JP3878746B2 - Semiconductor manufacturing condition setting method, semiconductor manufacturing condition setting apparatus, semiconductor manufacturing apparatus using this apparatus, and condition setting method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor manufacturing process such as plasma etching, sputtering, plasma CVD or the like (hereinafter referred to as “plasma process”) in which a substrate to be processed is processed using plasma generated in a chamber using high-frequency power. The present invention relates to a method and apparatus for setting various conditions such as high-frequency power, a semiconductor manufacturing apparatus using the apparatus, and a semiconductor substrate manufactured using the semiconductor apparatus.
[0002]
[Prior art]
Conventionally, a plasma process using plasma is known among semiconductor manufacturing processes. In order to perform this plasma process efficiently, it is necessary to set the high-frequency power for generating plasma, the pressure in the chamber, the flow rate of the etching gas flowing into the chamber, etc. to predetermined values. The parameters such as the high-frequency power, the pressure in the chamber, and the gas flow rate are monitored by a high-frequency power meter, an in-container pressure meter, a gas flow meter, and the like attached outside the semiconductor manufacturing apparatus, respectively.
[0003]
According to these instruments, the magnitude of each parameter given from the outside of the chamber during the plasma process, specifically, the high frequency power applied from the high frequency generator to the high frequency electrode in the chamber, the exhaust valve to the chamber The internal pressure of the container after the internal gas is discharged, the flow rate of the gas flowing into the chamber through the gas introduction valve, and the like can be measured.
[0004]
[Problems to be solved by the invention]
However, in the semiconductor manufacturing apparatus in the plasma process, the decomposition product of the processing material generated in the process adheres to the inner wall surface of the chamber and the high-frequency electrode, causing an impedance change with respect to the high-frequency power supplied from the high-frequency generator. As a result, the effective power used for the reaction fluctuates, and the pressure in the container fluctuates as the vacuum holding material deteriorates. Furthermore, due to the rapid and large inflow of gas that occurs when the gas introduction valve is opened and the opening and closing error of the gas introduction valve, the gas inflow amount and the gas mixture ratio in the vicinity of the substrate to be processed such as a wafer, etc. It will fluctuate. Variations in parameters such as effective power and pressure inside the container may lead to product quality degradation, for example, the direction of etching does not become the desired direction in plasma etching, or the film quality does not change or become uniform in plasma CVD. become.
[0005]
Such fluctuations in parameters cannot be measured by various instruments such as a high-frequency wattmeter attached outside the semiconductor manufacturing apparatus. Therefore, even though various instruments show desired values, A situation occurs where the value is different from the desired value. The occurrence of such a situation cannot be detected by various external instruments, so that the semiconductor manufacturing process continues even though the plasma process is not performed normally, and the material after the process ends Even if an abnormality of a semiconductor manufacturing apparatus is noticed due to a defect, the parameter that caused the defect in the material is not known, and thus a method for recovering the apparatus cannot be found.
[0006]
As described above, the status of each parameter affecting the progress of the plasma process is monitored by an instrument attached to the outside of the chamber, such as a high-frequency power meter, an in-vessel pressure gauge, and a gas flow meter. The value of the changing parameter cannot be grasped, and it becomes difficult to perform a stable plasma process by the semiconductor manufacturing apparatus.
[0007]
The present invention has been made in view of such circumstances, and by grasping changes in parameters that cannot be measured by an external instrument, a semiconductor plasma process can be performed in a stable state, and a high-quality semiconductor is manufactured. An object of the present invention is to provide a semiconductor manufacturing condition setting method, a semiconductor manufacturing condition setting apparatus, a semiconductor manufacturing apparatus using the apparatus, and a semiconductor substrate manufactured by the semiconductor manufacturing apparatus.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a semiconductor manufacturing condition setting method according to claim 1 is a method for setting manufacturing conditions of a semiconductor manufacturing process in which processing is performed on a substrate to be processed using plasma generated in a chamber. A step of generating fluorescence by irradiating plasma with excitation light, a step of splitting the fluorescence, a step of calculating the fluorescence intensity of each wavelength of the divided fluorescence, and a plurality of parameters as manufacturing conditions. A step of selecting, for each parameter, at least two or more wavelengths as corresponding wavelengths from among the wavelengths in which the fluorescence intensity changes in accordance with the increase or decrease of the parameter when the value is increased or decreased, and the parameter valueWhether the fluorescence intensity at each corresponding wavelength increases, decreases, or remains unchanged when the value increases or decreasesGenerating a reference fluorescence data for each parameter, determining a permissible fluorescence range corresponding to the permissible range of the parameter based on the fluorescence intensity of each corresponding wavelength for each parameter, and a substrate to be processed The process calculates the fluorescence intensity during processing, which is the fluorescence intensity of each corresponding wavelength of the fluorescence obtained when processing is performed, and based on the reference fluorescence data, candidate parameters corresponding to the fluorescence intensity during processing are selected from the parameters. And a step of adjusting the value of the candidate parameter until the value based on the fluorescence intensity during processing falls within the allowable fluorescence range when the value based on the fluorescence intensity during processing exceeds the allowable fluorescence range. It is characterized by.
[0009]
According to the semiconductor manufacturing condition setting method of the first aspect of the invention, first, fluorescence is emitted from particles contained in the plasma in the chamber by irradiation of the plasma with excitation light. For example, the fluorescence is dispersed by a diffraction grating or the like, and the dispersed fluorescence is received by a linear image sensor or the like, and the fluorescence intensity at each wavelength is calculated. Some of the wavelengths of the dispersed fluorescence change when the value of a parameter such as high-frequency power is increased or decreased, and the fluorescence intensity changes in accordance with the change of the parameter, but this fluorescence intensity changes. At least two or more wavelengths are selected as the corresponding wavelengths from the wavelengths. The selection of the corresponding wavelength is performed for each parameter, that is, for each parameter such as high-frequency power and gas flow rate.
[0010]
After the corresponding wavelength is selected, reference fluorescence data indicating the relationship between the parameter value and the fluorescence intensity of each corresponding wavelength is created for each parameter. While the reference fluorescence data is created, an allowable fluorescence range that is a range based on the fluorescence intensity of each corresponding wavelength corresponding to the allowable range of the parameter is also determined. Here, the allowable range of the parameter will be described. When the parameter is out of the desired range (abnormal value), the substrate to be processed that has undergone the semiconductor manufacturing process does not perform the intended function. Considering a sufficient margin is an allowable range of parameters. The desired range of parameters means an ideal range in the case where no problem occurs in the substrate to be processed after the semiconductor manufacturing process.
[0011]
After the allowable fluorescence range for each parameter is calculated, the in-process fluorescence intensity, which is the fluorescence intensity of each corresponding wavelength of the fluorescence generated from the plasma that is actually processed on the target substrate and irradiated with excitation light, is obtained. Calculated. Then, based on the reference fluorescence data, candidate parameters corresponding to the in-process fluorescence intensity are selected from several types of parameters. Further, when the in-process fluorescence intensity exceeds the allowable fluorescence range, the value of the candidate parameter is adjusted until the in-process fluorescence intensity falls within the allowable fluorescence range, and each parameter in the chamber is set near the desired range. Can be maintained. Thereby, a semiconductor manufacturing process can be performed in a stable state.
