CN116423378A - Metal film thickness on-line measurement compensation method, film thickness sensor and equipment - Google Patents
Metal film thickness on-line measurement compensation method, film thickness sensor and equipment Download PDFInfo
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B37/00—Lapping machines or devices; Accessories
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B1/00—Processes of grinding or polishing; Use of auxiliary equipment in connection with such processes
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B37/00—Lapping machines or devices; Accessories
- B24B37/11—Lapping tools
- B24B37/20—Lapping pads for working plane surfaces
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B37/00—Lapping machines or devices; Accessories
- B24B37/27—Work carriers
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B37/00—Lapping machines or devices; Accessories
- B24B37/34—Accessories
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B47/00—Drives or gearings; Equipment therefor
- B24B47/10—Drives or gearings; Equipment therefor for rotating or reciprocating working-spindles carrying grinding wheels or workpieces
- B24B47/12—Drives or gearings; Equipment therefor for rotating or reciprocating working-spindles carrying grinding wheels or workpieces by mechanical gearing or electric power
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B49/00—Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B51/00—Arrangements for automatic control of a series of individual steps in grinding a workpiece
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Abstract
The invention discloses a metal film thickness online measurement compensation method, a film thickness sensor and equipment, wherein the method comprises the following steps: in the polishing process, the nth output S of the film thickness sensor for measuring the metal film thickness is obtained n The method comprises the steps of carrying out a first treatment on the surface of the By sensing the film thickness at this timeTemperature t of the device sn And self temperature drift function, calculating sensor temperature drift compensation quantity delta S sn The method comprises the steps of carrying out a first treatment on the surface of the By using the wafer temperature t at this time wn Film thickness d measured n-1 th time n‑1 And calculating a wafer temperature drift compensation amount delta S according to the wafer temperature compensation function wn The method comprises the steps of carrying out a first treatment on the surface of the Calculating the compensated output S n ′ ，S n ′ ＝S n ‑ΔS sn ‑ΔS wn The method comprises the steps of carrying out a first treatment on the surface of the According to the sensor output function and the compensated output quantity S n ′ Obtaining the film thickness d measured for the nth time n 。
Description
Technical Field
The invention relates to the technical field of chemical mechanical polishing, in particular to a metal film thickness online measurement compensation method, a film thickness sensor and equipment.
Background
Chemical mechanical polishing (Chemical Mechanical Polishing, CMP) technology is the first planarization process in IC fabrication. In chemical mechanical polishing, excessive or insufficient material removal can result in degradation or even failure of the device electrical properties for the semiconductor device manufacturing process. In order to improve the controllability of the chemical mechanical polishing process, improve the stability of the product, reduce the defect rate of the product, and enable each wafer to achieve uniform production, the endpoint detection technology (Endpoint Detection, EPD) of chemical mechanical polishing is developed.
In the CMP process, a large amount of heat is generated due to mechanical friction and chemical reaction, and the heat is transmitted to the wafer on one hand, so that the conductivity of the metal film changes when the temperature of the wafer rises; on the other hand, heat is conducted to the eddy current sensor through the polishing disc, so that the working temperature of the eddy current sensor is changed. The conductivity of the wafer metal film and the working temperature of the eddy current sensor change, so that the eddy current sensor measures the thickness of the wafer metal film to generate errors, and finally the grabbing of the polishing end point is affected.
Disclosure of Invention
The embodiment of the invention provides a metal film thickness online measurement compensation method, a film thickness sensor and equipment, which aim to at least solve one of the technical problems in the prior art.
A first aspect of the embodiment of the invention provides a metal film thickness online measurement compensation method, which comprises the following steps:
in the polishing process, the nth output S of the film thickness sensor for measuring the metal film thickness is obtained n ；
By using the film thickness at this timeSensor temperature t sn And self temperature drift function, calculating sensor temperature drift compensation quantity delta S sn ；
By using the wafer temperature t at this time wn Film thickness d measured n-1 th time n-1 And calculating a wafer temperature drift compensation amount delta S according to the wafer temperature compensation function wn ；
Calculating the compensated output S' n ，S′ n ＝S n -ΔS sn -ΔS wn ；
Based on the sensor output function and the compensated output S' n Obtaining the film thickness d measured for the nth time n 。
In one embodiment, the sensor output function is calibrated from a mapping relationship between the output of the film thickness sensor and the actual film thickness at normal temperature, and the sensor output function is expressed as d=f 1 (S), wherein d is the film thickness of the wafer, and S is the output of the film thickness sensor.
