controller 7 configured to control the flow rate of the slurry in the conduit 3. The process apparatus 2 may further include a dresser 19 for conditioning the pad 12 by removing residues. The dresser 19 applies a downforce on the pad 12 to facilitate the conditioning of a top surface of the pad 12 due to greater friction.
In some of the embodiments, the slurry may include an additive for facilitating the CMP operation, such as H2O2 (hydrogen peroxide) can be utilized as oxidizer. As previously discussed in
It should be noted that although the weight concentration of additives are utilized as an example in the present disclosure, the volume percent, molecular percentage or other expressions representative of the concentration of specific chemicals in the slurry can be applied as well.
The conduit 3 includes several portions, such as a first portion 3a in (or proximal to) the chemical supplying apparatus 1, a second portion 3b between the chemical supplying apparatus 1 and the manifold 6 of the process apparatus 2, a third portion 3c between the manifold 6 and the flow controller 7. and a fourth portion 3d between the flow controller 7 and an exit end 14E of the slurry arm 14.
Referring to
Alternatively stated, referring to the method 3000 shown in the schematic block diagram in
The sensors 5a, 5b, 5c, 5d can be electrically connected to a controller 4, thereby allowing the sensors 5a, 5b, 5c, 5d to transmit a signal associated with the parameters A-1 and A-2 of the slurry to the controller 4. Alternatively stated, the controller 4 is configured to receive a signal associated with values of the parameters A-1 and A-2 from the sensors 5a, 5b, 5c, 5d. Herein the controller 4 in the present disclosure can be implemented by software such that the foregoing methods disclosed therein can be automatically performed. For a general purpose computer, the software routines can be stored on a storage device, such as a permanent memory. Alternately, the software routines can be machine executable instructions stored using any machine readable storage medium, such as a diskette, CD-ROM, magnetic tape, digital video or versatile disk (DVD), laser disk, ROM, flash memory, etc. The series of instructions could be received from a remote storage device, such as a server on a network. The present disclosure can also be implemented in hardware systems, microcontroller unit (MCU) modules, discrete hardware or firmware. Furthermore, the controller 4 may include a timer and/or a memory to store a preset schedule.
Referring to
Still referring to
In some embodiments, the head 13 includes a retaining ring 13R configured to secure the workpiece 99 during CMP operation, a top portion 13T over the position of workpiece 99 when the workpiece 99 is secured by the head 13, and a membrane 13MB between the top portion 13T and the pad 12 over the platen 11. The membrane 13MB may be made of soft material and can be configured to serve as a buffer layer to alleviate undesired damage on a first surface 99S of the workpiece 99 facing the top portion 13T of the head 13 (wherein the first surface 99S is a surface opposite to a second surface 99Q to be polished by the pad 12).
One or more first thermal meter 21 can be disposed at the top portion 13T of the head 13 of the CMP apparatus 2a, and the first thermal meter 21 may be facing toward the pad 12 and the membrane 13MB. In some embodiments, the first thermal meter 21 is configured to obtain a temperature of the membrane 13MB proximal to the top portion 13T of the head 13. In some embodiments, a detection surface 21D of the first thermal meter 21 overlaps with the membrane 13MB in vertical direction Z In some of the embodiments, the first thermal meter 21 is a non-contact temperature measurement device, such as infrared thermal meter or other suitable radiation-based sensing device. In some embodiments, a distance t21 between the first surface 99S of the workpiece 99 and the detection surface 21D of the first thermal meter 21 is less than about 5 cm. When the distance t21 is greater than 5 cm, the accuracy of temperature measurement may decrease.
In some embodiments, one or more second thermal meter 22 can be disposed at the retaining ring 13R, which is at a peripheral area of the head 13. In some of the embodiments, the second thermal meter 22 is at least partially embedded in the retaining ring 13R, and has a detecting surface 22D facing the pad 12. In some embodiments, the second thermal meter 22 is configured to obtain a temperature of the slurry on the pad 12 (or the temperature of the pad 12 in some alternative embodiments). In some of the embodiments, the second thermal meter 22 is a non-contact temperature measurement device, such as infrared thermal meter or other suitable radiation-sensing device. In some embodiments, a distance t22 between the top surface 12T of the pad 12 and the detection surface 22D of the second thermal meter 22 is less than about 5 cm. When the distance t22 is greater than 5 cm, the accuracy of temperature measurement may decrease.
