JP3558794B2 - Polishing method and polishing apparatus for semiconductor wafer - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing method and a polishing apparatus for polishing a semiconductor wafer with an optimal polishing time in order to maintain a film thickness to be polished with a predetermined value accurately in a polishing apparatus (polishing apparatus) for polishing a semiconductor wafer.
[0002]
[Prior art]
2. Description of the Related Art In a polishing apparatus (polishing apparatus) for polishing (polishing) a surface of a semiconductor wafer to a mirror surface, polishing of a wafer film thickness to a predetermined value is performed by controlling a polishing time. That is, the polishing amount is proportional to the polishing time when the polishing conditions such as the polishing speed and the surface pressure are constant. Therefore, the film thickness can be maintained at a predetermined value by controlling the polishing time.
[0003]
Conventionally, in order to obtain this polishing time, an operator first measures the film thickness of one semiconductor wafer before polishing (this is performed outside the apparatus in a normal polishing apparatus), and then the single semiconductor wafer is removed. Polishing is performed for a predetermined time by a polishing apparatus, and the film thickness of the semiconductor wafer is measured after the polishing (may be measured inside the polishing apparatus or outside the apparatus). The optimum polishing time is calculated from the target film pressure and the polishing time, and the subsequent polishing of the semiconductor wafer is performed with the optimum polishing time.
[0004]
[Problems to be solved by the invention]
However, the method of setting the polishing time as described above is a difficult task by hand, and at the same time, since the polishing time is set in one operation, the polishing conditions change while polishing continues, There is a problem that the polishing amount differs even with the same polishing time. For example, there is a problem that the surface of the polishing nonwoven fabric is worn out during long polishing, changes over time, and a difference in polishing amount occurs even in the same polishing time due to a component of the supplied polishing liquid or a change in temperature. There is.
[0005]
Further, as disclosed in, for example, Japanese Patent Publication No. 7-100297, the polishing amount and the polishing time in the polishing cycle of the already polished semiconductor wafer are sequentially accumulated, and the average polishing rate is calculated based on these accumulated values. In some cases, an optimum polishing time is calculated based on the average speed and a margin for polishing the semiconductor wafer in the next polishing cycle, and polishing in the next polishing cycle is performed based on the optimum polishing time. However, the method of calculating the optimum polishing time based on the average polishing speed of the accumulated polishing time cannot necessarily set the optimum polishing time.
[0006]
This is because in a polishing apparatus that continuously polishes semiconductor wafers one by one for each lot, the condition of the surface of the nonwoven fabric for polishing and the composition and temperature of the polishing liquid when the previous semiconductor wafer was finished are changed this time and next time. This has a great effect on semiconductor wear polishing, and the average polishing rate of the cumulative value of past polishing times does not necessarily have a great effect on the current or next polishing. Therefore, there is a problem that high-precision film thickness polishing cannot be performed.
[0007]
The present invention has been made in view of the above points, removes the above-mentioned problems, reflects the latest polishing nonwoven fabric surface conditions and polishing conditions such as polishing liquid components and temperatures in the polishing, high precision An object of the present invention is to provide a polishing method and a polishing apparatus for a semiconductor wafer which can be polished.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 includes a polishing step of loading a lot of semiconductor wafers, one lot of which is a lot, into a polishing apparatus, and polishing the semiconductor wafers one by one . A polishing method for a semiconductor wafer, comprising a film thickness measuring step of measuring a film thickness, and a polishing and film thickness measuring operation of the semiconductor wafer in these steps . The following polishing / thickness measurement operation, which is a polishing / thickness measurement operation for a semiconductor wafer, is performed. After the preceding polishing / thickness measurement operation, the polishing time and the target thickness value in the preceding polishing / thickness measurement operation are performed. , measured before polishing of the semiconductor wafer thickness value, and calculates a first optimum polishing time of the polishing process from the measured thickness value after the polishing, the first optimum polishing time in the semiconductor after a predetermined number-th calculated Polishing and film thickness of wafer And performing a polishing process of a constant work.
