JP3118743B2 - Plasma processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus.

[0002]

2. Description of the Related Art Plasma processing apparatuses have been widely applied to semiconductor manufacturing processes or LCD substrate manufacturing processes. Such a plasma treatment apparatus includes, for example, an upper electrode and a lower electrode arranged in parallel in a processing chamber,
Plasma is generated from the process gas by the discharge between the upper electrode and the lower electrode while the semiconductor wafer as the object to be processed is placed on the lower electrode, and the semiconductor wafer is etched with its active species, or the semiconductor wafer is generated with a reaction product gas. Is formed. In order to monitor the progress of the plasma processing, instrumental analysis techniques such as mass spectrometry and spectroscopic analysis are used. Among these instrumental analyses, a spectroscopic analysis method by detecting a change in a specific wavelength is widely used as an end point detection method for plasma processing.

For example, when the end point of etching is detected, a specific active species consumed by etching, such as reactive ions, is extracted from active species such as radicals and ions such as an etching gas and its decomposition product gas and reaction product gas. The end point of the etching is detected by measuring the change in the intensity of the emission spectrum of the selected reactive ion. Depends active species etching gas to be measured, for example, emission spectra from CO ^* is the reaction product gas in the case of etching the silicon oxide film using the CF-based etching gas, such as CF ₄ (219 nm or 483.5 nm).
When a silicon nitride film is etched using a CF-based etching gas such as CF ₄ , an emission spectrum (eg, 674 nm) from N ^* which is a reaction product gas is measured. When such detection is performed, the emission spectrum transmitted through the monitoring window provided in the processing chamber is detected by an end point detection device provided with a spectroscopic analyzer provided outside the processing chamber. When the etching is repeated, generated gas (including a reaction product and the like, the same applies hereinafter) is generated by an etching reaction or the like during the etching in the processing chamber, and this gas adheres to the inner surface of the processing chamber, and this deposits to generate particles. Cause. Further, when the produced gas adheres to the monitoring window, the transparent glass such as quartz is clouded, so that the intensity of the emission spectrum transmitted through the transparent glass gradually decreases, and it becomes impossible to detect an accurate end point gradually. For this reason, cleaning has conventionally been performed regularly to ensure the transparency of the transparent glass, to obtain the accuracy of end point detection, and to prevent the generation of particles. Such a treatment is performed not only for etching but also for other plasma treatments.

[0004]

However, in the case of the conventional plasma processing apparatus, since the monitoring window is provided in accordance with the peripheral wall of the processing chamber, the gas generated by the plasma processing is in contact with the inner peripheral wall of the processing chamber. Similarly, it adheres to the transparent glass of the monitoring window.Before the cleaning of the processing chamber, the transparent glass becomes cloudy, the detection accuracy of the emission spectrum decreases, or the detection becomes difficult, and the accurate end point cannot be detected. The cleaning of the transparent glass must be performed separately from the cleaning of the processing chamber, which causes a problem that the cleaning interval is shortened and the operation efficiency of the apparatus is reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and it is intended to suppress the adhesion of generated gas to the transparent glass of a monitoring window for plasma monitoring to increase the number of times of plasma processing of an object to be processed. It is an object of the present invention to provide a plasma processing apparatus for improving the operation efficiency of a plasma processing apparatus.

[0006]

According to a first aspect of the present invention, there is provided a plasma processing apparatus which generates plasma in a processing chamber, performs plasma processing on an object to be processed by the plasma, and is provided in the processing chamber. In a plasma processing apparatus configured to detect the emission intensity of the plasma transmitted through the monitoring window and monitor the plasma processing based on the detected value, a cylindrical body protrudes from an opening formed in a peripheral wall of the processing chamber. this outer end of the cylindrical body provided with a monitoring window, a and position to the first trap portion the cylinder body between the peripheral wall and the monitoring window of the processing chamber into the cylinder body together with the connecting by A stenosis member partitioned into the second trap portion is provided, and the stenosis member has a tubular portion continuously provided as a stenosis portion from a central hole thereof to a peripheral wall of the processing chamber. Things.