In one embodiment, the self temperature drift function is calibrated by the mapping relation between the output of the film thickness sensor at different temperatures and the temperature, and is expressed as delta S s ＝f 2 (t s ) Wherein DeltaS s T is the temperature drift compensation quantity of the sensor s Is the temperature of the film thickness sensor.
In one embodiment, the wafer temperature compensation function is calibrated by the output of film thickness sensors corresponding to different film thicknesses of the wafer at different temperatures, and is expressed as ΔS w ＝f 3 (t w D), wherein DeltaS w Is the compensation quantity of the wafer temperature drift, t w The wafer temperature, d, is the film thickness of the wafer.
In one embodiment, the specific calculation process includes:
ΔS sn ＝f 2 (t sn )
ΔS wn ＝f 3 (t wn ，d n-1 )
S′ n ＝S n -ΔS sn -ΔS wn
d n ＝f 1 (S′ n )
wherein f 2 F is the self temperature drift function 3 F is the wafer temperature compensation function 1 A function is output for the sensor.
In one embodiment, the output of the film thickness sensor is a resonant frequency.
The second aspect of the embodiment of the invention provides a film thickness sensor, which adopts the metal film thickness online measurement compensation method to measure the film thickness; the film thickness sensor comprises an eddy current module, a detection circuit and a temperature measurement module.
A third aspect of an embodiment of the present invention provides a chemical mechanical polishing apparatus, comprising:
a polishing disk for covering a polishing pad for polishing a wafer;
the bearing head is used for holding the wafer and pressing the wafer on the polishing pad, and a temperature detection unit is arranged on the bearing head;
the film thickness sensor as described above for measuring the film thickness of a wafer during polishing;
and the control device is used for realizing the metal film thickness online measurement compensation method.
A fourth aspect of the embodiments of the present invention provides a control apparatus including a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor implementing the steps of the metal film thickness online measurement compensation method as described above when executing the computer program.
A fifth aspect of the embodiments of the present invention provides a computer-readable storage medium storing a computer program which, when executed by a processor, implements the steps of the metal film thickness online measurement compensation method as described above.
The beneficial effects of the embodiment of the invention include: the influence of temperature change on film thickness measurement can be compensated, and the accuracy and precision of film thickness measurement are obviously improved.
Drawings
The advantages of the present invention will become more apparent and more readily appreciated from the detailed description given in conjunction with the following drawings, which are meant to be illustrative only and not limiting of the scope of the invention, wherein:
FIG. 1 illustrates a chemical mechanical polishing apparatus provided in accordance with one embodiment of the present invention;
FIG. 2 shows a film thickness sensor provided by an embodiment of the present invention;
FIG. 3 shows a graph of film thickness versus film thickness sensor output;
FIG. 4 shows a graph of output of a film thickness sensor as a function of temperature;
FIG. 5 shows a binary variation of the output of a film thickness sensor with film thickness and temperature;
FIG. 6 shows an on-line measurement compensation method for metal film thickness according to an embodiment of the present invention;
fig. 7 shows a comparison of the film thickness sensor before and after temperature compensation.
Detailed Description
The following describes the technical scheme of the present invention in detail with reference to specific embodiments and drawings thereof. The examples described herein are specific embodiments of the present invention for illustrating the concept of the present invention; the description is intended to be illustrative and exemplary in nature and should not be construed as limiting the scope of the invention in its aspects. It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. In addition to the embodiments described herein, those skilled in the art can adopt other obvious solutions based on the disclosure of the claims of the present application and the specification thereof, including those adopting any obvious substitutions and modifications to the embodiments described herein. It should be understood that the following description of the embodiments of the present invention, unless specifically stated otherwise, is established in the natural state of the relevant devices, apparatuses, components, etc. in which no external control signal or driving force is given, in order to facilitate understanding.