[0009]
Further, in the polishing and film thickness measuring work , the polishing and the film thickness measuring work may include cleaning the polished semiconductor wafer in the polishing step, drying the polished semiconductor wafer, and drying the semiconductor wafer. Is measured .
[0010]
According to the first and second aspects of the present invention, the subsequent polishing and film thickness measurement work, which is the next semiconductor wafer polishing and film thickness measurement operation, is performed in parallel with the preceding polishing work. Polishing efficiency is obtained. In addition, the optimum polishing time is calculated after the preceding polishing and film thickness measurement work, and the polishing step of the polishing and film thickness measurement work of the semiconductor wafer after the predetermined number of semiconductor wafers is performed with the calculated optimum polishing time. Even if the polishing conditions such as the condition of the woven fabric surface, the composition of the polishing liquid, and the temperature change, the changed latest polishing conditions can be reflected in the subsequent polishing of the semiconductor wafer. It can be polished to a film thickness.
[0011]
According to a third aspect of the present invention, in the method for polishing a semiconductor wafer according to the first or second aspect, after the preceding polishing / thickness measuring operation, the polishing / thickness measuring operation of the subsequent semiconductor wafer is performed. A second optimum polishing time is calculated from the polishing time, the target film thickness value, the measured film thickness value before the polishing step, and the measured film thickness value after polishing, and the second optimum polishing time after the predetermined number of sheets is calculated with the calculated second optimum polishing time. It is characterized in that a polishing step of the following semiconductor wafer polishing / film thickness measuring operation is performed .
[0012]
The invention of claim 4 is the method of polishing a semiconductor wafer over according to any one of claims 1 to 3, the polishing-thickness measurement operation of the first sheet of the semiconductor wafer in one lot The second semiconductor wafer is on standby until the process is completed.
[0013]
According to a fifth aspect of the present invention, in the method for polishing a semiconductor wafer according to the fourth aspect, after polishing and measuring the film thickness of the first semiconductor wafer in one lot , one semiconductor wafer in the one lot is subjected to the polishing. The first optimal polishing time is calculated from the polishing time, the target film thickness value, the measured film thickness value before polishing of the semiconductor wafer, and the measured film thickness value after polishing in the polishing / thickness measurement work of the second semiconductor wafer, The polishing step of the polishing and film thickness measurement of the second and third semiconductor wafers in one lot is performed at the calculated first optimum polishing time .
[0014]
According to a sixth aspect of the present invention, there is provided a polishing step of loading a lot of semiconductor wafers of one lot into a polishing apparatus for each lot and polishing the semiconductor wafers one by one, and measuring a film thickness of the semiconductor wafers. A semiconductor wafer polishing method for performing a semiconductor wafer polishing and film thickness measuring operation in these steps, wherein the polishing and the film thickness measuring operation are performed in parallel with the polishing and film thickness measurement of the next semiconductor wafer. A film thickness measurement operation is performed, and after the polishing / film thickness measurement operation of the first semiconductor wafer in one lot, the polishing time, the target film thickness value in the polishing / film thickness measurement operation, and the measurement film before polishing the semiconductor wafer are measured. The first optimum polishing time is calculated from the thickness value and the measured film thickness value after polishing, and the polishing process of the polishing / thickness measurement operation of the semiconductor wafer after a predetermined number of semiconductor wafers is performed at the calculated first optimum polishing time. Done, predetermined number After the polishing / thickness measuring operation of the semiconductor wafer, the polishing time, the target film thickness value, the measured film thickness value after polishing the semiconductor wafer, and the first semiconductor in the lot are measured. A second optimum polishing time is calculated from a measured film thickness value before polishing in a wafer polishing / film thickness measuring operation.
[0015]
According to a seventh aspect of the present invention, in the method for polishing a semiconductor wafer according to the sixth aspect, the polishing / thickness measuring operation includes cleaning the semiconductor wafer after polishing in a polishing step, and cleaning the semiconductor wafer after the cleaning. Drying the wafer and measuring the film thickness of the semiconductor wafer after the drying.
