JP3984868B2 - Plasma etching apparatus simulation apparatus and plasma etching apparatus including the simulation apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a simulation apparatus for a semiconductor manufacturing apparatus, and relates to a semiconductor manufacturing apparatus including the simulation device, in particular, plasma etching can confirm a series of operations of the plasma etching apparatus without actually operating the plasma etching apparatus The present invention relates to an apparatus simulation apparatus and a plasma etching apparatus including the simulation apparatus.
[0002]
[Prior art]
In a semiconductor manufacturing process, for example, a plasma processing apparatus is used in an etching process of an object to be processed such as a semiconductor wafer.
[0003]
A conventional plasma processing apparatus includes a processing chamber in which the inside is maintained at a high vacuum so as to perform etching processing of a semiconductor wafer, a lower electrode that is disposed in a lower portion of the processing chamber and serves also as a mounting table on which the semiconductor wafer is mounted, And an upper electrode which is disposed above the lower electrode in the processing chamber and also serves as a shower head for supplying process gas into the processing chamber.
[0004]
The plasma processing apparatus includes a high-frequency power source that supplies high-frequency power to the upper electrode and the lower electrode, an electric measuring device that detects a fundamental frequency and harmonic voltage, current, etc. of these high-frequency power, and a flow rate that controls the flow rate of the process gas. It has a control device, a gas flow rate sensor for measuring the flow rate of the process gas, a temperature sensor for detecting the temperature in the processing chamber, a pressure sensor for detecting the pressure in the processing chamber, and a plasma emission spectrometer.
[0005]
On the other hand, a control device is connected to each of the high-frequency power source, the flow rate control device, the electrical measuring instrument, the gas flow rate sensor, the temperature sensor, the pressure sensor, and the plasma emission spectrometer. An input / output device is connected to the control device.
[0006]
The control device sets the device parameters for the etching process of the high-frequency power source and the flow rate control device via the input / output device, and via the electrical measuring device, gas flow rate sensor, temperature sensor, plasma emission spectrometer, and pressure sensor. The state of the etching process is detected, and these detected values are output to the input / output device. This control apparatus controls the plasma processing apparatus to perform a desired etching process based on the detection value detected as described above.
[0007]
The electrical meter, gas flow sensor, temperature sensor, and pressure sensor serve as parameter sensors, and the plasma emission spectrometer serves as an additional sensor. The electrical measuring instrument also serves as an additional sensor for detecting the fundamental frequency and harmonic voltage, current, etc. of the high frequency power supply.
[0008]
Further, the control device stores detection data from the parameter sensor and the additional sensor, and sets a permissible variation range of the detection value from the parameter sensor and the additional sensor based on the stored detection data. This variation tolerance range is that a trial device is manufactured using a semiconductor wafer of the same material and structure as the actual process before “actual processing” in which a semiconductor device is actually subjected to plasma processing to manufacture a device as a product. Measure the specifications of the trial semiconductor wafer before etching and the specifications of the manufactured trial device, respectively, and the maximum value of the detection data of the parameter sensor and the additional sensor when the trial device satisfying the desired device specifications (expected specifications) is manufactured, and Set by minimum value.
[0009]
Such a control device determines that a device that satisfies the expected specifications is manufactured by normal etching when the detected data from the parameter sensor and the additional sensor obtained during actual device manufacturing processing are within the allowable range of variation. If any one of the detection data is not within the fluctuation allowable range, it is determined that a device that does not satisfy the expected specification is manufactured by abnormal etching.
[0010]
[Problems to be solved by the invention]
However, the controller of the plasma processing apparatus can only determine whether or not a device that satisfies the expected specifications has been manufactured by normal etching during actual processing of the device manufacturing, and the plasma processing apparatus can fail. When the actual device manufacturing process cannot be performed due to the above, the normal operation of the control device cannot be confirmed.