A plasma processing apparatus according to a second aspect of the present invention is the plasma processing apparatus according to the first aspect, wherein a temperature adjusting mechanism having at least a cooling means is provided in the cylindrical body. It is assumed that.

[0008]

According to the first aspect of the present invention, when a plasma is generated in the processing chamber and the object to be processed is subjected to plasma processing, for example, etching, by the plasma, a specific emission spectrum in the plasma in the processing chamber is generated. Penetrates the monitoring window, detects the end point of the etching by detecting the plasma intensity at this time, terminates the etching when the end point is detected, and repeats the etching. Although such reaction product gas is deposited directly, monitor window from the peripheral wall of the processing chamber does not adhere directly to the monitor window for which is remote outward from the opening of the peripheral wall of the processing chamber into the cylindrical body When product gas enters after trapping the generated gases in the first trap portion formed by constriction member in the cylindrical body, the product gas in the first trap portion through the cylindrical portion of the constriction member When the amount is limited and enters the second trap portion, the generated gas is trapped in the second trap portion immediately before the monitoring window, and the amount of generated gas adhering to the monitoring window is suppressed to extend the period in which the end point can be detected. it can.

[0009] According to the invention described in claim 2 of the present invention, in the invention described in claim 1, for providing a temperature adjusting mechanism having at least cooling means to said cylindrical body, the cylindrical body by the cooling means by cooling to promote adhesion of the product gas before and after the constriction member of the cylinder body, by increasing the trap amount of the product gas can be suppressed adhesion of the product gas for the monitoring window.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the plasma etching apparatus shown in FIGS. The processing apparatus of the present embodiment is configured as a reactive ion etching (RIE) apparatus. This RIE device, as shown in FIG.
The processing chamber 1 is formed in a cylindrical shape from a conductive material such as aluminum, for example. The processing chamber 1 is configured in an airtight structure, and the inside of the processing chamber 1 is evacuated through an exhaust pipe 2 by a vacuum pump (not shown) to, for example, from 0.1 mTorr to several T.
It is configured so that a vacuum atmosphere of about orr can be formed. A lower electrode 4 on which a semiconductor wafer 3 is placed is disposed on the bottom surface of the processing chamber 1 by using a conductive material such as aluminum, and the lower electrode 4 is configured to support the semiconductor wafer 3. . The lower electrode 4
Is connected to a high-frequency power supply 6 via a blocking capacitor 5. The high-frequency power supply 6 applies a high-frequency power of, for example, 13.56 MHz to the lower electrode 4 via the blocking capacitor 5. On the other hand, an upper electrode 7 opposed to the lower electrode 4 is disposed above the lower electrode 4 so as to be grounded to maintain a ground potential.
1 to supply an etching gas into the processing chamber 1 as shown by an arrow in FIG. Therefore,
After the inside of the processing chamber 1 is evacuated from, for example, 0.1 mTorr to several Torr through the exhaust pipe 2, an etching gas is supplied from the upper electrode 7 and the etching gas pressure in the processing chamber 1 is maintained at a predetermined degree of vacuum. When high-frequency power is applied to the lower electrode 4 from the high-frequency power source 6, a vacuum discharge occurs between the lower electrode 4 and the upper electrode 7 using the etching gas as a medium, and a plasma composed of active species such as reactive ions and radicals and electrons from the etching gas. 8 is generated.

A monitoring window 10 made of transparent glass such as quartz glass for monitoring plasma is attached to a part of the peripheral wall 9 of the processing chamber 1, and the emission spectrum of the plasma 8 is transmitted through the monitoring window 10. The progress of the etching is monitored by the end point detection device 11 via the transmitted light. This end point detection device 11
A lens 12 facing the monitoring window 10;
A photodetector 13 for detecting the light condensed by the photodetector and performing photoelectric conversion, and detecting an end point of the etching based on an electric signal according to an emission spectrum transmitted from the photodetector 13 and controlling the control signal at the time of detecting the end point. End point arithmetic unit 14 that transmits
And the controller 1 that receives a control signal from the end-point calculator 14 to control the high-frequency power source 6 to end the etching.
5 is provided. Also, the photodetector 13
Although not shown, for example, an interference filter or a spectroscope, and a photomultiplier photodiode are provided. After the light of a specific wavelength is separated by the interference filter or the spectroscope, the separated light of the specific wavelength is photoelectrically converted to reduce the emission intensity I. It is configured to transmit as an electric signal.