[0016]
The invention according to claim 8 is a polishing means for loading a lot of semiconductor wafers, one lot per lot, into a polishing apparatus, and polishing the semiconductor wafers one by one, and measuring the film thickness of the semiconductor wafers. A semiconductor wafer polishing apparatus comprising a film thickness measuring means for performing polishing and film thickness measurement of a semiconductor wafer by these means, wherein the polishing and film thickness measurement of the next semiconductor wafer are performed in parallel with the preceding polishing and film thickness measuring work. A subsequent polishing / thickness measurement operation, which is a polishing / thickness measurement operation, is performed. After completion of the preceding polishing / thickness measurement of the semiconductor wafer, the polishing time of the polishing means in the preceding polishing / thickness measurement operation, the target A first optimal polishing time is calculated from the film thickness value, the measured film thickness value before polishing of the semiconductor wafer, and the measured film thickness value after the polishing, and the first optimal polishing time after the predetermined number of sheets is calculated with the calculated first optimal polishing time. Polishing and film of semiconductor wafer Characterized in that a control means for performing measurement operations.
[0017]
According to a ninth aspect of the present invention, in the semiconductor wafer polishing apparatus according to the eighth aspect, after the semiconductor wafer is polished by the polishing means, the cleaning means for cleaning the semiconductor wafer, and the semiconductor wafer after the cleaning is removed. A drying means for drying is provided, and the film thickness of the semiconductor wafer after the drying is measured by the film thickness measuring means.
[0018]
According to a tenth aspect of the present invention, in the semiconductor wafer polishing apparatus according to the eighth or ninth aspect, the control means performs the polishing and film thickness measuring operation of the first semiconductor wafer in one lot. The first optimum polishing time is calculated from the polishing time in the polishing / thickness measurement operation, the target film thickness value, the measured film thickness value before polishing of the semiconductor wafer, and the measured film thickness value after polishing, and the calculated first polishing time is calculated. The polishing and film thickness measurement of the semiconductor wafer after the predetermined number of wafers are polished in the optimal polishing time of 1, and the polishing and film thickness measurement of the semiconductor wafer after the predetermined number of wafers are performed. From the polishing time, the target film thickness value, the measured film thickness value after polishing the semiconductor wafer, and the measured film thickness value before polishing in the polishing and film thickness measurement work of the first semiconductor wafer in the lot. The feature is to calculate the optimal polishing time of That.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of a polishing control device of a semiconductor wafer polishing apparatus according to the present invention. As shown in the figure, the present polishing control device includes a film thickness measuring unit 1, an input device 2, a polishing time calculation unit 3, a polishing time distribution unit 4, and a polishing unit control unit 5.
[0020]
The film thickness measuring section 1 has a pre-polishing measuring function 1a for measuring the film thickness of the semiconductor wafer before polishing and a post-polishing measuring function 1b for measuring the film thickness of the semiconductor wafer after polishing. enter a value M _I and the measured thickness value M _F after polishing the polishing time calculating unit 3. As will be described later in detail, the polishing time calculation unit 3 calculates the optimum polishing times T _{1 to TN} of the semiconductor wafers for the next and subsequent times each time polishing is completed, and outputs the calculated polishing times to the polishing time distribution unit 4. Note that a good measure thickness accuracy by measuring the film thickness at the film thickness measuring unit 1 measures the thickness of the plurality of points of the surface of the semiconductor wafer, to obtain a measurement thickness value M _I and M _F from the average value Value is obtained.
[0021]
The polishing section control section 5 includes a polishing time storage section 5a for storing an optimum polishing time for each semiconductor wafer to be polished, and the polishing time distribution unit 4 includes an optimum polishing time T ₁ calculated by the polishing time calculation unit 3. _TN are stored in the second, third,..., N−1, and N-th storage areas of the polishing time storage unit 5a. As will be described later in detail, the polishing section control section 5 controls the polishing section (polishing section) of the polishing apparatus with the optimum polishing times T _{1 to TN} stored in the polishing time storage section 5a to polish each semiconductor wafer.