[0011]
An object of the present invention is to provide a plasma etching apparatus simulation apparatus capable of confirming a series of normal operations of the plasma etching apparatus without actually operating the plasma etching apparatus, and a plasma etching apparatus provided with the simulation apparatus. It is in.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, a simulation apparatus according to claim 1 is connected to a plasma etching apparatus for processing a semiconductor wafer and performs an operation simulation of the plasma etching apparatus. Includes a CPU, a plurality of sensors controlled by the CPU, a sensor data storage unit, and a sensor data simulator, and the plurality of sensors have a plurality of processing parameters when the semiconductor wafer is actually processed by the plasma etching apparatus. The sensor data storage unit stores the plurality of measured processing parameters in association with each other in time series of actual processing events of the plasma etching apparatus, and the sensor data simulator stores the associated processing parameters. The plasma etching apparatus is simulated to operate based on parameters, and the processing parameters include a temperature of a processing chamber, a pressure of the processing chamber, a characteristic value of a high-frequency power source applied to the processing chamber, and the processing chamber and the supply amount of the etching gas supplied to a supply amount of the carrier gas supplied into the processing chamber, looking containing a end point of the etching process, the characteristic values of the high frequency power source, a high frequency voltage, the high-frequency and current, and the high-frequency phase, and the high frequency impedance and wherein the free Mukoto.
[0013]
According to the simulation apparatus according to claim 1, the sensor data storage unit, a plurality of process parameters measured by the plurality of sensors and stores the association in the time series of the actual processing of the event of the plasma etching apparatus, the sensor data simulator, because simulated actuates the plasma etching apparatus based on the associated process parameters, it is possible to confirm the sequence of operation of the plasma etching apparatus without actually operating the plasma etching apparatus.
[0016]
The plasma etching apparatus according to claim 2 is a plasma etching apparatus that processes a semiconductor wafer and includes a simulation apparatus, wherein the simulation apparatus includes a CPU, a plurality of sensors controlled by the CPU, a sensor data storage unit, and sensor data. A plurality of sensors, each of the plurality of sensors measures a plurality of processing parameters during actual processing of the semiconductor wafer by the plasma etching apparatus, and the sensor data storage unit stores the plurality of measured processing parameters The sensor data simulator simulates and operates the plasma etching apparatus based on the associated processing parameter, and stores the processing parameter in a process sequence. Room temperature, and Pressure of the lab, characteristic value of the high frequency power source applied to the processing chamber, supply amount of the etching gas supplied to the processing chamber, supply amount of the carrier gas supplied to the processing chamber, and etching process look including the end point of the characteristic value of the high frequency power supply is a high frequency voltage, and the high frequency current, and the high-frequency phase, characterized in including Mukoto and the high frequency impedance.
[0017]
According to the semiconductor manufacturing apparatus of the fourth aspect, the same effect as that of the first aspect can be obtained.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a simulation apparatus for a plasma etching apparatus according to an embodiment of the present invention and a plasma etching apparatus provided with the simulation apparatus will be described in detail with reference to the drawings.
[0019]
FIG. 1 is a diagram showing a schematic configuration of a plasma etching apparatus according to an embodiment of the present invention.
[0020]
In FIG. 1, a plasma processing apparatus (plasma etching apparatus) 11 is made of a conductive material such as aluminum, and a processing chamber 12 in which the inside is held at a high vacuum so as to perform an etching process on a semiconductor wafer W as an object to be processed. A lower electrode 13 which is disposed in the lower part of the processing chamber 12 and also serves as a mounting table on which the semiconductor wafer W is mounted; and a process gas which will be described later is disposed in the processing chamber 12 above the lower electrode 13. 2 is provided with an upper electrode 14 that also serves as a shower head to be supplied to the inside of the apparatus 12, and a control device 41 shown in FIG. A focus ring 13a for focusing plasma P generated in the processing chamber 12 (to be described later) on the semiconductor wafer W to improve the efficiency of plasma processing is disposed on the periphery of the top of the lower electrode 13, and the focus ring 13a An electrostatic chuck (not shown) that electrostatically attracts the semiconductor wafer W is provided inside. Further, the processing chamber 12 has a pressure sensor 12a for detecting the internal pressure.