Next, the monitoring window 10 of the processing chamber 1 constituting a main part of the present embodiment will be described. This monitoring window 10
2 is disposed outside the peripheral wall 9 of the processing chamber 1 at a distance from the peripheral wall 9 as shown in FIGS. That is, an opening 16 is formed in a part of the peripheral wall 9 of the processing chamber 1, and a cylindrical member, for example, a cylindrical body 17 formed of the same material as that of the processing chamber 1 is provided on the opening 16 via a sealing member 18. It is connected to keep the inside airtight. The cylindrical body 17 horizontally projects outward from the peripheral wall 9 by a predetermined distance outward,
A transparent glass 21 is connected to an opening 20 of the protruding end face 19 via a sealing member 22 so as to keep the inside airtight.
The monitoring window 10 is constituted by the above. In addition, cylindrical body 1
7 is provided on the inner peripheral surface thereof with a narrowing member 23 integrally formed therewith. The generated gas diffuses from the opening 16 of the processing chamber 1 to the monitoring window 10 via the cylindrical body 17 by the narrowing member 23. Of the generated gas is trapped between the processing chamber 1 and the constricting member 23, and a part of the generated gas is further trapped between the constricting member 23 and the monitoring window 10 so that the generated gas is transparent. It is configured so as not to adhere to the glass 21 as much as possible. That is, the first and second trap portions 24 and 25 are formed on the left and right sides of the constriction member 23 in the cylindrical body 17, and the first and second trap portions 24 and 25 allow the gas flowing into each of them to stay. To capture gas.

The stenosis member 23 is an annular part 26 fixed so as to divide the inside of the cylindrical body 17 into two parts at the middle and right and left, and extends as a stenosis part from the inner peripheral end of the annular part 26 to the processing chamber 1 side. And a cylindrical portion 27 formed. The cylindrical portion 27 may be formed in a tapered shape. The ratio (D / d) of the inner diameter D of the cylindrical portion 27 to the diameter d of the opening 16 of the processing chamber 1 is preferably formed in the range of 0.2 to 0.7. Further, it is preferable that the length L of the cylindrical portion 27 is 5 to 30 mm. On the other hand, the distance l between the extended end of the cylindrical portion 27 and the peripheral wall 9 is preferably set to 5 to 30 mm. By setting the stenosis member 23 to such dimensions and positional relationship, the adhesion of the generated gas to the monitoring window 10 can be minimized.

A cooling means such as a cooling jacket or a heating means such as a tape heater is attached to the cylindrical body 17 as necessary as a temperature adjusting mechanism 28. By this temperature adjusting mechanism 28, gas is supplied to the monitoring window 10. It is configured to suppress adhesion. That is, when a cooling means such as a cooling jacket is attached, the first and second cooling means are provided.
The cooling of the trap portions 24 and 25 promotes the gas adhesion at these portions, suppresses the amount of gas reaching the monitoring window 10, and suppresses the gas adhesion to the monitoring window 10. Also,
When a heating means such as a tape heater is attached, the adhesion of gas at the first and second trap portions 24 and 25 and the monitoring window 10 can be suppressed by heating the entire cylindrical body 17. .

The end point calculator 14 is configured, for example, as shown in FIG. The end-point calculator 14 extracts detection elements such as the intensity I and the first derivative (slope) of the input signal from the photodetector 13, that is, the waveform of the emission intensity I, as shown in FIG. A detection element extractor 29 to be transmitted, and an average value and a variance of calculating the average value m and the variance value σ ² from the emission intensity I (see FIG. 5) sequentially extracted by the detection element extractor 29 and transmitting each of them. Value calculator 30, the average value m received from the average value / variance value calculator 30, and the emission intensity I received from the detection element extractor 29.
And a calculator 31 for calculating and transmitting the difference between
1 and a variance value σ ² received from the average / variance value calculator 29, and a comparator 32 for transmitting the comparison result, and a comparator 32 for receiving the comparison result. A determination unit 33 that determines a point in time when the absolute value of the comparison value exceeds a predetermined reference value as an end point of the etching, and transmits a determination result of the determination unit 33 to the controller 15 as described above; The high frequency power supply 6 and the like are controlled via the control unit to control the etching process.