Furthermore, it is noted that terms such as front, back, upper, lower, left, right, top, bottom, front, back, horizontal, vertical, and the like used herein are merely used for ease of description to aid in understanding the relative position or orientation and are not intended to limit the orientation of any apparatus or structure.
In order to describe the technical solution according to the invention, reference will be made to the accompanying drawings and examples.
In this application, chemical mechanical polishing (Chemical Mechanical Polishing) is also referred to as chemical mechanical planarization (Chemical Mechanical Planarization), and wafers are also referred to as wafers, silicon chips, substrates or substrates (substrates), etc., and their meaning and actual function are equivalent.
As shown in fig. 1, the main components of the chemical mechanical polishing apparatus provided by the embodiment of the present invention are a carrier head 10 for holding a wafer w and rotating the wafer w, a polishing disk 20 covered with a polishing pad 21, a dresser 30 for dressing the polishing pad 21, and a liquid supply portion 40 for supplying a polishing liquid.
In the chemical mechanical polishing process, the carrier head 10 sucks the wafer w by negative pressure and presses a surface of the wafer w containing the metal film against the polishing pad 21, and the carrier head 10 makes a rotational motion and reciprocates in a radial direction of the polishing platen 20 so that the surface of the wafer w in contact with the polishing pad 21 is gradually polished while the polishing platen 20 rotates, and the liquid supply part 40 sprays the polishing liquid to the surface of the polishing pad 21. The wafer w is rubbed against the polishing pad 21 by the relative motion of the carrier head 10 and the polishing platen 20 under the chemical action of the polishing liquid to perform polishing. The conditioner 30 is used to condition and activate the surface topography of the polishing pad 21 during polishing. The use of the dresser 30 can remove impurity particles remaining on the surface of the polishing pad 21, such as abrasive particles in the polishing liquid, and waste material detached from the surface of the wafer w, and can planarize the surface deformation of the polishing pad 21 due to the polishing.
During chemical mechanical polishing, the wafer w is pressed against the polishing pad 21 by the carrier head 20 and reciprocated radially of the polishing platen 10 with the carrier head 20, and simultaneously, the carrier head 20 and the polishing platen 10 are rotated synchronously, so that the surface of the wafer w in contact with the polishing pad 21 is gradually polished.
As shown in fig. 2, the chemical mechanical polishing apparatus further includes a film thickness sensor 50 for measuring the film thickness of the wafer w on line and a control device. The film thickness sensor 50 is installed in the polishing disk 20 below the polishing pad 21. The film thickness sensor 50 rotates following the polishing disk 20 to perform film thickness on-line measurement while polishing. The film thickness sensor 50 is disposed next to the polishing pad 21, and the wafer w is placed on the polishing pad 21, so that the distance from the film thickness sensor 50 to the wafer w is the thickness of the polishing pad 21.
In the CMP polishing process, the film thickness variation and the film thickness value of the wafer w need to be monitored in real time so as to adopt a corresponding polishing process, and over polishing or incomplete polishing is avoided. In the polishing process, the metal film thickness on the surface of the wafer w is measured on line, so that the removal rate of the metal film is accurately controlled by adjusting the pressure of the bearing head 10, and better global planarization is realized. The film thickness sensor 50 may employ an eddy current detection, which is based on the principle that the film thickness sensor 50 induces eddy currents in a metal film layer on the surface of the wafer w when the film thickness sensor 50 sweeps across the wafer w, so that the film thickness sensor 50 measures the eddy current changes to measure the film thickness of the metal film layer when the metal film layer is removed by polishing.
The temperature drift occurs due to the large heat generated during the CMP polishing process, such that the temperature of the wafer w rises, the operating temperature of the film thickness sensor 50 and the calibrated temperature are not uniform. Therefore, the output variation of the film thickness sensor 50 during polishing is composed of three parts: firstly, the output changes caused by the film thickness changes of the metal film to be measured, and the change curve is shown in figure 3; second, the output of the film thickness sensor 50 changes due to temperature changes, the change curve is shown in fig. 4; and thirdly, the output changes caused by the change of the conductivity of the measured metal film due to the temperature change, and the change curve is shown in fig. 5. Finally, the output of the film thickness sensor 50 is coupled together by these three portions.