[0021]
A gas pipe 22 and a gas pipe 23 are connected to the upper electrode 14 via a common gas pipe 21. An etching gas for an etching gas such as a CF-based gas is connected to the gas pipe 22 via a flow rate control device 26. A supply source 24 is connected, and a carrier gas supply source 25 for a carrier gas such as Ar gas is connected to the gas pipe 23 via a flow rate control device 28. The flow controller 26 controls the supply amount of the etching gas, and the flow controller 28 controls the supply amount of the carrier gas. The etching gas supplied from the etching gas supply source 24 and the carrier gas supplied from the carrier gas supply source 25 are mixed in the common gas pipe 21 and processed as a process gas via the upper electrode (shower head) 14. 12 is evenly distributed in the discharge. The gas pipe 22 is provided with a gas flow rate sensor 27 for detecting the flow rate of the etching gas, and the gas pipe 23 is provided with a gas flow rate sensor 29 for detecting the flow rate of the carrier gas.
[0022]
A high frequency power source 19 is connected to the upper electrode 14 via a matching unit 18, and the high frequency power source 19 applies a high frequency power of 60 MHz, for example, to the upper electrode 14. An electrical measuring instrument 20 is connected between the upper electrode 14 and the matching unit 18, and the electrical measuring instrument 20 has a fundamental frequency and harmonic voltage, current, phase, and impedance of the high frequency power supply 19 applied to the upper electrode 14. Detect electrical signals such as.
[0023]
A high frequency power supply 16 is connected to the lower electrode 13 via a matching unit 15, and the high frequency power supply 16 applies a high frequency power of 2 MHz, for example, to the lower electrode 13. An electrical measuring instrument 17 is connected between the lower electrode 13 and the matching unit 15, and the electrical measuring instrument 17 has a fundamental frequency and harmonic voltage, current, phase, and impedance of the high frequency power source 16 applied to the lower electrode 13. Detect electrical signals such as.
[0024]
The lower electrode 13 is provided with a temperature sensor 13b that detects the temperature of the lower electrode 13 and the temperature of the semiconductor wafer W during the etching process.
[0025]
The plasma processing apparatus 11 configured as described above causes plasma to be generated by RF discharge by applying high-frequency power of 60 MHz, for example, to the process gas supplied into the processing chamber 12 maintained in a high vacuum via the upper electrode 14. Reactive ion etching is performed on the semiconductor wafer W by generating a P and applying a bias potential, for example, with a high frequency power of 2 MHz through the lower electrode 13.
[0026]
A window 30 in which, for example, quartz glass is embedded is formed on the side wall of the processing chamber 12, and a plasma emission spectrometer 31 is disposed in the window 30. The plasma emission spectrometer 31 spectrally separates plasma with a specific wavelength and detects the end point of the etching process based on the change in the intensity of the plasma with the specific wavelength.
[0027]
The high-frequency power sources 16 and 19, the flow rate control devices 26 and 28, the electric measuring devices 17 and 20, the gas flow rate sensors 27 and 29, the temperature sensor 13b, the plasma emission spectroscope 31, and the pressure sensor 12a are respectively controlled in FIG. An apparatus (APC server) 41 is connected. An input / output device 51 is connected to the control device 41.
[0028]
The control device 41 sets device parameters for etching processing of the high-frequency power sources 16 and 19 and the flow rate control devices 26 and 28 via the input / output device 51 (setting means), as well as the electrical measuring instruments 17 and 20, and the gas flow rate sensor 27. 29, the temperature sensor 13b, the plasma emission spectrometer 31, and the pressure sensor 12a are used to detect the state of the etching process, and the detected values and the like are output to the input / output device 51. The control device 41 controls the plasma processing apparatus 11 so as to perform a desired etching process based on the detection value detected as described above.
[0029]
The apparatus parameters include control values of electrical signals (characteristic values) such as harmonic voltages, currents, phases, and impedances of the high-frequency power supplies 16 and 19, the supply amount of the etching gas controlled by the flow control device 26, and the flow control device. 28 includes the amount of carrier gas to be controlled.