[0016] In the arithmetic processing unit 13, first, the average value and dispersion value calculating unit 3 the mean value m and variance sigma ² of the emission intensity I of the plasma 8 in the initial predetermined time etching T ₁
The variation of the light emission intensity I due to the amount of the etching gas or the electric noise during the etching process is statistically grasped. Next, the initial predetermined time T ₁
After the elapse, the difference between the light emission intensity I and the average value m, which fluctuates with time, is calculated by the calculator 31. Then, the absolute value of the difference value and the variance σ ² are compared by the comparator 32. Is determined by the determiner 33 as the end point of the etching when the value exceeds the reference value.

The initial predetermined time T ₁ of the etching in end point detection described above, the time that can be set arbitrarily within a certain time before ending the etching from the time when etching is started, as such a time It is possible to set a time within a range common to various etching processes without being influenced by various etching process conditions. Then, the average value m and the variance σ ² of the waveform of the light emission intensity I fluctuating within the initial predetermined time T ₁ are obtained at the time when the initial predetermined time T _{1 has} elapsed, so that the time variation of the light emission intensity I during the etching process is obtained. Can be grasped at the beginning of etching. When the difference between the emission intensity I and the average value m is compared with the variance σ ² after the initial predetermined period has elapsed, the standard deviation σ of the variance σ ² is used when the difference is directly compared with the difference. Then, the point when the comparison value exceeds the reference value after the elapse of the initial predetermined period can be regarded as the end point of the etching process. That is, the average value m and the variance value σ ² calculated each time according to each etching condition as described above can be used as the reference value when the end point is determined by the determiner 33, that is, the threshold value.

Next, the operation will be described. For example, 0.
A semiconductor wafer 3 coated with a silicon oxide film is placed on a lower electrode 4 in a processing chamber 1 in which a vacuum state of 1 mTorr to several Torr is formed.
When an etching gas containing F ₄ as a main component is introduced, and then high frequency power is applied to the lower electrode 4 from the high frequency power supply 6 via the blocking capacitor 5, a vacuum discharge occurs between the lower electrode 4 and the upper electrode 7. Then, CF ₄ or the like is turned into plasma, and the silicon oxide film of the semiconductor wafer 3 is etched by the active species to generate SiF ₄ and a CO gas to be monitored for etching. When each emission spectrum of the active species such as CO ^* returns to the ground state, passes through the monitoring window 10 of the processing chamber 1, the transmitted light is collected by the lens 12 to the photodetector 13. After detecting the light, the photodetector 13 disperses the emission spectrum of CO ^* (483.5 nm or the like) from the detected light, and then converts the electric signal of the emission intensity I photoelectrically converted into a data signal as the end-point calculator 1.
Send to 4.

Upon receiving the data signal, the end point arithmetic unit 14 performs the following processing internally. That is, first, when the detection element extractor 29 of the end point arithmetic unit 14 receives a data signal as input data (step 1), the detection element extractor 2
And extracted input data based on the emission intensity I from the input data received at 9 (step 2) after the reception is judged whether or not within the initial predetermined time T ₁ of the etching (step 3), the initial predetermined time if within T ₁ sequentially transmitted to the average value and dispersion value calculating unit 30, wherein after performing only storage of these input data, sequentially stores the input data by repeating the series operation returns to step 1 ( Step 4). On the other hand, the initial predetermined time proceeds to step 5 if judged not to be the T within ₁ Step 3, it is determined whether the time of reaching just to the initial predetermined time T _1, is just the end of the initial predetermined time T ₁ Is determined, the emission intensity I is immediately determined based on the input data accumulated by the average value / variance value calculator 30.
Of the average value m and the variance value σ ² of
(Step 6) and return to Step 1. And
If it is determined that has elapsed initial predetermined time T ₁ at step 5, the calculator 3 from the average value and dispersion value calculating unit 30 at that time
1 and the average value m and the variance value σ ² to the comparator 32, respectively. The arithmetic unit 31 stores the average value m, calculates the difference between the input data sequentially received from the detection element extractor 29 and the average value m (step 7), and transmits the difference value to the sequential comparator 32. . The comparator 32 successively compares the already stored variance value σ ² (more specifically, the standard deviation σ) with the value of this difference (step 8), and transmits the result to the determiner 33. The determiner 33 sequentially determines whether or not the absolute value of the difference exceeds a reference value based on the comparison results sequentially received (step 9), and if not, returns to step 1 and repeats the determination. If it is determined in step 9 that the absolute value exceeds the reference value, the control signal is transmitted to the controller 15 assuming that the end point of the etching has been reached, and the etching process is terminated.