[0012]
According to a second aspect of the present invention, in the semiconductor manufacturing condition setting method according to the first aspect, the parameters include a high frequency power for generating plasma, a frequency for generating plasma, and ions or radicals contained in the plasma. At least one of a bias voltage for inducing toward the processing substrate, a flow rate of a gas flowing into the chamber, a pressure in the chamber, a magnetic field strength for maintaining a high density of plasma, or a temperature in the chamber It is characterized by being.
[0013]
  A semiconductor manufacturing condition setting device according to a third aspect of the invention is an apparatus for setting manufacturing conditions of a semiconductor manufacturing process in which processing is performed on a substrate to be processed using plasma generated in a chamber, wherein excitation light is emitted. Excitation light generating means for outputting, spectroscopic means for dispersing fluorescence emitted from particles in plasma by irradiation of excitation light, having resolution in the fluorescence spectral direction, and receiving each wavelength component of the dispersed fluorescence A light detection means for outputting an electrical signal corresponding to the intensity of each wavelength of the fluorescence, a fluorescence intensity calculation means for calculating the fluorescence intensity of each wavelength of the fluorescence based on the electrical signal output from the light detection means, and manufacturing When changing the values of a plurality of parameters, which are conditions, at least two or more wavelengths are selected as the corresponding wavelengths from among the wavelengths at which the fluorescence intensity changes with the increase / decrease in the parameters. The corresponding wavelength selection means for selecting for each data, the value of the parameterWhether the fluorescence intensity at each corresponding wavelength increases, decreases, or remains unchanged when the value increases or decreasesA reference fluorescence data creation means for creating reference fluorescence data for each parameter, and an allowable fluorescence range corresponding to the allowable range of the parameter based on the fluorescence intensity of each corresponding wavelength of fluorescence is determined for each parameter. Based on the reference fluorescence data, the allowable fluorescence range determining means for calculating, the in-process fluorescence intensity calculating means for calculating the in-process fluorescence intensity that is the fluorescence intensity of each corresponding wavelength of the fluorescence obtained when processing the substrate to be processed, and Candidate parameter selection means for selecting candidate parameters according to the fluorescence intensity during processing from among the parameters;In addition to transmitting a pulse timing signal for making the excitation light pulse excitation light to the excitation light generating means, and in synchronization with the pulse timing signal, from the time when a predetermined light reception stop time has elapsed after the output of one pulse excitation light Timing signal generating means for generating a first light receiving timing signal for instructing a predetermined time until the time before the next pulse excitation light is output, and the light detecting means is based on the first light receiving timing signal. , Light can be received for a predetermined timeIt is characterized by that.
[0014]
According to the semiconductor manufacturing condition setting apparatus of the third aspect, the fluorescence is emitted from the particles contained in the plasma in the chamber by the irradiation of the excitation light output from the excitation light generating means. This fluorescence is separated by a spectroscopic means such as a diffraction grating. Further, the dispersed fluorescence is detected by a light detection unit having resolution in the fluorescence spectral direction, and the light detection unit outputs an electrical signal corresponding to the intensity of each wavelength of the fluorescence. The fluorescence intensity calculation means that receives the electrical signal emitted from the light detection means calculates the fluorescence intensity at each wavelength of fluorescence based on this electrical signal. Among each wavelength of the separated fluorescence, when the value of a parameter such as high-frequency power is increased or decreased, the fluorescence intensity changes with the change of the parameter. At least two or more wavelengths are selected as the corresponding wavelengths from the wavelengths at which the fluorescence intensity changes. The selection of the corresponding wavelength is performed for each parameter, that is, for each parameter such as high-frequency power and gas flow rate.
[0015]
After the corresponding wavelength is selected, the reference fluorescence data creating means creates the reference fluorescence data indicating the relationship between the parameter value and the fluorescence intensity of each corresponding wavelength for each parameter. While the reference fluorescence data is created, the tolerance range determining means determines the tolerance fluorescence range that is a range based on the fluorescence intensity of each corresponding wavelength corresponding to the tolerance range of the parameter. After the allowable fluorescence range is determined for each parameter, the substrate to be processed is actually processed, and the fluorescence at each corresponding wavelength of the fluorescence generated from the plasma irradiated with the excitation light by the processing fluorescence intensity calculation means The in-process fluorescence intensity, which is the intensity, is calculated. A candidate parameter selection unit selects a candidate parameter corresponding to the in-process fluorescence intensity from several types of parameters based on the reference fluorescence data.
[0016]
  After the candidate parameter is selected, the reference fluorescence data of the candidate parameter is displayed on a display, for example. When the fluorescence intensity during processing exceeds the allowable fluorescence range, the operator adjusts the value of the candidate parameter by operating various instruments such as a high-frequency generator, and keeps the fluorescence intensity during processing within the allowable fluorescence range. . As a result, the parameters in the chamber can be set and maintained in the vicinity of the desired range, and the semiconductor manufacturing process can proceed in a stable state.
The pumping light generating unit receives the pulse timing signal transmitted from the timing signal generating unit, thereby converting the pumping light into pulse pumping light. Further, the timing signal generation means generates a first light reception timing signal indicating a predetermined time in synchronization with the pulse timing signal. Then, based on the first light reception timing signal, the light detection means is in a light reception enabled state for the predetermined time and receives fluorescence or the like. Here, in general, particles excited by receiving excitation light relax and emit fluorescence after a while from the time of excitation light irradiation, but the light detection means in the present invention enters a light receiving state, This is after a predetermined light reception stop time has elapsed since the output of one pulsed excitation light. For this reason, the light detection means is in a state where it can receive light when a large amount of fluorescence is generated from the plasma, and can efficiently receive the fluorescence emitted from the particles in the plasma.
[0017]
According to a fourth aspect of the present invention, in the semiconductor manufacturing condition setting apparatus according to the third aspect, the parameter value control means for controlling the value of the candidate parameter by receiving the control signal, and the value based on the in-process fluorescence intensity is an allowable fluorescence. It further comprises parameter value setting means for transmitting a control signal to the parameter value control means until the value based on the in-process fluorescence intensity falls within the allowable fluorescence range when the range is exceeded.
[0018]
According to the semiconductor manufacturing condition setting device of the invention described in claim 4, when the value based on the fluorescence intensity during processing exceeds the allowable fluorescence range, the value based on the fluorescence intensity during processing is set to the allowable fluorescence by the parameter value setting means. A control signal is transmitted to the parameter value control means until it falls within the range. When the control signal reaches the parameter value control means, the parameter value control means controls the value of the candidate parameter. Thereby, the candidate parameter in the chamber can be automatically set and maintained in the vicinity of the desired range, and the semiconductor manufacturing process can be performed in a stable state.
[0019]
According to a fifth aspect of the present invention, in the semiconductor manufacturing condition setting apparatus according to the third aspect, the parameters are a high frequency power for generating plasma, a frequency for generating plasma, and ions or radicals contained in the plasma. At least one of a bias voltage for inducing toward the processing substrate, a flow rate of a gas flowing into the chamber, a pressure in the chamber, a magnetic field strength for maintaining a high density of plasma, or a temperature in the chamber It is characterized by being.
[0022]
  Claim6The described invention is claimed.3In the semiconductor manufacturing condition setting device described above, the timing signal generation means further generates a second light reception timing signal that indicates the same time as the predetermined time when the excitation light generation means is in an output stop state of the excitation light. The light detection means is in the first light receiving state for the predetermined time based on the first light receiving timing signal and can receive the second light only for the same time as the predetermined time based on the second light receiving timing signal. The fluorescence intensity calculation means is based on the difference between the electrical signal output from the light detection means in the first light-receiving ready state and the electrical signal output from the light detection means in the second light-receiving ready state, The fluorescence intensity is calculated.