[0030]
The electrical measuring instruments 17 and 20, the gas flow sensors 27 and 29, the temperature sensor 13b, and the pressure sensor 12a function as parameter sensors, and the plasma emission spectrometer 31 functions as an additional sensor. The electrical measuring instruments 17 and 20 also function as additional sensors for detecting electrical signals such as the fundamental frequency and harmonic voltage, current, phase, and impedance of the high-frequency power supplies 16 and 19.
[0031]
The plasma processing apparatus 11 has an apparatus data detection unit (not shown). The apparatus data detection unit detects apparatus data such as ID data and event data of the semiconductor wafer W that is being etched.
[0032]
FIG. 2 is a block diagram showing a schematic configuration of the simulation apparatus according to the embodiment of the present invention.
[0033]
In FIG. 2, a control device 41 as a simulation device includes electrical measurement devices 17 and 20 as parameter sensors, gas flow rate sensors 27 and 29, temperature sensor 13 b, detection data detected by the pressure sensor 12 a, and an additional sensor. The detection data detected by the plasma emission spectrometer 31 (hereinafter, these detection data are collectively referred to as “sensor data”) (processing parameters) are stored in the sensor data storage unit 42 and the sensor data storage unit 42. A processing unit 43 for controlling the plasma processing apparatus 11 based on the obtained sensor data to execute a predetermined etching process, a sensor data storage unit 44 (association unit), a sensor simulator 45 (operation unit), and an apparatus data storage unit 46 (association means), device simulator 47 (actuation means), sensor And a chromatography data storage unit 42, processing unit 43, the sensor data storage unit 44, the sensor simulator 45, for controlling the device data storage unit 46 and the device simulator 47, CPU 48. The sensor data storage unit 44, sensor simulator 45, device data storage unit 46, and device simulator 47 perform an operation simulation of the control device 41 described later.
[0034]
Sensor data includes a high frequency power supply 16 applied to the lower electrode 13 detected by the electrical measuring instrument 17 and a fundamental frequency and a harmonic voltage for the high frequency power supply 19 applied to the upper electrode 14 detected by the electrical measuring instrument 20, Each electrical signal such as current, phase, and impedance, the flow rate of the etching gas detected by the gas flow rate sensor 27, the flow rate of the carrier gas detected by the gas flow rate sensor 29, and the lower part during the etching process detected by the temperature sensor 13b It includes the temperature of the electrode 13 and the semiconductor wafer W, the internal pressure of the processing chamber 12 detected by the pressure sensor 12a, and the end point of the etching process detected by the plasma emission spectrometer 31.
[0035]
The control device 41 stores the sensor data detected by the parameter sensor and the additional sensor in the sensor data storage unit 42 during the actual device manufacturing process of the plasma processing apparatus 11 , and the processing unit 43 performs the processing based on the stored sensor data. A device is manufactured by causing the plasma processing apparatus 11 to perform an etching process on the semiconductor wafer W. At this time, the sensor data storage unit 44 stores sensor data detected by the parameter sensor and the additional sensor, and the device data storage unit 46 stores device data detected by the device data detection unit. The stored sensor data and apparatus data are associated as time series of events that are actual processing steps of the plasma processing apparatus 11 for each ID number assigned to the semiconductor wafer W in advance.
[0036]
On the other hand, the control device 41 can perform an operation simulation of the plasma processing apparatus 11 as described below when the plasma processing apparatus 11 is not in the actual process of device manufacture.
[0037]
That is, when the ID number of an arbitrary semiconductor wafer W is input to the input / output device 51 when it is not during the actual processing of the plasma processing apparatus 11, each ID number is input to the sensor data storage unit 44 and the apparatus data storage unit 46, respectively. Sensor data and device data corresponding to the input ID number are selected from the sensor data and device data stored in association with each other in time series of events, and the selected sensor data is sent to the sensor simulator 45, the device data is transmitted respectively to the device simulator 47, the sensor simulator 45 and device simulator 47 performs a virtual treatment of the semiconductor wafer W corresponding to the selected ID number in the same manner as in the actual processing of the above, the virtual process Sensor data is stored in the sensor data storage unit 42 based on the stored sensor data. Processing unit 43 is simulated to perform predetermined processing.