However, at the time of the above-described etching, the gas generated in the processing chamber 1 is filled with the gas in the opening 16 of the processing chamber 1.
Flows through the cylindrical body 17 toward the monitoring window 10. When this gas flows out of the opening 16 into the cylinder 17,
The stenosis member 23 in the middle acts on the gas from the processing chamber 1 to restrict the gas flow to the monitoring window 10, and traps a part of the gas in the first trap unit 25. Further, when gas flows from the cylindrical portion 27 of the constriction member 23 into the second trap portion 25, the gas flow is rapidly reduced because the second trap portion 25 is larger than the cylindrical portion 27, and the second trap portion 25 is enlarged. The gas diffuses into the trap portion 25, traps the gas in the second trap portion 25, and a part of the gas that has passed through the narrowing member 23 is
0 on the transparent glass 21. Then, each time the etching of the semiconductor wafer 3 is repeated, the generated gas in the processing chamber 1 repeatedly flows out into the cylindrical body 17. At this time, the inflowing gas is transferred to the first and second trap portions 2 in the cylindrical body 22 as described above.
Since trapping is gradually performed at 4 and 25, the amount of generated gas reaching the monitoring window 10 can be significantly reduced as compared with the conventional case, and the deposition of generated gas on the transparent glass 21 can be significantly suppressed.

As described above, according to the present embodiment, the cylindrical body 17 is connected to the opening 16 formed in the peripheral wall 9 of the processing chamber 1 by protruding from the outer peripheral surface of the cylindrical body 17. 10 and a peripheral wall 9 and a monitoring window 10 in a cylindrical body 17.
Between the first trap portion 24 and the second trap portion 24.
The stenosis member 23 partitioned into the trap portion 25 is not provided .
The constriction member 23 extends from the central hole of the annular portion 26 to the peripheral wall 2.
6 has a tubular portion 27 continuously provided as a stenosis portion, so that the stenosis member 23 is formed in the tubular body 17.
Generated stepwise in the first and second trap units 24 and 25
The gas is trapped , the generated gas is prevented from adhering to the transparent glass 21 of the monitoring window 10, the number of times of etching of the semiconductor wafer 3 is increased, and the transparency of the transparent glass 21 is maintained for a longer time than in the past. The cleaning interval of the transparent glass 21 can be lengthened, the number of times of cleaning of the apparatus itself can be reduced, and the operation efficiency of the apparatus can be enhanced. In this embodiment, the cylinder 1
7 is provided with a temperature control mechanism 28 having a cooling means, thereby promoting the gas adhesion to the first and second trap portions 24 and 25 to suppress the amount of gas reaching the monitoring window 10, or Second trap units 24 and 25 and monitoring window 10
By suppressing the adhesion of gas at the above, the adhesion of gas to the monitoring window 10 can be further suppressed.