[0022]
FIG. 2 is a diagram showing a schematic configuration of a polishing apparatus using the polishing control device. The polishing apparatus includes a load / unload unit 21, a transfer unit 22, a polishing (polishing) unit 23, a cleaning unit 24, and a polishing control unit shown in FIG. 1 for carrying in and transporting storage cases 25 and 25 'storing a large number of semiconductor wafers. Are arranged in a predetermined arrangement.
[0023]
The transfer device 22 is composed of a robot or the like, and takes out the semiconductor wafers one by one from the storage case 25 carried into the load / unload unit 21 and sends the semiconductor wafers to the film thickness measuring unit 1. The film thickness measuring unit 1 first measures the film thickness before polishing. Subsequently, the transfer device 22 transfers the semiconductor wafer, for which the film thickness measurement before polishing has been completed, to the polishing unit 23. In the polishing section 23, for example, the semiconductor wafer is brought into contact with the top ring at a predetermined pressure against the nonwoven fabric surface for polishing attached to the upper surface of the turntable, and the semiconductor wafer is moved for a predetermined time by the mutual movement due to the rotation of the top ring and the rotation of the turntable. Grind. The polishing time is carried out at the optimal polishing time stored in each storage area of the polishing time storing section 5a of the polishing unit control unit 5 as the T ₁ through T _N.
[0024]
The polished semiconductor wafer is sent to the cleaning unit 24 by the transfer unit 22, washed and dried by the cleaning unit 24, sent to the film thickness measurement unit 1 by the transfer unit 22, and polished by the film thickness measurement unit 1. After the film thickness is measured, the film is transferred to the load / unload unit 21 and stored in a storage case 25 ′ that is separately disposed in the load / unload unit 21 and stores the polished semiconductor wafer. You. One lot of semiconductor wafers stored in the storage case 25 as described above are taken out one by one by the transfer device 22, and the operations of polishing, washing / drying, and measuring the film thickness after polishing are repeated. When the above operation for all the semiconductor wafers in the storage case 25 has been polished, that is, when the polishing of one lot of semiconductor wafers has been completed, the polishing operation for the next lot is started.
[0025]
FIG. 3 and FIG. 4 are views showing the flow of the polishing processing operation of the above-mentioned polishing control device, and the polishing processing operation will be described with reference to FIG. First, in FIG. 3, a storage case 25 storing one lot (for example, 25) semiconductor wafers requiring polishing is set in the load / unload section 21 of the polishing apparatus. Then, enter the target thickness value M _T and the initial polishing from the input device 2 (polishing) time T _0. Is the target thickness value M _T is transferred to the polishing time calculation unit 3, an initial polishing time T ₀ is transferred to the polishing unit control unit 5 and the polishing time calculation unit 3, the polishing unit control unit 5 in the polishing time storage unit 5a It is stored in the first storage area.
[0026]
Initial polishing time T ₀ is the thickness is calculated the target thickness value empirically from the pre-polishing film thickness and the target film thickness value at the time required to polish to a M _T. As described above, the transfer device 22 takes out the _first semiconductor wafer W1 from the storage case 25 and transfers it to the film thickness measuring unit 1. At this time, the second sheet of semiconductor wafer W ₂ is in a standby state in the storage case 25. Thickness measuring unit 1 measures the film thickness before polishing of the semiconductor wafer W _1, and transfers the measured film thickness M _I in the polishing time calculating unit 3.
[0027]
Subsequently feeder 22 to transfer the semiconductor wafer W ₁ to the polishing section 23. Polishing only the initial polishing time T ₀ by the control of the polishing unit control unit 5 of the semiconductor wafer W ₁ In the polishing section 23. Conveying device 22 and the polishing is completed by transferring the semiconductor wafer W ₁ to the cleaning unit 24 by the conveying device 22 cleaned and dried semiconductor wafer W ₁ by the cleaning unit 24 is again transferred to the film thickness measurement section 1 , where it is measured the film thickness after polishing of the semiconductor wafer W ₁ is the measured thickness value M _F1 is transferred to the polishing time calculating unit 3. After the film thickness measurement completion, the semiconductor wafer W ₁ is transferred to the loading and unloading unit 21 by the transfer device 22, it is housed in the housing case 25 'which houses the semiconductor wafer after polishing.