In order to accurately measure the temperature change during polishing, as shown in fig. 1 and 2, in one embodiment of the present invention, a temperature detecting unit 11 is provided on the carrier head 10, for acquiring the temperature of the wafer w or the surface temperature of the polishing pad near the wafer w, so that wafer temperature compensation can be achieved. As shown in fig. 2, the film thickness sensor 50 includes an eddy current module 51, a detection circuit, and a temperature measurement module 52, wherein the eddy current module 51 is used for detecting the metal film thickness, and the temperature measurement module 52 is used for detecting the temperature change of the film thickness sensor 50 so as to realize the self temperature drift compensation of the film thickness sensor 50.
Based on the above chemical mechanical polishing apparatus and the composition structure of the film thickness sensor 50, as shown in fig. 6, an embodiment of the present invention further provides an online measurement compensation method for metal film thickness, including:
step S1, during polishing, the nth output S of the film thickness sensor 50 for measuring the metal film thickness is obtained n . The output of the film thickness sensor 50 is the resonance frequency. The sampling frequency and output frequency of the film thickness sensor 50 are generally fixed, and the output quantity is continuously output at certain intervals, the output quantity S n The data directly output from the film thickness sensor 50 at the nth time is n, which is a natural number.
Step S2, using the film thickness sensor temperature t at that time sn And self temperature drift function, calculating sensor temperature drift compensation quantity delta S sn . Wherein, the temperature measuring module 52 is used for collecting the temperature t of the film thickness sensor sn The self temperature drift function is calibrated by the mapping relation between the output of the film thickness sensor 50 at different temperatures and the temperature, and can be expressed as delta S s ＝f 2 (t s )，ΔS s T is the temperature drift compensation quantity of the sensor s Is the temperature of the film thickness sensor.
Step S3, using the wafer temperature t at this time wn Film thickness d measured n-1 th time n-1 And calculating a wafer temperature drift compensation amount delta S according to the wafer temperature compensation function wn . Wherein, the temperature detection unit 11 is used for collecting the wafer temperature t wn The wafer temperature compensation function is obtained by calibrating the output of the film thickness sensor 50 corresponding to the different film thicknesses of the wafer at different temperatures, and can be expressed as ΔS w ＝f 3 (t w ，d)，ΔS w Is the wafer temperature driftCompensation quantity, t w The wafer temperature, d, is the film thickness of the wafer.
Step S4, calculating the compensated output S' n ，S′ n ＝S n -ΔS sn -ΔS wn 。
Step S5, according to the sensor output function and the compensated output quantity S' n Obtaining the film thickness d measured for the nth time n . Wherein the sensor output function is calibrated by the mapping relation between the output of the film thickness sensor and the actual film thickness at normal temperature, and can be expressed as d=f 1 (S), d is the film thickness of the wafer, and S is the output of the film thickness sensor.
It will be appreciated that the sensor output function f described above 1 Self temperature drift function f 2 And a wafer temperature compensation function f 3 May be represented by a relationship curve, a data calibration table, or a fitting function.
In one embodiment, before the metal film thickness online measurement compensation method shown in fig. 6 is executed, a calibration process is further needed, which specifically includes:
calibrating the mapping relation between the output of the film thickness sensor and the actual film thickness at normal temperature to obtain the output function d=f of the film thickness sensor 1 (S). For example, a Cu film wafer with different film thickness is placed on the film thickness sensor 50 at a fixed lift-off height and an ambient temperature of 24 ℃ to obtain a sensor output function f at a calibrated temperature 1 (S), as shown in FIG. 3, may represent a sensor output function f 1 And (S) a relation between film thickness and output.
Calibrating the mapping relation between the output of the film thickness sensor at different temperatures and the temperature to obtain the self temperature drift function delta S of the film thickness sensor s ＝f 2 (t s ). Specifically, the film thickness sensor 50 is placed in an accurate temperature control device, and the relationship between the output of the film thickness sensor and the temperature is calibrated, so as to obtain the self temperature drift function f 2 (t s ) Fig. 4 shows the output of the film thickness sensor as a function of temperature under no-load conditions.