The present invention is also applicable to a multi-chamber processing apparatus having a plurality of plasma processing chambers. And in the case of this multi-chamber processing apparatus, the etching processing in a plurality of processing chambers can be monitored by one arithmetic unit. When a plurality of, for example, three processing chambers are monitored by one end point detection device, the end point detection devices can be configured in three types as follows, for example. As shown in FIG. 7, one of the end point detection devices combines only the user interface among the three components conventionally provided individually, such as a spectroscope, a controller, an input device, and an output device. The second is FIG.
As shown in Fig. 9, the user interface and the controller of the three components are combined into one, and the third is to combine all three components into one as shown in Fig. 9. It is configured. Needless to say, the monitoring window of the present invention is attached to each processing chamber constituting the multi-chamber processing apparatus, so that the number of times of cleaning of the multi-chamber processing apparatus is reduced, that is, the operation efficiency is improved. By applying such an end point detection device to a multi-chamber processing apparatus, all the processing chambers 41 can be monitored collectively by one end point detection device.

As shown in FIG. 7, an end point detection device having only one user interface has three processing chambers 4.
For example, three spectroscopes 42 individually connected to each other by, for example, optical fibers, three controllers 43 individually electrically connected to each of the spectrometers 42, and one spectrometer electrically connected to each of the controllers 43, respectively. And two user interfaces 44.
Therefore, in the case of this end point detection device, the emission spectrum from each processing chamber 41 is separated into a light emission spectrum having a specific wavelength by each spectroscope 42, and the separated light signal is photoelectrically converted. It transmits to each controller 43. Each controller 43 creates a digital signal by A / D conversion of each input signal.
Each digital signal is subjected to predetermined processing and transmitted to one user interface 44. The user interface 44 that has received each digital signal displays an image or the like as a waveform based on each digital signal. This display allows the observer to individually monitor the processing status such as etching in each processing chamber 41. As a display method, for example, there is a method of performing batch display by multi-window processing or a method of performing individual display by selection processing.

An end point detection device that combines a user interface and a controller as shown in FIG.
Three spectrometers 42 individually connected to the three processing chambers 41 by optical fibers, and one controller 43 individually and electrically connected to each spectrometer 42
And one user interface 44 electrically connected to the controller 43. Therefore, in the case of this end point detecting device, each processing chamber 4
The spectroscope 42 splits the emission spectrum from 1 into an emission spectrum exhibiting a specific wavelength, converts the split optical signal into a photoelectric signal, and transmits the electrical signal to the controller 43. The controller 43 A / D converts each input signal in a time-division manner or in parallel to generate a digital signal, performs predetermined processing on each digital signal, and transmits each digital signal to one user interface 44 in a serial or parallel manner. I do. The user interface 44 that receives each digital signal displays each digital signal serially or in parallel as a waveform on an image or the like. The observer can use this display to display each processing room 41.
Process conditions such as etching can be monitored individually.

FIG. 9 shows an end-point detection device that combines a user interface, a controller, and a spectroscope.
As shown in FIG. 7, one spectroscope 42 connected to each of the three processing chambers 41 by an optical fiber,
2 and one user interface 44 electrically connected to the controller 43. Then, the emission spectrum from each processing chamber 41 is
As a method of transmitting the light to the processing unit 41, the incident part is divided into three parts according to the processing chamber 41, and each of the incident parts is transmitted to the spectroscope 42 using a branch fiber allocated to the processing chamber 41, or an individual part is transmitted. There is a method in which an optical signal transmitted via an optical fiber is switched to an optical signal in a time division manner using an optical switch such as a half mirror or a rotating sector and transmitted to the spectroscope 42. Further, the processing chamber 41 is controlled by the spectroscope 42.
As a method of detecting the intensities of the three types of light transmitted from each other, for example, the light from each processing chamber 41 is modulated by a carrier wave, these are mixed and transmitted to the spectroscope 42, and the There is a method in which a transmission signal is detected and rectified and transmitted to the controller 43 as individual light intensity. In this case, signals from the processing chambers 41 may be distinguished by using different frequencies for the carrier waves from the individual processing chambers 41 or using different phases at the same frequency. As a method of producing a carrier wave, for example, there is a method of blocking light with a shutter or the like used for a chopper or a camera. As a detection method, there is a detection method using hardware such as a lock-in amplifier and a box car integrator, or a detection method using software. At this time, the signal may be extracted in a time-division manner in synchronization with the carrier wave.