[0028]
Following the polishing time calculation unit 3, the initial polishing time T _0, measured thickness value before polishing of the semiconductor wafer W ₁ M _I, optimum polishing from the measured thickness value M _F1 and the target thickness value M _T after polishing time (optimal polishing time to the target thickness value _{M T) T 1 {T 1} = f (M T, M I, M F1, T 0)} determined by calculating the. The optimum polishing time T ₁ is transferred to the polishing time distribution unit 4, and stores the second sheet and the storage area of the third sheet of the polishing time storage unit 5a of the polishing unit control unit 5.
[0029]
Once this optimum polishing time T ₁ is to confirm that the computed, the operator, as shown in FIG. 4 to cancel the standby, starts polishing operation of second and subsequent semiconductor wafer. Feeder 22 to transport the second sheet of the semiconductor wafer W ₂ in the polishing section 23 removed from the housing case 25. The control of the polishing unit 23 in the polishing unit control unit 5 is stored in the second sheet storage area of the polishing time storing unit 5a polishing the optimum polishing time T ₁ by the second sheet of the semiconductor wafer W _2.
[0030]
Feeder 22 transports the semiconductor wafer W ₂ ended polishing the cleaning unit 24, wherein the washed and dried semiconductor wafer W ₂ is transferred to the film thickness measurement unit 1 by the transfer device 22 again. Thickness measuring unit 1 measures the film thickness after polishing of the semiconductor wafer W _2, and transfers the measured film thickness M _F2 in polishing time calculating unit 3. The semiconductor wafer W ₂ that the film thickness after polishing is measured is transferred to the loading and unloading unit 21 by the transfer device 22, it is housed in the housing case 25 'which houses the semiconductor wafer after polishing.
[0031]
The polishing time calculation unit 3 calculates the target film thickness value M _T , the measured film thickness value M _I before polishing of the _second semiconductor wafer W ₂ , the measured film thickness value M _F2 after polishing, and the optimum polishing time T _1. optimum polishing time for polishing a 4 th semiconductor wafer _{W 4 T 4 {T 4 =} f (M T, M I, M F2, T 1)} determined by calculating the, the optimum polishing time _{T 4} the polishing time The data is transferred to the distribution unit 4 and stored in the fourth storage area of the polishing time storage unit 5a of the polishing unit control unit 5.
[0032]
The polishing work in parallel with the second sheet polishing operation of the semiconductor wafer W ₂ of the third sheet of semiconductor wafer W ₃ also start. The transfer device 22 takes out the third semiconductor wafer W3 from the storage case 25 and transfers it to the polishing unit 23. The polishing unit 23 controls the polishing unit control unit 5 to store the _third semiconductor wafer W3 in the polishing time storage unit 5a. in the optimum polishing time T ₁ is stored in the area for polishing the third sheet of the semiconductor wafer W _3.
[0033]
Semiconductor wafer W ₃ ended polishing is transferred to the cleaning unit 24 by the transport device 22, the semiconductor wafer W ₃ that has been cleaned and dried is transferred to a film thickness measuring unit 1, the film thickness after polishing by the film thickness measurement section 1 Is measured, and the film thickness measurement value _MF3 is transferred to the polishing time calculation unit 3. Semiconductor wafer W ₃ that the film thickness after polishing is measured is transferred to the loading and unloading unit 21 by the transfer device 22, it is housed in the housing case 25 'which houses the semiconductor wafer after polishing.