[0023]
  Claim6According to the semiconductor manufacturing condition setting apparatus according to the invention described above, the light detection means in the first light reception enabled state receives the fluorescence that is the detection target and the plasma light that is noise based on the first light reception timing signal. . Further, a second light receiving timing for instructing the same time as the predetermined time by the timing signal generating means when the excitation light generating means is in an output stop state of the excitation light, that is, when no fluorescence is emitted from the plasma. A signal is generated. The light detecting means that has received the second light receiving timing signal is in a second light receiving enabled state and receives only plasma light. Then, the fluorescence intensity calculating means detects noise by taking a difference between the electric signal output from the light detecting means in the first light receiving ready state and the electric signal output from the light detecting means in the second light receiving ready state. The emission intensity of a certain plasma light can be removed, and the intensity of only fluorescence can be calculated.
[0024]
  Claim7The invention described is a semiconductor manufacturing apparatus for manufacturing a semiconductor substrate by generating plasma in a chamber and processing the substrate to be processed using the plasma.6The semiconductor manufacturing condition setting device according to claim 1, wherein the chamber has an incident window for allowing the excitation light to enter the chamber, and plasma emission and fluorescence in the chamber are emitted to the outside. The spectroscopic means of the semiconductor manufacturing condition setting device is arranged at a position where plasma light and fluorescence that have passed through the monitoring window are incident.
[0025]
  Claim7According to the semiconductor manufacturing condition setting apparatus according to the described invention, the chamber is provided with the incident window for allowing the excitation light to enter, and the excitation light enters the plasma from the incident window. The chamber is provided with a monitoring window for emitting fluorescence and plasma light to the outside, and the fluorescence passing through the monitoring window is incident on the spectroscopic means of the semiconductor manufacturing condition setting apparatus. After the fluorescence is incident on the spectroscopic means, the value of each parameter is set and maintained in the vicinity of the desired range by the semiconductor manufacturing condition setting device, and the semiconductor manufacturing process can proceed in a stable state.
[0026]
  Claim8The described invention is claimed.7The semiconductor manufacturing apparatus described above is characterized in that at least one of the incident window and the monitoring window is provided with anti-fogging means.
[0027]
  Claim8According to the semiconductor manufacturing apparatus according to the described invention, the fogging means prevents fogging of the incident window and the monitoring window, so that it is possible to efficiently irradiate the excitation light to the plasma and to enter the fluorescence into the spectroscopic means. it can.
[0028]
  Claim9The described invention is claimed.8In the semiconductor manufacturing apparatus described above, the anti-fogging means is a heater that heats at least one of the incident window and the monitoring window.
[0029]
  Claim9According to the semiconductor manufacturing apparatus according to the described invention, since the incident window and the monitoring window are heated by the heater, reaction products such as reactive ions moving from the center of the chamber are less likely to adhere to the incident window and the monitoring window. , Fogging of these windows is prevented.
[0030]
  Semiconductor substrateClaims7~ Claim9A process is performed by the semiconductor manufacturing apparatus according to any one of the above.
[0031]
  the aboveSince the semiconductor substrate is manufactured in a state in which the candidate parameters in the chamber are maintained in the vicinity of the desired range, for example, processing such as etching is performed with high accuracy and high quality.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a semiconductor manufacturing condition setting method, a semiconductor manufacturing condition setting apparatus, a semiconductor manufacturing apparatus using the apparatus, and a semiconductor substrate manufactured by the semiconductor manufacturing apparatus according to the present invention will be described in detail. In addition, the same code | symbol shall be used for the same element or the element which has the same function, and the overlapping description is abbreviate | omitted.
[0033]
(First embodiment)
FIG. 1 shows the overall configuration of a semiconductor manufacturing apparatus 2 according to the first embodiment. As shown in the figure, the semiconductor manufacturing apparatus 2 of this embodiment is equipped with a semiconductor manufacturing condition setting apparatus 4. The semiconductor manufacturing apparatus 2 according to the present embodiment is a plasma dry etching apparatus that generates plasma in the chamber 6 to etch the silicon wafer 7 that is the substrate to be processed.
[0034]
The substantially cylindrical chamber 6 made of quartz or the like has an etching gas CHF._Three, CF_Four, Ar or the like is introduced into the chamber 6 and a gas introduction port 8 for inserting an etching gas inflow amount is provided in the gas introduction port 8. . The chamber 6 is inserted with an exhaust port 10 for causing the gas in the chamber 6 to flow out to reduce the pressure, and the exhaust port 10 has an exhaust valve 10a for adjusting the outflow amount of the gas. Is provided.
[0035]
Inside the chamber 6, an upper electrode 12 a and a lower electrode 12 b that supports the wafer 7 are disposed to face each other. The upper electrode 12 a has a frequency for generating plasma 13 and a high frequency that generates electric power. A generator 14 is connected, and a bias power supply 16 for supplying a bias voltage for inducing ions or radicals contained in the generated plasma to the lower electrode 12b is connected to the lower electrode 12b. A temperature regulator 18 for adjusting the temperature in the chamber 6 is disposed below the lower electrode 12b. Further, an annular magnet coil 20 is provided on the outer periphery of the chamber 6. The magnet coil 20 forms a magnetic field for trapping plasma in the chamber 6 and generates and maintains high-density plasma.
[0036]
Further, a cylindrical protrusion 22 that protrudes to the outside is formed on a part of the outer peripheral surface of the chamber 6 (on the right side in FIG. 1), and plasma light can be transmitted through the tip of the protrusion 22. A monitoring window 24 made of non-fluorescent glass is fitted. Further, a ring-shaped heater 26 as anti-fogging means is disposed on the outer periphery of the protrusion 22 so as to cover this outer periphery. The heater 26 is for heating the monitoring window 24, and by making the temperature of the monitoring window 24 higher than the surrounding protrusion 22, reaction of reactive ions or the like moved from the plasma 13 in the chamber 6. The product is less likely to adhere to the monitoring window 24 and fogging of the monitoring window 24 is prevented.
[0037]
In addition, in order to prevent the monitoring window 24 from being fogged, the monitoring window 24 is not heated by the heater 26, but an electrode is provided to create a potential gradient so that reactive ions do not approach the monitoring window 24. A configuration can also be employed. FIG. 2 shows an example using electrodes. In the configuration of FIG. 2A, the mesh electrode 26a is arranged in the projecting portion 22 in parallel with the monitoring window 24. When a voltage is applied to the mesh electrode 26a, reactive ions are adsorbed on the mesh electrode 26a. Either does not reach the monitoring window 24 or is repelled by the mesh electrode 26a and moves away from the monitoring window 24. Thereby, fogging of the monitoring window 24 is prevented. In the configuration of FIG. 2B, the annular electrode 26 b is disposed on the outer periphery of the protruding portion 22. When a voltage is applied to the annular electrode 26b, the reactive ions are attracted to the annular electrode 26b and adsorbed on the inner peripheral surface of the projecting portion 22 or are prevented from moving in the direction of the monitoring window 24. For this reason, the reactive ions do not reach the monitoring window 24 and fogging of the monitoring window 24 is prevented.
