JPH06101071A - Method for microwave plasma treating and device therefor - Google Patents

Abstract

PURPOSE:To uniformly treat a material with plasma by measuring the plasma density distribution, intensifying the measured result and then controlling the plasma operating factor. CONSTITUTION:Plasma is produced by a microwave oscillator 15 to treat a material 90 with the plasma. The data received by the light receiving element system 201 of a plasma density distribution measuring part 200 are picture- processed by an emission intensity ratio picture processing system 205, and the optional range is intensified by a picture data intensifying system 206. The signal is received by a device control part 300, and the operating current 16 of a magnetron 15, a gas flow rate control valve 46 and a gas pressure control valve 80 are controlled, and a uniform plasma is produced. Since the nonuniformity of plasma is apprarently increased by the picture data intensified by the system 206, the material is treated more uniformly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus, and more particularly to a microwave plasma processing method and apparatus suitable for generating uniform plasma using microwaves.

[0002]

2. Description of the Related Art As a publicly known example of a plasma observation system using image processing, Hitachi Ltd. has published technical data on a spectroscopic plasma image observation system. It is shown in this technical document that the data for evaluating the etching uniformity can be obtained from the measurement results by using the spectroscopic plasma image observation system.

[0003]

The above-mentioned prior art has shown that it is possible to evaluate the uniformity of etching by measuring the plasma emission distribution. On the other hand, recent semiconductor devices have been miniaturized more than ever, and there is a demand for more highly accurate plasma treatment with highly uniform plasma.

In the prior art, although data for evaluating the uniformity of etching can be obtained from the result of image processing, there is no feedback of the data indicating the uniformity of plasma to the plasma processing apparatus, so that the uniformity of the object to be processed can be obtained in real time. There was a problem that the plasma treatment was not sufficient.

An object of the present invention is to measure a plasma density distribution,
By using the plasma control mechanism that is composed of the device control unit,
An object of the present invention is to provide a microwave plasma processing method and apparatus capable of uniformly processing an object to be processed by making plasma generated by microwaves uniform.

[0006]

In order to achieve the above object, a uniform plasma is generated by monitoring and controlling the plasma using a plasma control mechanism composed of a plasma density distribution measuring unit and an apparatus control unit. Therefore, the above object is achieved.

[0007]

The microwave plasma processing apparatus according to the present invention comprises a plasma density distribution measuring section and an apparatus control section. The plasma generated by the microwave is measured and monitored by the plasma density distribution measuring unit on the plasma density distribution on the object to be processed, and the processing result is further emphasized in an arbitrary range. The plasma operating factors such as the processing pressure and the gas flow rate are controlled to further homogenize the plasma distribution. Therefore, the object to be processed can be uniformly plasma-processed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a configuration diagram of a microwave plasma processing apparatus to which the present invention is applied, and FIG. 2 is a diagram showing a configuration of a plasma density distribution measuring unit.

In FIG. 1, the plasma generating chamber 40 and the processing chamber 60 of the microwave plasma processing apparatus are kept in vacuum and are partitioned by a porous plate 50 made of aluminum. In this case, the means for converting the introduced gas into plasma is carried out by utilizing microwaves, an opening is provided in the plasma generation chamber 40, and a window 30 made of quartz is attached to the opening so that the end portion of the microwave waveguide 20 is provided. Is provided with a microwave oscillator 15.

The exhaust means is connected to the exhaust port 70 of the processing chamber 60, and comprises a pressure control valve 80 and a vacuum pump (not shown). The gas supply unit is connected to the plasma generation chamber 40 from a gas supply source (not shown) via the flow rate control valve 46 and the gas supply source 44. An object 90 to be processed is loaded into the processing chamber 60 and placed on the sample table 100.

On the other hand, the plasma control mechanism is composed of a plasma density distribution measuring unit 200 and an apparatus control unit 300. Further, the plasma density distribution measuring unit 200 has a condenser lens 202, an interference filter 203 and a CCD camera as shown in FIG. A light receiving element system 201 composed of 204 and a computer inside, and a light emission intensity ratio image processing system 205 capable of image image processing and an arbitrary range of data obtained from the light emission intensity ratio image processing system 205 are further enhanced. It is composed of the image data enhancement processing system 206.

The apparatus control unit 300 operates the current 16 for the magnetron 15, the gas flow rate control valve 46, and the gas pressure control valve 8 based on the processing result of the plasma density distribution measurement unit.
The configuration is such that 0 operation is possible.