[0034]
The polishing time calculation unit 3 calculates the target film thickness M _T , the measured film thickness M _I before polishing of the _third semiconductor wafer W ₃ , the measured film thickness M _F3 after polishing, and the optimum polishing time T _1. 5th optimum polishing time _T 5 to polish the semiconductor wafer _{W 5 (T 5 = f (} M T, M I, M F3, T 3)) determined by calculating the, the optimum polishing time _{T 5} the polishing time The data is transferred to the distribution unit 4 and stored in the fifth storage area of the polishing time storage unit 5a of the polishing unit control unit 5.
[0035]
Grinding work 4 th semiconductor wafer W ₄ is transferred to the polishing section 23 takes out the semiconductor wafer W ₄ of the fourth sheet by the transfer device 22, the control of the polishing unit control unit 5 in the polishing section 23, the polishing time polishing the 4 th semiconductor wafer W ₄ at 4th stored in the storage area optimal polishing time T ₄ of the storage unit 5a.
[0036]
Semiconductor wafer W ₄ which has finished polishing is washed and dried in the cleaning section 24, is further transported to a film thickness measuring unit 1, the film thickness after polishing by a film thickness measuring unit 1 is measured and the measured thickness value M _F4 is transferred to the polishing time calculation unit 3, the semiconductor wafer W ₄ is accommodated in the storage case 25 'which houses the semiconductor wafer after polishing at the load-unload 21.
[0037]
The polishing time calculation unit 3 calculates the _sixth semiconductor wafer W ₆ from the target film thickness M _T , the measured film thickness M _I before polishing, the measured film thickness M _F4 after polishing, and the optimum polishing time T _4. Polishing time T ₆ {T ₆ = f (M _T , M _I , M _F4 , T ₄ )} is calculated, and this optimum polishing time T ₆ is transferred to the polishing time distribution unit 4 for polishing. It is stored in the sixth storage area of the polishing time storage unit 5a of the unit control unit 5.
[0038]
Similarly polishing work 5 th semiconductor wafer W ₅ after the completion of polishing is polished by optimum polishing time T _5, which are stored in the storage area of the 5th polishing time storage unit 5a of the polishing unit control section 5 below The optimum polishing time T ₇ for the _seventh wafer is calculated, and the polishing operation for the sixth semiconductor wafer W ₆ is performed in the polishing time storage unit 5 a of the polishing unit control unit 5. It is polished by T ₆ calculates the optimum polishing time T ₈ of 8 th after the completion of polishing.
[0039]
After such polishing the end of the K-th semiconductor wafer W _K, measured before polishing thickness value M _I, the film thickness measurement value M _FK after _polishing, optimum polishing time T _K from K + 2 th semiconductor wafer W _{K + 2} The polishing time T _{K + 2} (T _{K + 2} = f (M _T , M _I , M _FK , T _K )) for calculating the polishing time is calculated, and the ( _{K + 2} ) th storage of the polishing time storage unit 5 a of the polishing unit control unit 5 is stored. Store in area.
[0040]
In the above embodiment, the film thickness before polishing is measured only on the _first semiconductor wafer W1, and the measured film thickness value is used. However, the film thickness before polishing is measured for each wafer. Each time, the measured film thickness values M _I1 , M _{I2 to} M _IN may be obtained.
[0041]
In the above embodiment, the initial polishing time T _0, measured thickness value M _I before _polishing, measured thickness value M _F1 and the target thickness value M _T optimum polishing time obtained by calculation from the polished T ₁ {T ₁ = f (M _T , M _I , M _F1 , T ₀ )} is used for polishing the second and third semiconductor wafers. the While seeking calculates the optimum polishing time, it is not limited thereto, for example, the second sheet the optimum polishing time T _1, 3 sheet, used to polish 4 th semiconductor wafer, hereinafter be then determined by calculating the optimal polishing time of the semiconductor wafer to hit the third sheet to the polishing each finished good, also the optimum polishing time T ₁ is used for polishing of the second sheet of the semiconductor wafer, each polishing ends below The next half The optimal polishing time of the body wafer may be obtained by calculation.