One or more third thermal meter 23 can be disposed in the platen 11 and under the pad 12. In some embodiments, the third thermal meter 23 has a detection surface 23D facing the pad 12. In some embodiments, the platen 11 includes one or more channels 11C disposed therein, which can be configured to accommodate the third thermal meter(s) 23. In some embodiments, the channels 11C is an empty receptacle. In some alternative embodiments, the channels 11C can also be a receptacle filled with fillers. The third thermal meter 23 can be configured to obtain a temperature of the slurry on the pad 12 (or in some alternative embodiments, the temperature of the pad 12). In some of the embodiments, the third thermal meter 23 is a non-contact temperature measurement device, such as infrared thermal meter or other suitable radiation-sensing device. In some embodiments, at least a portion of the pad 12 (e.g. the portions directly above the third thermal meter(s) 23) is substantially transparent or semitransparent for the wavelength of the radiation utilized by the third thermal meter 23. For example, the transparency thereof may be in a range from about 10% to about 100%, thereby allowing at least a portion of the radiation to pass through the pad 12. In some of the embodiments, the transparency of the portion in the pad 12 may be in a range from 30% to about 70% for some of the materials that may be suitable to be fabricated as the pad 12. With such configuration, the radiation emitted from the third thermal meter 23 may be reflected by the head 13. The temperature obtained by the third thermal meter 23 is determined by one or more of a temperature of the head 13, a temperature of the pad 12, a temperature of the slurry, and the heat released during the CMP operation. In some alternative embodiments, the pad 12 is made of an opaque material, wherein the temperature obtained by the third thermal meter 23 is mainly determined by a temperature of the pad 12, however, herein a temperature of the pad 12 may be influenced by a temperature of the head 13, a temperature of the slurry, and the heat released during the CMP operation.
In some embodiments, the first thermal meter 21, the second thermal meter 22, and the third thermal meter 23 measure temperatures during CMP operation (starting from the initialization of the CMP operation, which is after the slurry is supplied, and end at the termination of the CMP operation), and for each type of the thermal meters, the sampling of temperature data may be conducted periodically or triggered by event, and the temperature can be obtained by averaging multiple temperature data at different sampling time points through the thermal meter, or can be substituted/supported by other specific analysis methods (such as filtering out the outlier data, sampling peak values, obtaining trending lines, et cetera).
Referring to
In some embodiments, the third thermal meter 23 can be arranged in various fashions to comply with specific requirements. Several embodiments will be subsequently described as examples in
Referring back to
In operation 3031 (as shown in
Referring to
In some embodiments, the technique of reinforcement learning is utilized in order to optimize the computational model 602, such as using an evaluator parameters (Parameters C) which are associated with a performance of a CMP operation performed on a workpiece 99 and can be obtained by measuring feature(s) of the workpiece 99 (shown in
The training method discussed in the present disclosure is not limited to reinforcement learning. For example, the computational model may utilize any other suitable types of neural network architectures and learning techniques, such as Convolutional Neural Network (CNN), Recurrent Neural Network (RNN), Long/Short term Memory (LSTM), Gated Recurrent Unit (GRU), Neural Tuning Machine (NTM), Support Vector Machine (SVM), Kohonen Network (KN), Deep Residue Network (DRN). Generative Adversarial Network (GAN), Liquid State Machine (LSM), Extreme Learning Machine (ELM). Echo State Network (ESN). Deconvolutional Network (DN), Deep Convolutional Network (DCN), Deep Convolutional Inverse Graphics Network (DCIGN), Auto Encoder (AE), Variation Auto Encoder (VAE), Denoising Auto Encoder (DAE), Sparse Auto Encoder (SAE) Perception (P), Feed Forward (FF), Radial Basis Network (RBF), Deep Feed Forward (DFF). Markov Chain (MC), Hopfield Network (HN), Boltzmann Machine (BM), Restricted Boltzmann Machine (RBM), Deep Belief Network (DBN), or the like. In some alternative embodiments, the training method discussed in the present disclosure includes a combination of two or more learning techniques.
In operation 3032 (as shown in
In some embodiments, the platen 11 and/or the head 13 (shown in
In some of the embodiments, operation 3041 and operation 3042 as shown in
Referring back to
In some alternative embodiments, the aforesaid evaluator parameters (parameters C) can instead be obtained during the CMP operation in real time, wherein the CMP apparatus 2a includes the sensors 5a, 5b, 5c, 5d. Such configuration may further improve the accuracy of controlling the CMP operation on the workpiece 99 since the computational model of parameter determination can be adjusted in real time accordingly.
Alternatively stated, a feedback operation can be used to enhance the training result of the computational model, as shown in
The aforesaid feedback operation may allow the controller 4 to adjust the computational model for parameter determination of the controller 4, for example, adjusting the weight of each parameter B in the computational model, wherein each of the parameters B in the current and/or the following CMP operations (i.e. on another workpiece) may be adjusted accordingly. Therefore, the determination of relation between the variations of input parameters and the output parameters can be adjusted in time when performing CMP operation on the next workpiece 99 (also can be referred to the second workpiece) or the next batch/next lot.