[0038]
Next, the configuration of the semiconductor manufacturing condition setting device 4 will be described with reference to FIGS. 1 and 3. 3 is a cross-sectional view of the chamber 6 shown in FIG. 1 taken along the line III-III. As shown in FIG. 3, the semiconductor manufacturing condition setting device 4 of this embodiment includes a pulsed laser light source 5 that outputs pulsed excitation light. Particles such as atoms, molecules, ions or radicals in the plasma 13 are excited by the pulsed excitation light output from the laser light source 5. Note that a protrusion 23 is formed at a position of the chamber 6 where the pulse laser light source 5 is mounted, and an incident window 25 for allowing excitation light to enter is fitted into the protrusion 23. Further, a fogging preventing heater 27 for heating the incident window 25 is disposed around the protrusion 23. As described above, it is naturally possible to use an electrode instead of the heater 27 as the anti-fogging means. Further, an optical trap 9 for stopping the pulse excitation light is disposed at a position facing the laser light source 5 on the inner wall of the chamber 6.
[0039]
Particles such as ions emit fluorescence when relaxed after being excited by excitation light for a while. The pulse laser light source 5 is a parametric wavelength tunable laser including a nonlinear optical crystal such as a BBO crystal and a harmonic generator, and the wavelength of the excitation light can be changed from 220 nm to 450 nm by changing the angle of the BBO crystal. it can. In addition, the laser which can be used is not restricted to this laser, The laser which outputs the laser beam of another wavelength range can also be used naturally. As shown in FIG. 1, the semiconductor manufacturing condition setting device 4 includes a timing signal generator 11 that generates a pulse timing signal, and the pulse laser light source 5 is output from the timing signal generator 11. The pulse excitation light is output in synchronization with the pulse timing signal. The timing signal generator 11 that generates the pulse timing signal may be built in the laser light source 5. In addition, as another method for converting the excitation light into a pulse, there is a method using a chopper in which a light passing portion that allows the excitation light to pass and a light blocking portion that blocks the light are alternately provided in the rotation direction of the rotating plate.
[0040]
In addition, the semiconductor manufacturing condition setting device 4 includes a spectroscope 28 that splits the fluorescence emitted from the chamber 6 through the monitoring window 24 and a PD (photodiode) array 30 that detects the fluorescence dispersed by the spectroscope 28. I have. The fluorescence is incident on the entrance slit of the spectroscope 28 and is decomposed into a spectrum by being irradiated on the diffraction grating. Although not shown, an optical fiber or the like is disposed between the monitoring window 24 and the spectroscope 28 in order to efficiently cause the fluorescence that has passed through the monitoring window 24 to enter the spectroscope 28. A plurality of photodiodes are arranged in the PD array 30 in the fluorescence spectral direction, in other words, in the spectral decomposition direction. The PD array 30 receives each wavelength component of fluorescence and photoelectrically converts the fluorescence to emit fluorescence. An analog signal corresponding to the intensity at each wavelength is output. Note that a filter can be used instead of the diffraction grating as the spectroscope, and a photomultiplier tube or the like can be used as the photodetector instead of the PD array 30.
[0041]
Further, between the spectroscope 28 and the PD array 30, a gate 29 that constitutes a light detection means together with the PD array 30 is interposed. The gate 29 switches between passage and blocking of light based on the light reception timing signal output from the timing signal generator 11.
[0042]
An A / D converter 32 that converts an analog signal output from the PD array 30 into a digital signal is connected to the PD array 30, and a controller 34 is connected to the A / D converter 32. ing. The control unit 34 has a built-in CPU 35 for performing various arithmetic processes. Further, the CPU 35 has data relating to fluorescence intensity at each wavelength of fluorescence output as a digital signal from the A / D converter 32 described above. And a ROM 35b in which a program for creating reference fluorescence data to be described later is stored. The CPU 35 is connected to a keyboard 38 so that a display 36 provided outside the control unit 34 can be output and a keyboard 38 can be input.
[0043]
Here, with reference to FIG. 4, two light reception timing signals generated by the timing signal generation unit 11 and a fluorescence intensity calculation method by the CPU 35 based on these signals will be described. The horizontal axis in FIG. 4 indicates the passage of time, and the vertical axis indicates the intensity of light emitted from the monitoring window 24 of the chamber 6 (unit is arbitrary). In addition, pulses indicated by diagonal lines indicate a state in which pulse excitation light is output from the pulse laser light source 5. As shown in this figure, there is a time lag between the irradiation of the excitation light to the particles in the plasma and the generation of fluorescence from the particles. This timing lag is stored in advance in the timing signal generator 11 as the light reception stop time.
[0044]
The timing signal generation unit 11 transmits a pulse timing signal to the pulse laser light source 5 and synchronizes with the pulse timing signal at a predetermined time T._SAnd T_E(T_S<T_E) Is generated. This signal is generated every time pulse excitation light is output. Time T_SIs the time after a predetermined light reception stop time has elapsed since the pulse light was output from the laser light source 5, and the time T_EIs the time when the generated fluorescence disappears. Such time T_SAnd T_EWhen the first light receiving timing signal instructing a predetermined time is input to the gate 29, the gate 29 is opened for a predetermined time indicated by the timing signal, and light can pass through. The split light reaches the PD array 30. At this time, since the gate 29 is opened when a large amount of fluorescence is generated from the plasma according to the first light reception timing signal, the PD array 30 efficiently receives the fluorescence emitted from the particles in the plasma 13. be able to. However, in this case, not only the fluorescence that is the detection target but also the plasma light that is noise is incident on the PD array 30, and a method for dealing with this problem will be described later. The time when the pulsed light is output and the time T_SThe light reception stop time between and can be set as appropriate. Specifically, it is desirable that the light reception stop time be about 0 to 50 ns. In addition, time T_EWith respect to, it can be set as appropriate before the next pulse is output.
[0045]
Next, the second light reception timing signal generated by the timing signal generator 11 will be described. The second light receiving timing signal is a predetermined time T in FIG._AAnd T_B(T_A<T_B). Where time T_AIs an arbitrary time in a state where excitation light is not output from the laser light source 5, that is, in a state where no fluorescence is generated from the plasma, and time T_BIs any time T_ATo a predetermined time T determined each time each pulse excitation light is output._1S~ T_1E, T_2S~ T_2E, T_3S~ T_3E, T_4S~ T_4EIt is the time when the total time of. Such time T_AAnd T_BWhen a second light receiving timing signal indicating a predetermined time between the two is input to the gate 29, the gate 29 is connected to the predetermined time (T_A~ T_B), The light passing state, and the light dispersed by the spectroscope 28 reaches the PD array 30. At this time, since the gate 29 is opened according to the second light reception timing signal when no fluorescence is generated, the PD array 30 receives only the plasma light which is noise.
[0046]
As described above, the PD array 30 that has become capable of receiving light by receiving the first light receiving timing signal and the second light receiving timing signal corresponds to the intensity of light received when the first light receiving timing signal is received. An electric signal and an electric signal corresponding to the intensity of light received when the second light receiving timing signal is received are transmitted to the CPU 35 via the A / D converter 32, respectively. And CPU35 which received these two electric signals calculates the intensity | strength of fluorescence by calculating | requiring the difference of these electric signals. That is, only the fluorescence intensity is obtained by subtracting the emission intensity of the plasma light from the value of the intensity of the fluorescence that is the detection target and the emission intensity of the plasma light that is noise.
[0047]
Next, a process of setting parameters as manufacturing conditions of the semiconductor manufacturing apparatus 2 by the semiconductor manufacturing condition setting apparatus 4 configured as described above will be described with reference to the flowcharts of FIGS. 1 and 5. The semiconductor manufacturing apparatus 2 includes (1) a high frequency power applied to the upper electrode 12a to generate the plasma 13, (2) a frequency for generating the plasma 13, and (3) a lower electrode 12b by a bias power source. (4) the flow rate of the gas flowing into the chamber 6, (5) the pressure in the chamber 6, (6) the strength of the magnetic field generated in the chamber by the magnet coil 20, (7) There are seven manufacturing parameters: temperature in the chamber 6.