[0042]
In short, after polishing the first sheet of the semiconductor wafer at an initial polishing time T _0, a predetermined next time from the measured thickness value M _F1 after polishing and measurement thickness value M _I before initial polishing time T ₀ and polishing The optimum polishing time up to the predetermined number of wafers is calculated, the semiconductor wafers up to the predetermined number of wafers are polished at the optimum polishing time, and thereafter, each time the polishing is sequentially completed, the optimum polishing time of the subsequent predetermined number of semiconductor wafers is calculated. The predetermined number of semiconductor wafers may be polished in the optimum polishing time.
[0043]
【The invention's effect】
As described above, according to the invention described in each claim, the following excellent effects can be obtained.
[0044]
Since the subsequent polishing / thickness measurement operation, which is the next semiconductor wafer polishing / thickness measurement operation, is performed in parallel with the preceding polishing operation, high polishing efficiency can be obtained.
[0045]
In addition, the optimum polishing time is calculated after the preceding polishing and film thickness measurement work, and the polishing step of the polishing and film thickness measurement work of the semiconductor wafer after the predetermined number of semiconductor wafers is performed with the calculated optimum polishing time. Even if the polishing conditions such as the condition of the surface of the fabric, the composition of the polishing liquid, and the temperature change, the changed latest polishing conditions can be reflected in the subsequent polishing of the semiconductor wafer, so that the film thickness of the semiconductor wafer can be adjusted with high precision. It can be polished to a film thickness.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a polishing control device of a semiconductor wafer polishing apparatus according to the present invention.
FIG. 2 is a diagram showing a schematic configuration of a polishing apparatus using the polishing control device of the present invention.
FIG. 3 is a diagram showing a flow of a polishing processing operation of the polishing control device of the present invention.
FIG. 4 is a diagram showing a flow of a polishing processing operation of the polishing control device of the present invention.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 film thickness measurement unit 2 input device 3 polishing time calculation unit 4 polishing time distribution unit 5 polishing unit control unit 21 load / unload unit 22 transfer device 23 polishing unit 24 cleaning unit 25 storage case 25 'storage case

Claims (10)

A polishing apparatus is loaded with a lot of semiconductor wafers, one lot per lot, and a polishing step of polishing the semiconductor wafers one by one , and a film thickness measuring step of measuring the film thickness of the semiconductor wafers. A semiconductor wafer polishing method for performing semiconductor wafer polishing and film thickness measurement work in ,
In parallel with the preceding polishing and film thickness measurement work, the subsequent polishing and film thickness measurement work of the next semiconductor wafer is performed.
After polishing, the film thickness measuring operation of the preceding polishing time in the polishing-thickness measuring operations this prior target thickness value, measured before the polishing of the semiconductor wafer thickness value, and measuring thickness value after the polishing Calculate the first optimal polishing time of the polishing process from
Polishing a semiconductor wafer and performing a first optimum polishing time in the polishing step of polishing, the film thickness measuring operation of the semiconductor wafer after the predetermined number-th that the calculated. The polishing / thickness measuring operation includes cleaning the semiconductor wafer after polishing in the polishing step, drying the semiconductor wafer after cleaning, and measuring the film thickness of the semiconductor wafer after drying. The method for polishing a semiconductor wafer according to claim 1, wherein: After the preceding polishing and film thickness measurement operation, the polishing time, the target film thickness value, the measured film thickness value before the polishing step, and the measured film thickness value after polishing in the subsequent polishing and film thickness measurement operation of the semiconductor wafer. Calculate the second optimal polishing time from
3. The method of polishing a semiconductor wafer according to claim 1, wherein a polishing step of polishing and measuring a film thickness of the next semiconductor wafer after the predetermined number is performed at the calculated second optimum polishing time. . 4. The semiconductor according to claim 1, wherein the second semiconductor wafer waits until the polishing / thickness measurement of the first semiconductor wafer in the one lot is completed. 5. Wafer polishing method. After the work of polishing and measuring the thickness of the first semiconductor wafer in the one lot, the polishing time, the target film thickness value, and the target thickness of the semiconductor wafer in the work of measuring the thickness of the first semiconductor wafer in the one lot are measured. The first optimum polishing time is calculated from the measured film thickness value before polishing and the measured film thickness value after polishing,