Calibrating wafers at different temperaturesThe output of the film thickness sensor corresponding to different film thicknesses to obtain a wafer temperature compensation function delta S w ＝f 3 (t w D) is provided. Specifically, the film thickness sensor 50 and the Cu film wafers with different film thicknesses are placed in an accurate temperature control device, and the lift-off height between the film thickness sensor 50 and the Cu film wafers is kept unchanged, so that the wafer temperature compensation function f with different film thicknesses and different temperatures is obtained 3 (t w D) is provided. Because the metal conductivity changes with the temperature, the output of the film thickness sensor also changes with the temperature under the same thickness of the metal film, and as shown in fig. 5, the output of the film thickness sensor changes with the binary change curve graph of the metal film thickness and the temperature.
In a specific application, in the nth output S of the film thickness sensor n The film thickness d measured last, i.e., the n-1 st time, is used for compensation n-1 The specific calculation process comprises the following steps:
(1) Calculating self drift of the film thickness sensor: ΔS sn ＝f 2 (t sn )；
(2) Calculating drift due to wafer temperature variation: ΔS wn ＝f 3 (t wn ，d n-1 )；
(3) Eliminating drift to obtain compensated output quantity: s'. n ＝S n -ΔS sn -ΔS wn ；
(4) Calculating a true film thickness using the compensated output quantity: d, d n ＝f 1 (S′ n )。
In the polishing process, the chemical mechanical polishing equipment does not have severe chemical reaction at the beginning and the temperature is not increased, the temperature at the moment is consistent with the calibration temperature, and the output quantity S of the film thickness sensor 1 Is accurate and can directly obtain the film thickness d without temperature compensation 1 . The temperature change of the wafer surface is acquired in real time by using the temperature detection unit 11 due to the heat generated by the chemical reaction in the polishing process, and the temperature change of the film thickness sensor is acquired in real time by the temperature measurement module 52, so that the temperature compensation calculation is performed according to the calculation process.
For ease of understanding, the following illustrates specific implementations:
and the accurate film thickness after each compensation can be obtained by analogy according to the calculation rule in the table.
As shown in FIG. 7, the applicant verifies the technical effect of the metal film thickness online measurement compensation method provided by the embodiment of the invention through experiments. Measurement of the cu film thickness of the sample using a four-probe instrument was
As shown in FIG. 7, in the range of temperature change from 15 to 35 ℃, if the measurement accuracy of the film thickness sensor without temperature compensation is +.>
The measurement accuracy of the film thickness sensor after the temperature compensation is increased to +.>
The measurement accuracy is improved by 10 times. In addition, the metal film thickness online measurement compensation method is also applicable to the surface planarization and end point grabbing and stopping of the CMP wafer in the W and AL processes.
Therefore, the metal film thickness online measurement compensation method provided by the embodiment of the invention can compensate the influence of temperature change on film thickness measurement, and the accuracy and precision of film thickness measurement are obviously improved.
The embodiment of the invention also provides a control device, which comprises: a processor, a memory, and a computer program stored in the memory and executable on the processor. The processor, when executing the computer program, carries out the method steps as shown in fig. 6. The control device refers to a terminal with data processing capability, including but not limited to a computer, a workstation, a server, and even Smart phones, palm computers, tablet computers, personal Digital Assistants (PDAs), smart televisions (Smart TVs), and the like with excellent performances. The control device typically has an operating system installed thereon, including but not limited to: windows operating system, LINUX operating system, android operating system, symbian operating system, windows mobile operating system, iOS operating system, etc. Specific examples of the control device are listed above in detail, and those skilled in the art will recognize that the control device is not limited to the above listed examples.
The embodiment of the invention also provides a computer readable storage medium, wherein the computer readable storage medium stores a computer program, and the computer program realizes the steps of the method shown in fig. 6 when being executed by a processor. The computer program may be stored in a computer readable storage medium, which computer program, when being executed by a processor, may carry out the steps of the various method embodiments described above. Wherein the computer program comprises computer program code which may be in source code form, object code form, executable file or some intermediate form etc. The computer readable medium may include: any entity or device capable of carrying the computer program code, a recording medium, a U disk, a removable hard disk, a magnetic disk, an optical disk, a computer Memory, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), an electrical carrier signal, a telecommunications signal, a software distribution medium, and so forth.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
The above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention, and are intended to be included in the scope of the present invention.