[0038]
An operation performed by the control device 41 in the present embodiment will be described below.
[0039]
At the time of actual processing of the plasma processing apparatus 11, the control apparatus 41 stores sensor data from the parameter sensor and the additional sensor in the sensor data storage unit 42, and the processing unit 43 stores a variation allowable range group stored in advance. Is compared with the sensor data stored in the sensor data storage unit 42 to determine whether or not a device that satisfies the expected specifications is manufactured by normal etching.
[0040]
The variation allowable range group is configured by a data group of sensor data when etching that satisfies the expected specification is performed. This variation tolerance range group is composed of a range of maximum and minimum values of sensor data when a device that satisfies the expected specifications is manufactured, and all of the sensor data obtained during actual processing of the semiconductor wafer W is the maximum value. If it is within the range of the minimum value, it can be determined that a good device satisfying the expected specifications has been manufactured because of normal etching, and any one of the sensor data during actual processing is the above. When it is not within the range, it can be determined that a defective device that does not satisfy the expected specifications is manufactured by abnormal etching.
[0041]
The variation tolerance range group is created using a trial semiconductor wafer w (so-called “dummy wafer”) before the actual processing of the plasma processing apparatus 11. The trial semiconductor wafer w has the same material and structure as the semiconductor wafer W. First, the specification of the trial semiconductor ware w before etching, the specification of the device after etching of the trial semiconductor wafer w, the expected specification of the device, the tolerance of the expected specification, and the characteristic library of the plasma processing apparatus are created. Based on the above, the apparatus parameter that seems to be optimal is obtained by a method similar to the conventional method.
[0042]
The specifications of the trial semiconductor wafer w include specifications of the base material (film type, film thickness, structure, manufacturing method, etc.), specifications of the film to be etched (film type, film thickness, structure, manufacturing method, etc.), and mask material specifications. (The film type, film thickness, mask pattern, etc.) The expected specifications of the device include the pattern width of the device shape surface, etching depth, taper angle, bowing degree, mask material etching amount, etc. Characteristics include wiring resistance, contact and resistance, charge amount, leakage current, and dielectric breakdown. The characteristic library specifications of the plasma processing apparatus 11 include the model of the plasma processing apparatus 11, the processing chamber, the electrode structure, and the high-frequency current. The optimum apparatus parameters are obtained by conventional knowledge and experiments based on these specifications.
[0043]
Using the optimum apparatus parameters obtained as described above, an apparatus parameter variation allowable range and a sensor data variation allowable range group are obtained by an experimental design method or the like. That is, etching is actually performed on the trial semiconductor wafer w based on a plurality of apparatus parameters that are expected to satisfy the expected specification of the device centering on the optimum apparatus parameters, and the apparatus parameter variation allowable range and the sensor data variation Find tolerance group.
[0044]
Etching is performed using the trial semiconductor wafer w by changing the parameters of each apparatus to the maximum, minimum, and between them. At this time, the electric measuring instruments 17, 20, gas flow sensors 27, 29, temperature sensor 13b, pressure sensor 12a and sensor data from the plasma emission spectrometer 31 are stored in the sensor data storage unit 42 for each trial semiconductor wafer w. At the same time, the sensor data storage unit 42 uses the sensor sensor detection values and the additional sensor detection values. For each of these, arithmetic processing is performed for each of them, and an average value is calculated and stored for each trial semiconductor wafer w.
[0045]
As described above, the variation allowable range group is a set of sensor data obtained when an etching process is performed on a predetermined trial semiconductor wafer w based on a predetermined apparatus parameter, and the sensor data is the variation allowable range. When it is within the group, it can be determined that a device having the expected specifications is manufactured.