5. The semiconductor according to claim 4, wherein the polishing and the film thickness measurement of the second and third semiconductor wafers in the one lot are performed in the calculated first optimal polishing time. 6. Wafer polishing method. A polishing apparatus is loaded with a lot of semiconductor wafers, one lot per lot, and a polishing step of polishing the semiconductor wafers one by one, and a film thickness measuring step of measuring the film thickness of the semiconductor wafers. A method of polishing a semiconductor wafer, which performs a polishing and film thickness measurement operation of the semiconductor wafer in,
Perform the polishing and film thickness measurement work of the next semiconductor wafer in parallel with the polishing and film thickness measurement work,
After the polishing / thickness measuring operation of the first semiconductor wafer in the one lot, the polishing time, the target film thickness value, the measured film thickness value before polishing the semiconductor wafer, and the polishing in the polishing / thickness measuring operation The first optimal polishing time is calculated from the measured film thickness value afterward,
Performing the polishing step of the polishing and film thickness measurement work of the predetermined number of semiconductor wafers after the first number at the calculated first optimal polishing time,
After the polishing / thickness measuring operation of the semiconductor wafer after the predetermined number, the polishing time, the target film thickness value in the polishing / thickness measuring operation, the measured film thickness value after polishing the semiconductor wafer, and the A second optimum polishing time is calculated from a measured film thickness value before polishing in the polishing and film thickness measurement operation of the first semiconductor wafer. The polishing / thickness measuring operation includes washing the polished semiconductor wafer in a polishing step, drying the washed semiconductor wafer, and measuring the thickness of the dried semiconductor wafer. 7. The method for polishing a semiconductor wafer according to claim 6, wherein the polishing is performed. A polishing apparatus is equipped with a lot of semiconductor wafers, one lot per lot, and a polishing means for polishing the semiconductor wafers one by one, and a film thickness measuring means for measuring the film thickness of the semiconductor wafer. A semiconductor wafer polishing apparatus for performing a semiconductor wafer polishing and film thickness measuring operation by means,
In parallel with the preceding polishing and film thickness measurement work, a subsequent polishing and film thickness measurement operation that is the following polishing and film thickness measurement operation of the next semiconductor wafer is performed, and the polishing and film thickness of the preceding semiconductor wafer are performed. After the measurement is completed, the first optimum value is obtained from the polishing time of the polishing means, the target film thickness value, the measured film thickness value before polishing the semiconductor wafer, and the measured film thickness value after the polishing in the preceding polishing / film thickness measurement work. A polishing apparatus for a semiconductor wafer, comprising: a control means for calculating a polishing time and performing a polishing / film thickness measuring operation of a predetermined number of semiconductor wafers after the first optimum polishing time. After the semiconductor wafer is polished by the polishing means, cleaning means for cleaning the semiconductor wafer, drying means for drying the semiconductor wafer after the cleaning is provided, and the film thickness of the dried semiconductor wafer is measured by the film thickness measuring means. The apparatus for polishing a semiconductor wafer according to claim 8, wherein the measurement is performed. After the polishing / thickness measuring operation of the first semiconductor wafer in the one lot, the control means controls a polishing time, a target film thickness value in the polishing / thickness measuring operation, and a measurement film of the semiconductor wafer before the polishing. A first optimal polishing time is calculated from the thickness value and the measured film thickness value after polishing, and the polishing for the polishing / thickness measurement operation of the semiconductor wafer after a predetermined number of semiconductor wafers is performed at the calculated first optimal polishing time. After the polishing and film thickness measurement of the semiconductor wafer after the predetermined number of times, the polishing time, the target film thickness, the measured film thickness after polishing of the semiconductor wafer, and the 1 lot 10. The polishing of a semiconductor wafer according to claim 8, wherein the second optimum polishing time is calculated from the measured film thickness value before polishing in the polishing and film thickness measuring operation of the first semiconductor wafer in the above. apparatus.

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