[0048]
First, the process from the generation of plasma in the chamber 6 to the CPU 35 calculating the fluorescence intensity will be described with reference to FIG. Note that the etching process described first is not performed for formal processing of the wafer, but is performed for obtaining various data such as reference fluorescence data described later. Hereinafter, such etching performed for obtaining various data is referred to as test etching.
[0049]
While the gas introduction valve 8a is opened to allow the etching gas to flow into the chamber 6, the inside of the chamber 6 is depressurized to a predetermined pressure by operating the exhaust valve 10a, and the temperature in the chamber 6, more specifically, the wafer 7 is supported. After the temperature below the lower electrode 12b is set to a predetermined temperature, the high frequency generator 14 and the bias power source 16 are operated to apply high frequency power between the upper electrode 12a and the lower electrode 12b, whereby the electrodes 12a, 12b. In the meantime, plasma 13 is generated. The plasma 13 is maintained in a high density state by the magnetic field formed by the magnet coil 20.
[0050]
When plasma is generated, for example, CF_FourIs excited to become ions or radicals. These ions and the like are induced toward the wafer 7 placed on the lower electrode 12b by the action of the bias voltage, and are formed on the surface of the wafer 7 by SiO.₂React with the film and test etching proceeds.
[0051]
At the same time as the plasma is generated and the test etching proceeds, the timing signal generator 11 outputs a pulse timing signal, and the pulse laser light source 5 outputs pulse excitation light. At this time, the wavelength of the pulse excitation light is set to any of particles contained in the gas in the chamber 6 (for example, CF, CF, etc.) by adjusting the angle of the BBO crystal or operating the harmonic generator.₂, O, etc.) are adjusted to wavelengths that can excite. When pulse excitation light hits the particles in the plasma, fluorescence is generated from the particles. Note that the wavelength of the generated fluorescence differs depending on to which energy state the excited particles relax. The fluorescence generated from the particles passes through the monitoring window 24 and reaches the spectroscope 28. At this time, since the monitoring window 24 is fogged by the heater 26, the fluorescence can easily pass through the monitoring window 24.
[0052]
The fluorescence that has entered the entrance slit of the spectroscope 28 is decomposed into a spectrum by irradiating the diffraction grating. When the gate 29 is opened as described above, the fluorescence dispersed into the spectrum is received by the PD array 30, and fluorescence intensity data, which is data relating to the intensity at each wavelength of fluorescence, is output as an analog signal. . When the fluorescence intensity data reaches the A / D converter 32 as an analog signal, the analog signal is converted into a digital signal. The digitally converted fluorescence intensity data is transmitted to the CPU 35 of the controller 34. The CPU 35 calculates the fluorescence intensity of each wavelength of fluorescence based on the fluorescence intensity data, and stores the fluorescence intensity data in the RAM 35a. . The above is the process up to the calculation of the fluorescence intensity.
[0053]
Next, a control procedure in which the CPU 35 having calculated the fluorescence intensity sets and maintains each parameter during etching within a desired range will be described with reference to the flowchart of FIG. Although the desired range, which is the ideal range of parameters, cannot be determined by various instruments outside the chamber, it is possible to set and maintain the parameters within the ideal range based on information obtained from the fluorescence wavelength. This is the purpose of this embodiment.
[0054]
First, the operator forcibly changes the value of each parameter while performing test etching. For example, in order to increase or decrease the pressure in the chamber 6, the exhaust valve 10a may be adjusted. However, the parameters are changed one by one, and other parameters are not changed while a certain parameter is being changed. When the parameter value is forcibly changed, there are several wavelengths at which the fluorescence intensity changes with this change. The CPU 35 selects at least two or more wavelengths as corresponding wavelengths from among the wavelengths whose fluorescence intensities have changed (S101). That is, the corresponding wavelength means a wavelength that has a correlation with a parameter and changes the fluorescence intensity as the parameter value changes.
[0055]
Here, with reference to FIG. 6 once, the selection method of a corresponding wavelength is demonstrated concretely. FIG. 6A illustrates fluorescence intensity data indicating fluorescence intensities during etching at five wavelengths. The horizontal axis is the fluorescence wavelength, and the vertical axis is the fluorescence intensity (unit is arbitrary). FIG. 6B shows fluorescence intensity data when the gas flow rate is forcibly increased from a desired value, and large decreases and increases in fluorescence intensity are observed at wavelengths X and Y, respectively. Then, the CPU 35 selects a wavelength at which a large change in the fluorescence intensity is seen as the corresponding wavelength. The wavelength of the selected corresponding wavelength is stored in the RAM 35a. Note that three or more corresponding wavelengths may be selected. For example, in FIG. 6B, the wavelength adjacent to the left side of the wavelength X slightly increases in fluorescence intensity, so this wavelength is also selected as the corresponding wavelength. May be. References such as the number of wavelengths to be selected may be stored in advance in the RAM 35a or ROM 35b of the control unit 34, or may be input by the operator using the keyboard 38 each time.
[0056]
Again, the control procedure of the CPU 35 will be described with reference to the flowchart of FIG. After selecting the corresponding wavelength for each parameter, the CPU 35, based on the program stored in the ROM 35b, the reference fluorescence that is the relationship between the parameter value when the value is forcibly changed and the fluorescence intensity of each corresponding wavelength. Data is created (S102). FIG. 7 is a graph of the reference fluorescence data, and FIGS. 7A to 7C show the reference fluorescence data when the parameters are high frequency power, gas flow rate, and pressure, respectively. The vertical axis represents the fluorescence intensity (unit is arbitrary) of the corresponding wavelength, and the horizontal axis represents the parameter value. However, the value of this parameter is a value measured by a meter outside the chamber 6, and does not indicate an accurate value of the parameter in the chamber 6. The CPU 35 stores the created reference fluorescence data in the RAM 35a.
[0057]
As shown in FIGS. 7A to 7C, the high frequency power, the gas flow rate, and the pressure are all correlated with the three wavelengths A, B, and C. FIG. 8 is a table summarizing the relationship between parameters and corresponding wavelengths based on the reference fluorescence data of FIGS. 7A to 7C. When each parameter value is increased or decreased, each correspondence is shown. It shows whether the fluorescence intensity of the wavelength increases, decreases or remains unchanged. In this figure, an upward arrow indicates an increase, a downward arrow indicates a decrease, and a horizontal arrow indicates no change. From FIG. 8, for example, when the high-frequency power is increased, the fluorescence intensities at wavelengths A, B, and C all increase, and when the pressure is increased, the fluorescence intensity at wavelength A is increased and the fluorescence intensity at wavelength B is increased. Is unchanged, and the fluorescence intensity at wavelength C decreases.