Claims (10)
1. The online metal film thickness measuring and compensating method is characterized by comprising the following steps of:
in the polishing process, the nth output S of the film thickness sensor for measuring the metal film thickness is obtained n ；
By using the film thickness sensor temperature t at this time sn And self temperature drift function, calculating sensor temperature drift compensation quantity delta S sn ；
By using the wafer temperature t at this time wn Film thickness d measured n-1 th time n-1 And calculating a wafer temperature drift compensation amount delta S according to the wafer temperature compensation function wn ；
Calculating the compensated output S' n ，S′ n ＝S n -ΔS sn -ΔS wn ；
Based on the sensor output function and the compensated output S' n Obtaining the film thickness d measured for the nth time n 。
2. The method for online measurement and compensation of metal film thickness according to claim 1, wherein the sensor output function is calibrated by a mapping relationship between an output of a film thickness sensor and an actual film thickness at normal temperature, and the sensor output function is expressed as d=f 1 (S), wherein d is the film thickness of the wafer, and S is the output of the film thickness sensor.
3. The online measurement and compensation method of metal film thickness according to claim 1, wherein the self temperature drift function is calibrated by mapping relation between output of film thickness sensor at different temperatures and temperature, and is expressed as Δs s ＝f 2 (t s ) Wherein DeltaS s T is the temperature drift compensation quantity of the sensor s Is the temperature of the film thickness sensor.
4. The method for online measurement and compensation of metal film thickness according to claim 1, wherein the wafer temperature compensation function is obtained by calibrating output of film thickness sensors corresponding to different film thicknesses of wafers at different temperatures, and is expressed as Δs w ＝f 3 (t w D), wherein DeltaS w Is the compensation quantity of the wafer temperature drift, t w The wafer temperature, d, is the film thickness of the wafer.
5. The method for compensating for on-line measurement of metal film thickness as set forth in claim 1, wherein the specific calculation process comprises:
ΔS sn ＝f 2 (t sn )
ΔS wn ＝f 3 (t wn ，d n-1 )
S′ n ＝S n -ΔS sn -ΔS wn
d n ＝f 1 (S′ n )
wherein f 2 F is the self temperature drift function 3 F is the wafer temperature compensation function 1 A function is output for the sensor.
6. The method for compensating for on-line measurement of a metal film thickness according to claim 1, wherein the output of the film thickness sensor is a resonance frequency.
7. A film thickness sensor, characterized in that film thickness measurement is performed by using the metal film thickness on-line measurement compensation method according to any one of claims 1 to 6; the film thickness sensor comprises an eddy current module, a detection circuit and a temperature measurement module.
8. A chemical mechanical polishing apparatus, comprising:
a polishing disk for covering a polishing pad for polishing a wafer;
the bearing head is used for holding the wafer and pressing the wafer on the polishing pad, and a temperature detection unit is arranged on the bearing head;
the film thickness sensor according to claim 7, for measuring a film thickness of a wafer during polishing;
a control device for realizing the metal film thickness online measurement compensation method according to any one of claims 1 to 6.
9. A control device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, the processor implementing the steps of the metal film thickness on-line measurement compensation method according to any one of claims 1 to 6 when the computer program is executed.
10. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program which, when executed by a processor, implements the steps of the metal film thickness online measurement compensation method according to any one of claims 1 to 6.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117207056A (en) * | 2023-11-07 | 2023-12-12 | 苏州博宏源机械制造有限公司 | High-precision wafer laser thickness measuring device and method |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117207056A (en) * | 2023-11-07 | 2023-12-12 | 苏州博宏源机械制造有限公司 | High-precision wafer laser thickness measuring device and method |
| CN117207056B (en) * | 2023-11-07 | 2024-01-23 | 苏州博宏源机械制造有限公司 | High-precision wafer laser thickness measuring device and method |
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