Referring to
In some embodiments, the auxiliary compensation apparatus 9 may include one or more auxiliary compensation device at the process end proximal to the process apparatus 2, for example, a first auxiliary compensation device 9a disposed at the second portion 3b of the conduit 3, a second auxiliary compensation device 9b disposed at the third portion 3c of the conduit 3, and/or a third auxiliary compensation device 9c disposed at the fourth portion 3d of the conduit 3, wherein the second portion 3b is between the chemical supplying apparatus 1 and the manifold 6 of the process apparatus 2, the third portion 3c is between the manifold 6 and the flow controller 7, and the fourth portion 3d is between the flow controller 7 and an exit end 14E of the slurry arm 14. In some embodiments, the CMP operation system 200 includes one of the first auxiliary compensation device 9a. the second auxiliary compensation device 9b, and the third auxiliary compensation device 9c; while in some alternative embodiments, the CMP operation system 200 includes more than one of first auxiliary compensation device 9a, the second auxiliary compensation device 9b, and the third auxiliary compensation device 9c. In some embodiments, the auxiliary compensation apparatus 9 is electrically connected to the controller 4.
The auxiliary compensation apparatus 9 can be utilized to supply an amount of an additional additive to the slurry in the conduit 3 before the slurry is dispensed from the exit end 14E of the slurry arm 14. In some embodiments, the amount of the additive (such as H2O2) supplied by the auxiliary compensation apparatus 9 is based on the parameter A-1,which is associated with the slurry at the first position proximal to the chemical supplying apparatus 1 (such as a concentration of the additive (e.g. as H2O2) or another chemical in the slurry) and/or a parameter A-2, which is associated with the slurry at the second position proximal to the process apparatus 2 (such as a concentration of the additive (e.g. as H2O2) or another chemical in the slurry). The detailed description can be found by referring back to the discussion for
In some embodiments, the auxiliary compensation apparatus 9 is configured to perform operation 3015 as shown in
It should be further noted that, in some embodiments, the auxiliary compensation apparatus 9 provides a storage that alleviates or reduce the decay of the additive (such as H2O2), for example, by providing a controlled environment with a constant pressure and/or a constant temperature and isolated from the influence of the ambient environment, et cetera.
The location-specific configuration of the auxiliary compensation apparatus 9 proximal to the dispense arm 14 helps addressing the issue of decay of the additive in the slurry due to the long transmission distance between the delivery end and the process end, as well as the idle time, as previously discussed in
The present disclosure provides a method of chemical mechanical polish (CMP) operation and a CMP operation system to address the issue of fluctuating performance of CMP operations. The issue may stem from the unstable additive (such as H2O2) in the slurry, wherein a concentration of the additive in the slurry may decrease after being transmitted through a relatively long distance and/or over a period of idle time. The issue may also stem from other variations, such as factors of ambient environment and the conditions of CMP apparatus 2a. As discussed in
Furthermore, a feedback mechanism discussed in
As discussed in
Some embodiments of the present disclosure provide a method for polishing a workpiece. The method includes obtaining a first input parameter and a second input parameter, wherein the first input parameter is associated with an additive of a slurry, and the second input parameter is associated with a characteristic of a process apparatus, determining an output parameter associated with the process apparatus based on the first input parameter and the second input parameter, securing a workpiece by a head over a platen in the process apparatus, supplying the slurry with the additive over the platen with the additive configured with the first parameter, and polishing a surface of the workpiece by operating the process apparatus configured with the output parameter.
Some embodiments of the present disclosure provide a method for polishing a workpiece. The method includes obtaining a first parameter associated with at least one of an additive of a slurry and a first characteristic of a process apparatus, and a second parameter associated with a second characteristic of the process apparatus, determining a value of the second parameter in response to determining that the first parameter fails to comply with a predetermined specification, securing a workpiece by a head over a platen in the process apparatus, supplying the slurry with the additive over the platen, and planarizing a surface of the workpiece by operating the process apparatus with the second parameter configured with the determined value.
Some embodiments of the present disclosure provide a chemical mechanical operation system. The CMP operation system includes a platen in a process apparatus, a process apparatus including a platen, a conduit, connected to a chemical supplying apparatus configured to supply a slurry, a slurry arm connected to the conduit, wherein the slurry arm is configured to supply the slurry over the platen, a sensor attached to the conduit, wherein the sensor in configured to obtain a concentration of an additive in the slurry, a controller electrically connected to the platen, configured to receive a signal associated with the concentration of the additive in the slurry.