[0058]
Again, the control procedure of the CPU 35 will be described with reference to the flowchart of FIG. After creating the reference fluorescence data, the CPU 35 determines an allowable fluorescence range that is a range of fluorescence intensity of each corresponding wavelength corresponding to the allowable range of the parameter based on the reference fluorescence data (S103). Note that the acceptable range of parameters is found by repeating the test etch. If the high-frequency power fluctuates normally during etching, a product defect caused by the high-frequency power does not naturally occur. However, if the high-frequency power is forcibly increased to a certain value or more at a certain time after the start of etching, the resist film applied on the wafer undergoes thermal alteration due to heating from the plasma. If the resist film changes in quality, the etching is not performed as designed, leading to product defects. That is, the power value at this time is an upper limit that does not cause a problem in the product. On the other hand, when the high-frequency power is reduced to a certain value, the etching rate is lowered due to insufficient plasma density and insufficient wafer temperature, and the etching process takes a long time. That is, the power value at this time is a lower limit that does not cause a problem in the product. Then, considering a sufficient margin from these upper and lower limits is an allowable range of high-frequency power when other parameters are under a certain condition, and the fluorescence intensity at this time is an allowable fluorescence range. When the operator inputs the upper limit value and the lower limit value of the allowable fluorescence range, the CPU 35 determines the range defined by these values as the allowable fluorescence range. After determining the allowable fluorescence range, the CPU 35 stores data related to the allowable fluorescence range in the RAM 35a.
[0059]
If it is desired to improve the etching accuracy, the allowable fluorescence range may be narrowed and input. In addition to high-frequency power, even if the gas flow rate or pressure is forcibly changed, the characteristics of the wafer after the etching process such as defective etching shape, reduced etching rate, and in-plane non-uniformity can be considered. The allowable fluorescence range is determined by grasping in advance when adverse effects occur. Further, for a parameter whose value changes every moment from the start of etching, such as the temperature in the chamber 6, the allowable fluorescence range is determined every arbitrary time from the start of etching. Furthermore, the CPU 35 can be configured to determine the allowable fluorescence range without the operator determining the allowable fluorescence range. For example, after completing the test etching, an operator who confirms that the completed wafer 7 is of high quality and the etching process was performed under ideal parameter values, the fluorescence intensity of each corresponding wavelength at that time Enter. Then, the CPU 35 provides a predetermined tolerance for the input fluorescence intensity, and determines the range of this tolerance as the tolerance fluorescence range. Note that the width of the allowable fluorescence range can be adjusted by changing the allowable error range.
[0060]
The test etching is completed up to the above step 103, and then the etching process for the wafer 7 is actually started, and the semiconductor manufacturing condition setting device 4 sets and maintains the values of the respective parameters within the allowable range during the etching. . Hereinafter, this process will be described.
[0061]
The fluorescence generated during the etching is spectrally divided by the spectroscope 28, and the fluorescence intensity data of each wavelength component reaches the CPU 35 via the PD array 30 and the A / D converter 32. Here, the CPU 35 calls the reference fluorescence data of each parameter and data related to the wavelength of the corresponding wavelength from the RAM 35a. Thereafter, the CPU 35 monitors only the fluorescence intensity of the corresponding wavelength in the fluorescence intensity data, and calculates the fluorescence intensity of each corresponding wavelength during the etching process as the in-process fluorescence intensity as needed (S104).
[0062]
After calculating the fluorescence intensity during processing, the CPU 35 selects candidate parameters corresponding to the fluorescence intensity during processing from the parameters based on the reference fluorescence data (S105). A candidate parameter means a parameter that has influenced the change in fluorescence intensity during processing. Here, the candidate parameter selection method will be described with reference to FIG. 8 that summarizes the reference fluorescence data. For example, when the fluorescence intensities of wavelengths A, B, and C all increase during etching, it is estimated from the correlation shown in the upper part of FIG. 8 that the high frequency power has increased for some reason, and the high frequency power is a candidate parameter. Selected as When the fluorescence intensities at wavelengths A and B increase and the fluorescence intensity at wavelength C decreases, it is estimated from the correlation in the middle of FIG. 8 that the gas flow rate in the chamber 6 has decreased for some reason. The gas flow rate is selected as a candidate parameter. Further, when the fluorescence intensity at wavelength B does not change, the fluorescence intensity at wavelength A increases, and the fluorescence intensity at wavelength C decreases, the pressure in the chamber 6 is caused by some reason from the correlation in the lower part of FIG. And pressure is selected as a candidate parameter.
[0063]
In the data shown in FIG. 8, since the combination of changes in the corresponding wavelengths is different for each parameter, one parameter can be determined by obtaining the increase / decrease changes in the three corresponding wavelengths. However, when two parameters are increased or decreased, all three corresponding wavelengths may change the same. In such a case, the CPU 35 selects the candidate parameter by increasing the number of corresponding wavelengths to be selected or comparing the value of the emission intensity during processing itself with the value of the reference fluorescence data.
[0064]
Again, the control procedure of the CPU 35 will be described with reference to the flowchart of FIG. After selecting the candidate parameter, the CPU 35 displays the reference fluorescence data corresponding to the candidate parameter on the display 36 (S106). At this time, the display 36 also shows (1) the time after the start of etching, (2) the allowable fluorescence range of the candidate parameter at the time after the start of etching called from the RAM 35a, and (3) the fluorescence intensity during the current process. Also displayed. When the candidate parameter exceeds the allowable range and becomes an abnormal value during the etching, the in-process fluorescence intensity displayed on the display 36 changes to exceed the allowable fluorescent range. At this time, the operator obtains the difference between the limit value of the allowable fluorescence range and the in-process fluorescence intensity, and refers to the reference fluorescence data to determine how much the candidate parameter value should be adjusted to fill this difference. And ask. The operator who has obtained the adjustment amount of the candidate parameter operates various instruments such as a high-frequency generator in order to return the value of the candidate parameter to the normal range. Then, by operating various instruments until the fluorescence intensity during the process falls within the allowable fluorescence range, the candidate parameters in the chamber 6 can be set and maintained in the vicinity of the desired range, thereby making the etching process stable. You can proceed in the state. Note that the CPU 35 may be configured to notify the operator by an alarm when the fluorescence intensity during processing exceeds the allowable fluorescence range. Further, the CPU 35 may determine the difference between the limit value of the allowable fluorescence range and the in-process fluorescence intensity instead of the operator.
[0065]
After displaying the reference fluorescence data on the display 36, the CPU 35 determines whether or not the etching reaches the end point (S107). The CPU 35 refers to the data stored in the ROM 35b and the arithmetic expression input by the operator when determining whether or not the etching has reached the end point. If the end point has not been reached, the process returns to step 104 to calculate the in-process fluorescence intensity again. On the other hand, if it is an end point, the process proceeds to step 108, and the operator is notified by displaying on the display 36 that the etching has been completed. Of course, it is also possible to send the etching end command to the chamber 6.
[0066]
(Second Embodiment)
FIG. 9 shows the overall configuration of the semiconductor manufacturing apparatus 2 according to the second embodiment. This embodiment is different from the first embodiment in that the semiconductor manufacturing condition setting apparatus 4 controls each parameter value. It is a point equipped with parts 40-50. The high frequency control unit 40 transmits a control signal to the high frequency generator 14 to control high frequency power and frequency. The magnetic field control unit 42 transmits a control signal to the magnet coil 20 to strengthen the magnetic field in the chamber 6. Is to control. The temperature control unit 44 transmits a control signal to the temperature regulator 18 to control the temperature in the chamber 6. The bias voltage control unit 46 transmits a control signal to the bias power source 16 to set the bias voltage. It is something to control. Further, the pressure control unit 48 transmits a control signal to the exhaust valve 10a to control the pressure in the chamber 6, and the gas flow rate control unit 50 transmits a control signal to the gas introduction valve 8a to transmit the gas flow rate. Is to control. These control units 40 to 50 are all connected to the CPU 35 of the control unit 34.