With the device having the configuration shown in FIGS. 1 and 2,
Frequency 2.45GH generated from microwave oscillator 15
The microwave of z travels in the microwave waveguide 20 and is guided into the plasma generation chamber 40 through the window 30 made of quartz. Microwaves are applied to the processing gas introduced into the plasma generation chamber 40, and plasma is generated in the plasma generation chamber 40. A perforated plate 50 made of aluminum is provided between the plasma generation chamber 40 and the processing chamber 60 to prevent microwaves from proceeding to the processing chamber 60 and to mainly guide radical components to the processing chamber 60. There is.

The case where the present invention is applied to a resist ashing process using oxygen gas will be described below. The oxygen plasma light generated in the plasma generation chamber 40 passes through the light receiving element system 201 including the condenser lens 202, the oxygen radical interference filter (wavelength 777 mm) 203, and the CCD camera 204 shown in FIG. The spectral intensity ratio is converted into an electric signal, and the oxygen radical distribution in the oxygen plasma is measured by the emission intensity ratio image processing system 205 having a computer inside.

In order to make the object to be processed uniform, it is important that the oxygen radicals supplied to the object be uniform. The measured radical distribution measurement result is sent to the image data enhancement processing system 206 via a computer. Here, only the arbitrary data range is selected and emphasized. For this reason,
The enhanced image data apparently appears to have increased plasma non-uniformity. Next, based on the image data emphasizing the non-uniformity, it is compared with the radical distribution data having a small non-uniformity which can be preliminarily allowed to be more uniform, and the apparatus control unit 30 is controlled so that the non-uniformity becomes equal to or less than the permissible value.
At 0, the magnetron current, processing pressure and gas flow rate are controlled to generate a sufficiently uniform plasma.

Therefore, by carrying out the present invention, it is possible to achieve uniform plasma treatment of the object to be treated.

Next, a second embodiment will be described with reference to FIG. FIG. 3 shows an example in which the present invention is applied to a microwave coil processing apparatus in which a high frequency power source is added to a solenoid coil 110 capable of generating a magnetic field and an object to be processed in order to add an ion action by a high frequency electric field during plasma processing. It is a figure. In this case, the device control unit 300 'is configured to control the coil current value as well, and the plasma control first controls the coil current value within a preset range, and then controls the magnetron current, the processing pressure, and the gas flow rate. It is configured to properly control the factors of. According to the present embodiment, the plasma generation chamber 4 is used even when the size of the apparatus is increased by using the coil magnetic field and the microwave electric field together.
A high density and uniform plasma can be obtained at 0 ', and there is an effect that a large-diameter object can be processed at high speed and uniformly.

[0018]

According to the present invention, the object to be processed can be uniformly plasma-processed.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a microwave plasma processing apparatus to which the present invention is applied.

FIG. 2 is a diagram showing a configuration of a plasma density distribution measuring unit.

FIG. 3 is a diagram showing a configuration of a microwave plasma processing apparatus showing a second embodiment.

[Explanation of symbols]

15 ... Magnetron, 20 ... Waveguide, 30 ... Quartz window, 4
0, 40 '... Plasma generating chamber, 60 ... Processing chamber, 90 ... Object to be treated, 100 ... Sample stage, 200 ... Plasma density distribution measuring unit, 300, 300' ... Device control unit.

Claims (4)

[Claims] 1. A microwave plasma processing apparatus for introducing a microwave into a vacuum container to plasmaize a processing gas introduced into the container to plasma-process an object to be processed,
A microwave plasma processing method comprising: measuring a plasma density distribution, emphasizing the measurement result in an arbitrary range, and then controlling a plasma operation factor to make the plasma density uniform. 2. A microwave plasma processing apparatus having a plasma control mechanism composed of a plasma density distribution measuring section and an apparatus control section. 3. In a microwave plasma processing apparatus, the plasma density distribution measuring unit measures the plasma density distribution and emphasizes the measurement result, and the apparatus controlling unit controls the magnetron current, the processing pressure, and the gas flow rate. A microwave plasma processing apparatus having the above structure. 4. A microwave plasma processing apparatus in which a solenoid coil capable of generating an external magnetic field is added to the plasma processing apparatus according to claim 3, wherein the apparatus control unit can also control the coil current. And microwave plasma processing equipment.