JPH10321598A - Semiconductor device manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the water treating conductions of the same type of many semiconductor device manufacturing devices constant by compensating the individual differences among the manufacturing devices by providing a high-frequency power source connected to a first electrode through a matching circuit and an impedance measuring and adjusting means having an impedance adjusting circuit connected to a second electrode. SOLUTION: High-frequency power from a high-frequency power source 5 is efficiently supplied to a plasma treating chamber 4 by connecting a matching circuit 6 to the lower electrode 2 of the chamber 2. Then an impedance measuring and adjusting device 20 having an impedance adjusting circuit 17 is provided between a ground 16 and an upper electrode 3 and an impedance is automatically adjusted while the impedance is displayed on a displaying section 21 so as to suppress the individual differences among many devices. When the impedance becomes a prescribed value, a wafer 1 is treated with plasma by connecting the adjusting circuit 17 to the upper electrode 3 and ground 16 by means of change-over switches 18a and 18b. Therefore, uniform plasma treatment can be performed among the devices even when the wafer treating condition is not changed at every device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing a semiconductor device, and more particularly to an apparatus for supplying high frequency power to generate plasma.

[0002]

2. Description of the Related Art In a dry etching apparatus for forming, for example, a pattern on a semiconductor wafer (hereinafter, referred to as a wafer) in a manufacturing stage of a semiconductor device, in order to efficiently supply power from a high-frequency power supply to a plasma processing chamber, a power supply between the two is required. Is provided with a matching circuit. Further, JP-A-60-206028
Japanese Patent Application Laid-Open Publication No. H11-163,055 discloses a technique for stabilizing plasma discharge during processing by monitoring plasma impedance in a plasma processing chamber and feeding it back to a gas supply system. This prior art will be described with reference to FIG.

In the prior art dry etching apparatus shown in FIG. 2, a plasma processing chamber 4 having a lower electrode 2 for mounting a wafer 1 and an upper electrode 3 grounded, a high frequency power supply 5 for supplying high frequency power, and a variable coil A matching circuit 6 having 6 a and variable capacitors 6 b and 6 c to match the power from the high-frequency power supply 5 and a power meter 14 are provided.

Further, an arithmetic and control unit 7 for calculating the impedance in the plasma processing chamber 4 from the potential difference between both ends of the variable coil 6a in the matching circuit 6, and an arithmetic and control unit based on the clock B supplied with each data from the matching circuit 6 7, a comparator 8 for comparing the signal from the arithmetic control unit 7 with the impedance variation allowable value A, and a signal from the arithmetic control unit 7 to turn on / off the high-frequency power supply 5.
A switch 9 for FF, a valve 11 for adjusting the flow rate of the etching gas 10, a flow controller 12 for opening and closing this valve, and a display 13 for constantly monitoring the impedance in the plasma processing chamber 4 are provided. With such a configuration, the plasma impedance is sampled and the flow rate of the etching gas 10 is adjusted to suppress the plasma impedance fluctuation.

[0005]

However, the above-mentioned prior art is effective for each manufacturing apparatus,
When used in a mass production factory for semiconductor devices, the following problems occur.

That is, in a mass production factory, many (several to several tens) manufacturing apparatuses of the same model are installed and used. in this case,
If these manufacturing apparatuses and installation conditions are completely the same, it is possible to collectively manage all the apparatuses in plasma processing under the same processing conditions.

However, in practice, variations in the parts of the manufacturing apparatus, variations in the manufacturing process of the manufacturing apparatus, and variations in the installation conditions such as the impedance between the upper electrode and the installation cause variations in the impedance of the manufacturing apparatus itself between the manufacturing apparatuses. That is, a device individual difference occurs.

Therefore, it becomes impossible to manage all the wafers collectively under the same processing conditions, and the processing conditions such as gas flow rate and applied voltage are changed for each individual manufacturing apparatus according to the individual difference of the apparatus. Used.

To change the conditions, it is necessary to check the finished shape of the wafer after the processing, so that it takes time to determine the conditions, and it is necessary to perform it every time parts are replaced during regular maintenance. It is a factor that reduces productivity.

[0010] Accordingly, an object of the present invention is to make it possible to stabilize wafer processing conditions by easily compensating even if there is an individual difference between a large number of manufacturing apparatuses of the same model, thereby improving productivity. It is an object of the present invention to provide a semiconductor device manufacturing apparatus which improves the performance.

[0011]

A feature of the present invention is that a plasma processing chamber having first and second electrodes opposed to each other is provided, and a high-frequency power supply connected to the first electrode via a matching circuit. And an impedance measuring / adjusting means having an impedance adjusting circuit connected to the second electrode. Here, the impedance measurement / adjustment means may include a measurement / control unit that measures the impedance of the impedance adjustment circuit and adjusts the impedance. In this case, a first and a second switch are provided between the impedance adjustment circuit and the measurement / control unit for connecting the impedance adjustment circuit and the measurement / control unit. Preferably, a circuit is separated from the measurement / control unit and connected between the second electrode of the plasma processing chamber and a fixed potential. Further, the impedance adjustment circuit can be configured to include a variable capacitor and a variable coil.