[0067]
Next, a process of setting parameters as manufacturing conditions of the semiconductor manufacturing apparatus 2 by the semiconductor manufacturing condition setting apparatus 4 configured as described above will be described with reference to the flowchart of FIG. However, the process from the selection of the corresponding wavelength in Step 101 to the selection of the candidate parameter in Step 105 is the same as that in the first embodiment, and thus the description thereof is omitted.
[0068]
After selecting candidate parameters in step 105, the CPU 35 determines whether or not the in-process fluorescence intensity exceeds the allowable fluorescence range of each parameter (S106). If the fluorescence intensity during processing does not exceed the allowable fluorescence range, it means that the etching is performed normally, and the routine proceeds to step 109 to determine whether or not the etching has reached the end point. When the end point has not been reached, the process returns to step 104, and the in-process fluorescence intensity is calculated again. On the other hand, if it is an end point, the process proceeds to step 110 to display on the display 36 that the etching is completed and notify the operator, and the CPU 35 transmits a stop signal to each of the control units 40 to 50 to control each control. The units 40 to 50 transmit an end signal to the high-frequency generator 14, the magnet coil 20, the temperature regulator 18, the bias power source 16, the exhaust valve 10a, and the gas introduction valve 8a, respectively, to perform the etching end operation.
[0069]
On the other hand, when the in-process fluorescence intensity exceeds the allowable fluorescence range in step 106, the CPU 35 transmits a control signal to each of the control units 40-50. For example, assume that temperature is selected as a candidate parameter. In this case, when the fluorescence intensity during processing for each corresponding wavelength exceeds the allowable fluorescence range related to temperature, the CPU 35 (parameter value setting means) transmits a command to control the temperature to the temperature control unit 44, and The temperature control unit 44 (parameter value control means) that has received the command adjusts the temperature regulator 18.
[0070]
After transmitting the command to the temperature control unit 44, the CPU 35 determines whether or not the in-process fluorescence intensity of each corresponding wavelength is within the allowable fluorescence range (S108). If the fluorescence intensity during processing for each corresponding wavelength does not fall within the allowable fluorescence range, the CPU 35 returns to step 107 and transmits a command to control the temperature to the temperature control unit 44 again. On the other hand, if the fluorescence intensity during processing for each corresponding wavelength falls within the allowable fluorescence range, the temperature is at an ideal value at that time, and the process proceeds to step 109, where etching has reached the end point. Determine whether or not. In the present embodiment, the case where the temperature is controlled has been described. However, other parameters can be similarly controlled.
[0071]
If the etching has reached the end point, the process proceeds to step 111, where the display 36 is displayed on the display 36 to notify the operator, and the CPU 35 sends a stop signal to each of the control units 40-50, The control units 40 to 50 transmit an end signal to the high-frequency generator 14, the magnet coil 20, the temperature regulator 18, the bias power source 16, the exhaust valve 10a, and the gas introduction valve 8a, respectively, to perform the etching end operation. According to the semiconductor manufacturing apparatus 2 of the present embodiment, the CPU 35 can bring the parameters closer to the desired range by setting the fluorescence intensity during processing of each corresponding wavelength within the allowable range, so that there is no need for the operator to operate. For this reason, a high-quality semiconductor substrate can be obtained while the etching process proceeds smoothly. In addition, defective products can be reduced and yield can be improved. Moreover, since the opportunity for the semiconductor manufacturing apparatus to deviate from the stable state is reduced, the operation time of the apparatus is extended, and the productivity as a whole is improved.
[0072]
(Third embodiment)
The configuration of the semiconductor manufacturing condition setting apparatus of the third embodiment is the same as the configuration of the second embodiment. The difference from the semiconductor manufacturing condition setting device 4 of the second embodiment is that the ratio of the fluorescence intensity of each corresponding wavelength is used instead of using the fluorescence intensity itself in order to set and maintain each parameter within the ideal range. There is a feature in the point. Specifically, the reference fluorescence data indicates the relationship between the value of the parameter and the ratio of the fluorescence intensity of each wavelength (value based on the fluorescence intensity), and the allowable fluorescence range is the ratio of the fluorescence intensity of each corresponding wavelength. (Range based on fluorescence intensity). Then, when the value of the ratio of the in-process fluorescence intensity calculated for each corresponding wavelength (value based on the in-process fluorescence intensity) exceeds the allowable fluorescence range, the value of the candidate parameter is adjusted.
[0073]
According to the semiconductor manufacturing condition setting device of the present embodiment, since various calculation processes are performed using the ratio of the fluorescence intensity between the corresponding wavelengths, not the value of the fluorescence intensity of each corresponding wavelength, For example, even if the ambient temperature outside the chamber changes and the sensitivity of the PD array decreases, the relative value of the fluorescence intensity of each corresponding wavelength hardly changes, so that errors are less likely to occur when compared with the reference fluorescence data. The candidate parameters can be efficiently maintained in the vicinity of the desired range.
[0074]
As mentioned above, although the invention made | formed by this inventor was concretely demonstrated based on embodiment, this invention is not limited to the said embodiment. For example, the processing on the wafer is not limited to etching, and may be another plasma process such as sputtering or plasma CVD.
[0075]
【The invention's effect】
As described above, according to the present invention, by monitoring the change in the fluorescence intensity, it is possible to grasp the change in the parameter that cannot be measured by an external instrument, to perform the semiconductor plasma process in a stable state, and High quality semiconductors can be manufactured.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a semiconductor manufacturing apparatus according to a first embodiment.
FIG. 2 (a) is a diagram showing a structure using mesh electrodes in order to prevent fogging of a monitoring window. FIG. 2A is a diagram showing a structure using an annular electrode to prevent the monitoring window from fogging.
3 is a sectional view of the chamber shown in FIG. 1 in the III-III direction.
FIG. 4 is a diagram used for explaining a light reception timing signal generation method by a timing signal generation unit;
FIG. 5 is a flowchart showing a control procedure of the CPU according to the first embodiment.
FIG. 6 is fluorescence intensity data used for explaining a method of selecting a corresponding wavelength in the first embodiment, and FIG. 6A is a diagram showing fluorescence intensity before changing a parameter value. FIG. 6B is a diagram showing the fluorescence intensity when the parameter value is forcibly changed.
FIG. 7A is a diagram showing reference fluorescence data of high-frequency power. FIG. 7B is a diagram showing the reference fluorescence data of the gas flow rate. FIG. 7C is a diagram showing pressure reference fluorescence data.
FIG. 8 is a table summarizing the relationship between parameters and corresponding wavelengths based on the reference fluorescence data of FIGS.
FIG. 9 is an overall configuration diagram of a semiconductor manufacturing apparatus according to a second embodiment.
FIG. 10 is a flowchart showing a control procedure of a CPU according to a second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 2 ... Semiconductor manufacturing apparatus, 4 ... Semiconductor manufacturing condition setting apparatus, 5 ... Pulse laser light source, 6 ... Chamber, 7 ... Wafer, 8 ... Gas introduction port, 8a ... Gas introduction valve, 10 ... Exhaust port, 10a ... Exhaust valve, DESCRIPTION OF SYMBOLS 11 ... Timing signal generation part, 12a ... Upper electrode, 12b ... Lower electrode, 13 ... Plasma, 14 ... High frequency generator, 16 ... Bias power supply, 18 ... Temperature regulator, 20 ... Magnetic coil, 22 ... Projection part, 24 ... Monitoring window, 26 ... heater, 29 ... gate, 34 ... control unit.