It should be noted that the present invention is not limited to the above embodiment at all, and the forms of the cylindrical member and the constricted portion can be appropriately changed as needed. Further, the present invention is not limited to a plasma etching apparatus,
It can be widely applied to VD devices, ashing devices, and the like.

[0027]

As described above, according to the first aspect of the present invention, plasma is generated in the processing chamber.
A plasma processing unit configured to perform plasma processing on the object to be processed with the plasma, detect an emission intensity of plasma transmitted through a monitoring window provided in the processing chamber, and monitor the plasma processing based on the detected value; in the apparatus, the outer end of the cylindrical body with connecting by projecting the cylindrical body to the opening formed in the peripheral wall of the processing chamber provided with a monitoring window and the peripheral wall of the processing chamber into the cylinder body and the it is provided the location constricting member for partitioning the cylinder body and the second trap portion first trap portion between the monitoring window, the constriction member is in the peripheral wall of the processing chamber from the central bore Since it has a cylindrical portion continuously provided as a constriction portion, the generated gas is trapped in a stepwise manner by first and second trap portions formed through a constriction member in the cylinder , and the first trap portion is formed. In the second trap section To limit the flow rate of the product gas that,
It is possible to provide a plasma processing apparatus in which the generated gas is prevented from adhering to the transparent glass of the monitoring window, the number of times of the plasma processing of the object to be processed is increased, and the operation efficiency of the apparatus is improved.

[0028] According to the invention described in claim 2 of the present invention, in the invention described in claim 1, for providing a temperature adjusting mechanism having at least cooling means to said cylindrical body, through the cooling means cylinder the first longitudinal constriction member of the cylinder body by cooling the body to promote adhesion of the product gas in the second trap portion, the product gas by increasing the trapping volume of the product gas of the monitor window to a transparent glass It is possible to provide a plasma processing apparatus capable of suppressing the adhesion of the plasma.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a plasma processing apparatus of the present invention.

FIG. 2 is an exploded perspective view showing a monitoring window portion of the plasma processing apparatus shown in FIG.

FIG. 3 is a sectional view showing a relationship between a monitoring window and a processing chamber shown in FIG.

FIG. 4 is a block diagram illustrating a configuration of a main part of the end point detection device illustrated in FIG. 1;

FIG. 5 is a graph illustrating the operation of the end point detection device shown in FIG.

FIG. 6 is a flowchart showing a flow of end point detection in a preferred embodiment of the end point detection method of the present invention using the etching end point detection device shown in FIG. 1;

FIG. 7 is a configuration diagram illustrating an example of an end point detection device of a multi-chamber processing apparatus including three processing chambers illustrated in FIG.

8 is a configuration diagram illustrating another example of the end point detection device of the multi-chamber processing apparatus including the three processing chambers illustrated in FIG.

9 is a configuration diagram illustrating still another example of the end point detection device of the multi-chamber processing apparatus including the three processing chambers illustrated in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Processing chamber 3 Semiconductor wafer (object to be processed) 4 Lower electrode 7 Upper electrode 9 Peripheral wall 10 Monitoring window 16 Opening 17 Cylindrical body (cylindrical member) 21 Transparent glass (Monitoring window) 23 Narrowed part 28 Temperature control mechanism

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/3065 C23F 4/00

Claims (2)

(57) [Claims] 1. A plasma is generated in a processing chamber, an object to be processed is subjected to plasma processing by the plasma, and an emission intensity of plasma transmitted through a monitoring window provided in the processing chamber is detected. In a plasma processing apparatus configured to monitor the plasma processing, a cylindrical body is projected and connected to an opening formed in a peripheral wall of the processing chamber, and a monitoring window is provided at an outer end of the cylindrical body , And above
It is provided the location constricting member for partitioning the cylinder body and the second trap portion first trap portion between the peripheral wall and the monitoring window of the processing chamber into the cylinder body, the constriction member is A plasma processing apparatus comprising: a tubular portion continuously provided as a constricted portion from a central hole toward a peripheral wall of the processing chamber . 2. The plasma processing apparatus according to claim 1, wherein a temperature adjusting mechanism having at least a cooling unit is provided in the cylindrical body .