[0046]
On the other hand, when the plasma processing apparatus 11 is not in actual processing, the control device 41 stores sensor data during actual processing of the plasma processing apparatus 11 when the ID number of the semiconductor wafer W is arbitrarily input to the input / output device 51. Corresponding to the input ID number from the sensor data and the device data stored in the unit 44 and the device data storage unit 46 in association with each ID number of the semiconductor wafer W in time series of actual processing events. Sensor data and device data are selected, and the selected sensor data is transmitted to the sensor data simulator 45, and the selected device data is transmitted to the device data simulator 47. Next, the sensor data simulator 45 transmits the sensor data, the device data simulator 47 transmits the device data to the processing unit 43, and the processing unit 43 compares the pre-stored variation allowable range group with the received sensor data. The operation simulation of the plasma processing apparatus 11 is performed by determining whether or not a device satisfying the expected specifications is manufactured by normal etching.
[0047]
In the present embodiment, the control device 41 predicts the processing result of the plasma processing apparatus 11 by comparing the fluctuation tolerance range stored in advance with the sensor data, but the processing performed by the control device 41 is limited to this. For example, the processing of the plasma processing apparatus 11 is monitored.
[0048]
【The invention's effect】
As described above in detail, according to the plasma etching apparatus simulation apparatus and claim 4, wherein according to claim 1, the sensor data storage unit, a plasma etching apparatus a plurality of processing parameters measured by the plurality of sensors stored in association with the time series of the actual processing of the event, the sensor data simulator, because simulated actuates the plasma etching apparatus based on the associated process parameters, thereby actually operating the plasma etching apparatus A series of operations of the plasma etching apparatus can be confirmed.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a plasma etching apparatus according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a schematic configuration of a simulation apparatus according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Plasma processing apparatus 31 Plasma emission spectrometer 41 Control apparatus 42 Sensor data storage part 43 Processing part 44 Apparatus data storage part 45 Sensor simulator 46 Apparatus data storage part 47 Apparatus simulator 48 CPU
51 I / O device

Claims (2)

In a plasma etching apparatus simulation apparatus connected to a plasma etching apparatus for processing a semiconductor wafer and performing an operation simulation of the plasma etching apparatus,
The simulation apparatus includes a CPU, a plurality of sensors controlled by the CPU, a sensor data storage unit, and a sensor data simulator.
The plurality of sensors measure a plurality of processing parameters during actual processing of the semiconductor wafer by the plasma etching apparatus,
The sensor data storage unit associates and stores a plurality of measured processing parameters in time series of actual processing events of the plasma etching apparatus,
The sensor data simulator operates the plasma etching apparatus in a simulated manner based on the associated processing parameter,
The processing parameters include the temperature of the processing chamber, the pressure of the processing chamber, the characteristic value of the high frequency power source applied to the processing chamber, the supply amount of the etching gas supplied to the processing chamber, and the processing chamber. and the supply amount of the carrier gas supplied, the end point of the etching process seen including,
The characteristic value of the high frequency power source, a high frequency voltage, and the high frequency current, and the high-frequency phase, simulation and wherein the free Mukoto and the high frequency impedance device. A plasma etching apparatus that processes a semiconductor wafer and includes a simulation apparatus,
The simulation apparatus includes a CPU, a plurality of sensors controlled by the CPU, a sensor data storage unit, and a sensor data simulator.
The plurality of sensors measure a plurality of processing parameters during actual processing of the semiconductor wafer by the plasma etching apparatus,
The sensor data storage unit associates and stores a plurality of measured processing parameters in time series of actual processing events of the plasma etching apparatus,
The sensor data simulator operates the plasma etching apparatus in a simulated manner based on the associated processing parameter,
The processing parameters include the temperature of the processing chamber, the pressure of the processing chamber, the characteristic value of the high frequency power source applied to the processing chamber, the supply amount of the etching gas supplied to the processing chamber, and the processing chamber. and the supply amount of the carrier gas supplied, the end point of the etching process seen including,
The characteristic value of the high frequency power source, a plasma etching apparatus for a high frequency voltage, and the high frequency current, and the high-frequency phase, characterized in including Mukoto and the high frequency impedance.

Images