The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other operations and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.
Claims
1. A method for polishing a workpiece, comprising:
- obtaining a first input parameter and a second input parameter, wherein the first input parameter is associated with an additive of a slurry, and the second input parameter is associated with a characteristic of a process apparatus;
- determining an output parameter associated with the process apparatus based on the first input parameter and the second input parameter;
- securing a workpiece by a head over a platen in the process apparatus;
- supplying the slurry with the additive over the platen with the additive configured with the first parameter; and
- polishing a surface of the workpiece by operating the process apparatus configured with the output parameter.
2. The method of claim 1, wherein the first input parameter comprises a concentration of the additive in the slurry proximal to a chemical supplying apparatus configured to supply the slurry, and a concentration of the additive in the slurry proximal to the process apparatus.
3. The method of claim 1, wherein obtaining the first input parameter comprises: obtaining the first input parameter by a sensor proximal to a chemical supplying apparatus configured to supply the slurry, or a sensor disposed in the process apparatus.
4. The method of claim 1, wherein obtaining the second input parameter comprises: obtaining the second input parameter by a first thermal meter disposed at a top portion of the head.
5. The method of claim 1, wherein obtaining the second input parameter comprises: obtaining the second input parameter by a second thermal meter disposed at a retaining ring of the head.
6. The method of claim 1, wherein obtaining the second input parameter comprises: obtaining the second input parameter by a third thermal meter disposed in the platen.
7. The method of claim 1, wherein the output parameter comprises at least one of the following: a rotational speed of the platen, a head pressure applied by the head, a downforce applied by a dresser against a pad over the platen, a temperature of working fluid flowing in the platen, or a flow rate of working fluid flowing in the platen.
8. A method for polishing a workpiece, comprising:
- obtaining a first parameter associated with at least one of an additive of a slurry and a first characteristic of a process apparatus, and a second parameter associated with a second characteristic of the process apparatus;
- determining a value of the second parameter in response to determining that the first parameter fails to comply with a predetermined specification;
- securing a workpiece by a head over a platen in the process apparatus;
- supplying the slurry with the additive over the platen; and
- planarizing a surface of the workpiece by operating the process apparatus with the second parameter configured with the determined value.
9. The method of claim 8, wherein the first parameter comprises a concentration of the additive in the slurry.
10. The method of claim 8, wherein obtaining the first parameter comprises: obtaining the first parameter by a sensor attached to a conduit that supplies the slurry.
11. The method of claim 8, wherein the second parameter comprises at least one of the following: a rotational speed of the platen, a head pressure applied by the head, or a downforce applied by a dresser against a pad over the platen.
12. The method of claim 8, wherein the second parameter is determined by a computational model.
13. The method of claim 12, further comprising obtaining a value of a third parameter after planarizing the workpiece, wherein the third parameter is associated with a performance of the planarizing of the surface of the workpiece.
14. The method of claim 13, wherein the computational model is trained by the first parameter, the second parameter, and the third parameter.
15. A chemical mechanical polish (CMP) operation system, comprising:
- a process apparatus comprising a platen;
- a conduit, connected to a chemical supplying apparatus configured to supply a slurry;
- a slurry arm connected to the conduit, wherein the slurry arm is configured to supply the slurry over the platen;
- a sensor attached to the conduit, wherein the sensor in configured to obtain a concentration of an additive in the slurry;
- a controller electrically connected to the platen, configured to receive a signal associated with the concentration of the additive in the slurry.
16. The CMP operation system of claim 15, further comprising a pad over the platen, wherein at least a portion of the pad is transparent or semitransparent.
17. The CMP operation system of claim 15, further comprising a head over the platen and a first thermal meter disposed at a top portion of the head.
18. The CMP operation system of claim 15, further comprising:
- a head over the platen;
- a second thermal meter on a retaining ring of the head, wherein the first thermal meter and the second thermal meter are configured to rotate around a first axis of the head.
19. The CMP operation system of claim 15, further comprising:
- a third thermal meter disposed in the platen, wherein the third thermal meter is configured to rotate around a second axis of the platen.
20. The CMP operation system of claim 15, further comprising an auxiliary compensation apparatus connected to the conduit at a position proximal to the process apparatus, wherein the auxiliary compensation apparatus is configured to supply the additive to the slurry.
Type: Application
Filed: Feb 17, 2022
Publication Date: Aug 17, 2023
Inventors: CHUNHUNG CHEN (HSINCHU), YU-CHU HSU (HSINCHU), REN-DOU LEE (HSINCHU CITY)
Application Number: 17/674,569