According to the present invention, by adjusting the impedance of the impedance adjustment circuit, the impedance of the device itself can be made constant among a large number of devices, and the individual differences between the devices can be absorbed. There is no need to change the processing conditions in each device, and productivity is improved.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, a plasma processing chamber 4 includes a lower electrode 2 on which the wafer 1 is mounted, and an upper electrode 3 connected to the ground terminal 16 and arranged opposite to the lower electrode. The chamber is evacuated so as to be constant at a pressure of about 3.0 Torr, and an etching gas having a constant flow rate flows from a gas inflow system (not shown).

By matching the high-frequency power from the high-frequency power supply 5, a matching circuit 6 for efficiently supplying the high-frequency power to the plasma processing chamber is coupled to the lower electrode 2 of the plasma processing chamber. Wattmeter 14 between
Is provided.

That is, the matching circuit 6 includes a variable coil 6a and variable capacitors 6b and 6c. The matching circuit 6 is supplied from the high-frequency power source 5 so that high-frequency power is efficiently consumed by plasma during etching. The variable coil 6a is variable so that the power (reflected wave output) returning from the plasma processing chamber 4 to the high frequency power supply 5 through the matching circuit 6 with respect to the power (traveling wave output) passing through the plasma processing chamber 4 to the plasma processing chamber 4 is minimized. It has a function of automatically adjusting the capacitors 6b and 6c to perform impedance matching (auto-matching function).

Further, in the present invention, the ground (ground terminal) 16
An impedance measuring / adjusting device (means) 20 having an impedance adjusting circuit 17 connected between the terminal and the terminal of the upper electrode 3 is provided. The impedance measurement / adjustment device 20 includes a measurement / control unit 19 having a measurement unit 19a and a control unit 19b in addition to the impedance adjustment circuit 17, a display unit 21, and a pair of changeover switches 18
a and 18b are provided.

The changeover switches 18a and 18b enable the impedance adjustment circuit 17 to switch between connection to the ground 16 and the upper electrode 3 and connection to both ends of the impedance measurement / control section 19.

The impedance adjusting circuit 17 has a variable coil 17a and a variable capacitor 17b.

When the impedance of the impedance adjustment circuit 17 is measured, the changeover switches 18a and 18
b, the impedance adjustment circuit 17 is disconnected from the ground 16 and the terminal of the upper electrode 3 and connected to the measurement / control unit 19, and the impedance is measured by the measurement unit 19a.
The measured value is displayed on the display unit 21.

The control unit 19b adjusts the variable coil 17a and the variable capacitor 17b in the impedance adjustment circuit 17 based on the measurement value of the measurement unit 19a so that the impedance of the impedance adjustment circuit 17 becomes a predetermined value.
In other words, when the impedance adjustment circuit 17 is connected between the upper electrode and the ground, the impedance is automatically adjusted while displaying on the display unit 21 a value that suppresses individual differences among many devices.

Then, the impedance adjusting circuit 17 whose impedance has a predetermined value is switched to a switch 18.
a, 18b, disconnect from the measurement / control unit 19, insert and connect between the terminal of the upper electrode 3 and the terminal of the ground 16,
Plasma processing is performed on the wafer 1 in the plasma processing chamber 4.

[0023]

As described above, according to the present invention, since the impedance measuring / adjusting means capable of easily changing the impedance of the apparatus itself is provided, it is possible to suppress individual differences between a large number of manufacturing apparatuses of the same model. Accordingly, uniform plasma processing can be performed between apparatuses without changing wafer processing conditions in each apparatus, and productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a plasma processing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a conventional plasma processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wafer 2 Lower electrode 3 Upper electrode 4 Plasma processing chamber 5 High frequency power supply 6 Matching circuit 6a Variable coil 6b, 6c Variable capacitor 7 Operation / control part 8 Comparator 9 Switch 10 Etching gas 11 Valve 12 Flow controller 13 Display 14 Power Total 15 Data sampling circuit 16 Ground (ground terminal) 17 Impedance adjustment circuit 17a Variable coil 17b Variable capacitor 18a, 18b Switch 19 Measurement / control unit 19a Measurement unit 19b Control unit 20 Impedance measurement / adjustment device 21 Display unit

Claims (5)

[Claims] 1. A plasma processing chamber having first and second electrodes opposed to each other, a high-frequency power supply connected to the first electrode via a matching circuit, and a high-frequency power supply connected to the second electrode. And an impedance measuring / adjusting means having an impedance adjusting circuit. 2. The semiconductor device according to claim 1, wherein said impedance measurement / adjustment means includes a measurement / control unit for measuring the impedance of said impedance adjustment circuit and adjusting the impedance. Manufacturing equipment. 3. The semiconductor device according to claim 2, further comprising a first switch and a second switch connected between the impedance adjustment circuit and the measurement / control unit. apparatus. 4. The method according to claim 1, wherein the first and second changeover switches disconnect the impedance adjustment circuit from the measurement / control unit and connect the impedance adjustment circuit between the second electrode of the plasma processing chamber and a fixed potential. Claim 3
An apparatus for manufacturing a semiconductor device as described in the above. 5. The semiconductor device manufacturing apparatus according to claim 1, wherein said impedance adjustment circuit has a variable capacitor and a variable coil.