Claims (10)

A method of setting manufacturing conditions of a semiconductor manufacturing process for processing a substrate to be processed using plasma generated in a chamber,
Irradiating the plasma with excitation light to generate fluorescence;
Spectroscopically analyzing the fluorescence;
Calculating the fluorescence intensity of each wavelength of the separated fluorescence;
Each parameter with at least two or more wavelengths as corresponding wavelengths from among the wavelengths at which the fluorescence intensity changes in accordance with the increase / decrease change of the parameter when the values of the plurality of parameters as the manufacturing conditions are changed Process to select for each,
Creating, for each parameter, reference fluorescence data indicating whether the fluorescence intensity of each corresponding wavelength is increased, decreased, or unchanged when the value of the parameter is increased or decreased;
Determining an allowable fluorescence range corresponding to the allowable range of the parameter based on the fluorescence intensity of each corresponding wavelength for each of the parameters;
Calculating a fluorescence intensity during processing that is a fluorescence intensity of each of the corresponding wavelengths of the fluorescence obtained when performing the treatment on the substrate to be treated;
Selecting a candidate parameter according to the in-process fluorescence intensity based on the reference fluorescence data from the parameters;
Adjusting the value of the candidate parameter until the value based on the fluorescence intensity during processing falls within the allowable fluorescence range when the value based on the fluorescence intensity during treatment exceeds the allowable fluorescence range;
A semiconductor manufacturing condition setting method comprising:   The parameters include a high frequency power for generating the plasma, a frequency for generating the plasma, a bias voltage for inducing ions or radicals contained in the plasma toward the substrate to be processed, and in the chamber 2. The flow rate of the inflowing gas, the pressure in the chamber, the strength of a magnetic field for maintaining the plasma at a high density, or the temperature in the chamber is at least one of the above. Semiconductor manufacturing condition setting method. An apparatus for setting manufacturing conditions of a semiconductor manufacturing process for processing a substrate to be processed using plasma generated in a chamber,
Excitation light generating means for outputting excitation light;
A spectroscopic means for spectroscopically analyzing fluorescence emitted from the particles in the plasma by irradiation of the excitation light;
Photodetection means having resolution in the spectral direction of the fluorescence, receiving each wavelength component of the dispersed fluorescence and outputting an electrical signal according to the intensity of each wavelength of the fluorescence;
Fluorescence intensity calculation means for calculating the fluorescence intensity of each wavelength of the fluorescence based on the electrical signal output from the light detection means;
Each parameter with at least two or more wavelengths as corresponding wavelengths from among the wavelengths at which the fluorescence intensity changes in accordance with the increase / decrease change of the parameter when the values of the plurality of parameters as the manufacturing conditions are changed Corresponding wavelength selection means to select for each,
Reference fluorescence data for creating, for each parameter, reference fluorescence data indicating whether the fluorescence intensity of each corresponding wavelength is increased, decreased, or unchanged when the value of the parameter is increased or decreased. Creating means;
An allowable fluorescence range determining means for determining, for each of the parameters, an allowable fluorescence range that is a range based on the fluorescence intensity of each corresponding wavelength corresponding to the allowable range of the parameter;
An in-process fluorescence intensity calculating means for calculating an in-process fluorescence intensity that is a fluorescence intensity of each of the corresponding wavelengths of the fluorescence obtained when performing the process on the substrate to be processed;
Based on the reference fluorescence data, candidate parameter selection means for selecting candidate parameters according to the in-process fluorescence intensity from the parameters;
The rewritable transmits a pulse timing signal for the excitation light to the pulsed pump light to the excitation light generating means, in synchronization with the pulse timing signals, a predetermined light receiving stop time elapses after one pulse excitation light is outputted Timing signal generating means for generating a first light reception timing signal indicating a predetermined time from the time to the time before the next pulse excitation light is output;
With
2. The semiconductor manufacturing condition setting apparatus according to claim 1, wherein the light detection means is in a light receiving state for the predetermined time based on the first light reception timing signal . Parameter value control means for controlling the value of the candidate parameter by receiving a control signal;
Parameter value for transmitting the control signal to the parameter value control means until the value based on the in-process fluorescence intensity falls within the allowable fluorescence range when the value based on the in-process fluorescence intensity exceeds the allowable fluorescence range Setting means;
The semiconductor manufacturing condition setting device according to claim 3, further comprising:   The parameters include a high frequency power for generating the plasma, a frequency for generating the plasma, a bias voltage for inducing ions or radicals contained in the plasma toward the substrate to be processed, and in the chamber 4. The flow rate of the inflowing gas, the pressure in the chamber, the strength of a magnetic field for maintaining the plasma at a high density, or the temperature in the chamber. Semiconductor manufacturing condition setting device. The timing signal generation means further generates a second light reception timing signal that indicates the same time as the predetermined time when the excitation light generation means is in an output stop state of the excitation light,
The photodetection means is in a first light reception enabled state for the predetermined time based on the first light reception timing signal, and secondly for the same time as the predetermined time based on the second light reception timing signal. It becomes ready to receive light,
The fluorescence intensity calculation means is based on a difference between an electrical signal output from the light detection means in the first light-receiving ready state and an electrical signal output from the light detection means in the second light-receiving ready state. 4. The semiconductor manufacturing condition setting device according to claim 3 , wherein the fluorescence intensity is calculated. In a semiconductor manufacturing apparatus for manufacturing a semiconductor substrate by generating plasma in a chamber and processing the substrate to be processed using the plasma,
A semiconductor manufacturing condition setting device according to any one of claims 3 to 6 ,
The chamber has an incident window for allowing the excitation light to enter the chamber, and a monitoring window for emitting the emission of the plasma and the fluorescence in the chamber to the outside.
The said manufacturing means of the said semiconductor manufacturing condition setting apparatus is arrange | positioned in the position where the said plasma light and the said fluorescence which passed the said monitoring window inject. The semiconductor manufacturing apparatus according to claim 7 , wherein at least one of the incident window and the monitoring window includes a defogging unit. 9. The semiconductor manufacturing apparatus according to claim 8 , wherein the anti-fogging means is a heater for heating the monitoring window. A method of setting conditions for a process for processing a substrate to be processed using plasma,
Irradiating the plasma with excitation light to generate fluorescence;
Spectroscopically analyzing the fluorescence;
Calculating the fluorescence intensity of each wavelength of the separated fluorescence;
For each of the parameters, at least two or more wavelengths are used as the corresponding wavelengths from among the wavelengths at which the fluorescence intensity changes in accordance with the increase / decrease in the parameter when the values of the plurality of parameters as the conditions are increased / decreased. A process to select
Creating, for each parameter, reference fluorescence data indicating whether the fluorescence intensity of each corresponding wavelength is increased, decreased, or unchanged when the value of the parameter is increased or decreased;
Determining an allowable fluorescence range corresponding to the allowable range of the parameter based on the fluorescence intensity of each corresponding wavelength for each of the parameters;
Calculating a fluorescence intensity during processing that is a fluorescence intensity of each of the corresponding wavelengths of the fluorescence obtained when performing the treatment on the substrate to be treated;
Selecting a candidate parameter according to the in-process fluorescence intensity based on the reference fluorescence data from the parameters;
Adjusting the value of the candidate parameter until the value based on the fluorescence intensity during processing falls within the allowable fluorescence range when the value based on the fluorescence intensity during treatment exceeds the allowable fluorescence range;
A condition setting method in plasma processing, comprising:

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