KR20000039511A - Matching unit for rf power - Google Patents

Abstract

PURPOSE: A matching unit for an RF power is provided to accurately transfer the RF power to a chamber. CONSTITUTION: A matching unit for an RF power comprises a phase/amplitude detector(1), a serial capacitor(C1), an inductive coupling resonator(R), a servo card(3), first and second position sensors(9a,9b) and a variable resistor(5). The phase/amplitude detector(1) senses the phase/amplitude of RF power to output the sensed value. The capacitor(C1) and the inductive coupling resonator(R) are connected to the output end of the detector(1). The servo card(3) controls the capacitances of the serial capacitor and a parallel capacitor. The position sensors(9a,9b) sense the capacitances of the serial and parallel capacitors to set first and second home positions, respectively.

Description

Radio Frequency Power Matching Unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to equipment used to fabricate semiconductor devices, and more particularly, to RF power matching of semiconductor device manufacturing equipment for etching material films formed on semiconductor substrates.

In manufacturing a semiconductor device, an etching process is essential. The etching process is classified into a wet etching process and a dry etching process, and a dry etching process is widely used for etching a highly integrated semiconductor device requiring a fine pattern. The dry etching process is performed in a hermetically sealed chamber, and supplies the radiofrequency power to the electrode in the hermetically sealed chamber and injects an etching gas to react the etching gas with the material film on the semiconductor substrate in a plasma state.

A general dry etching apparatus includes a chamber, a radio frequency power generator for generating radio frequency power for application to electrodes in the chamber, and a radio frequency power matching unit between the chamber and the radio frequency power generator. The lidao frequency power matching unit has a function for accurately delivering the radio frequency power generated from the radio frequency power generator to the chamber.

1 is a circuit diagram of a conventional radio frequency power matching unit.

1, a radio frequency power generator (not shown) and a phase / amplitude detector 1 are connected, and the phase / amplitude detector 1 is a phase and amplitude of radio frequency power generated from a radio frequency power generator. Detects the size of The output of the phase / amplitude detector 1 is connected with a series capacitor C1 and an inductively coupled resonator R. The inductive coupling resonator R includes a parallel capacitor C2 and a second induction coil L2 connected in series, and a capacitor C connected in parallel with the parallel capacitor C2 and the second induction coil L2. In addition, the series capacitor C1 is connected to a first induction coil L1, and the first induction coil L1 is connected to an electrode in a chamber (not shown). The phase / amplitude detector 1 senses the phase and amplitude of the radio frequency power generated from the radio frequency power generator and feeds it back to the servo card 3, and the servo card 3 compensates for the detected phase and amplitude. To adjust the capacitance of the series capacitor C1 and the parallel capacitor C2 through the first and second motors 7a and 7b. The first and second position detectors 9a and 9b for detecting a position at the time of matching the radio frequency from the capacitors of the series capacitor C1 and the parallel capacitor C2 feed back to the servo card 3.

The above-described conventional radio frequency power matching unit is difficult to accurately transmit radio frequency power to the chamber because the capacity of the initial series capacitor and the capacity of the parallel capacitor are set to constant values when the radio frequency power is applied. As a result, process defects are caused, as well as damage to the radio frequency matching unit.

It is an object of the present invention to provide a radio frequency power matching unit capable of accurately delivering radio frequency power to a chamber.

1 is a circuit diagram of a conventional radio frequency power matching unit.

2 is a circuit diagram of a radio frequency power matching unit according to the present invention.

In order to achieve the above object, the present invention provides a phase / amplitude detector for sensing a phase / amplitude of radio frequency power and outputting a result, a series capacitor connected to an output terminal of the phase / amplitude detector, and the phase / amplitude A servo card for adjusting the capacitance of the series capacitor and the parallel capacitor constituting the inductively coupled resonator by inputting an inductively coupled resonator connected to an output terminal of the detector and a phase difference sensed from the phase / amplitude detector; A first position sensor configured to sense a capacitance of the capacitor to set a first home position and to feed back the set first home position to the servo card, and set a second home position by sensing the capacitance of the parallel capacitor A second position sensor for feeding back the set second home position to the servo card; And a variable resistor capable of varying the capacity of the parallel capacitor.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a circuit diagram of a radio frequency power matching unit according to the present invention. Here, portions denoted by the same reference numerals as those in FIG. 1 denote the same members.

Referring to FIG. 2, an output terminal of the phase / amplitude detector 1 which detects the phase and amplitude of radio frequency power generated from a radio frequency power generator (not shown) and outputs the detected result is a series capacitor C1. Connected with. The series capacitor C1 is connected to a first induction coil L1, and the first induction coil L1 is connected to an electrode installed in a chamber (not shown) of a semiconductor manufacturing equipment, that is, an etching equipment. Also, the output terminal of the phase / amplitude detector 1 is connected to the inductively coupled resonator R. The inductively coupled resonator R may include a second induction coil L2 connected in series with a parallel capacitor C2, a parallel capacitor C2 connected in series, and a capacitor C connected in parallel to both ends of the second induction coil L2. It consists of The phase difference sensed by the phase / amplitude detector 1 is transmitted to the servo card 3, and the servo card 3 compensates for the phase difference so that the series capacitor (1) through the first and second motors 7a and 7b can be used. The capacity of C1) and the parallel capacitor C2 is adjusted. In this case, the series capacitor C1 and the parallel capacitor C2 are initialized to have a capacity of a predetermined value or less, so that the maximum capacity is limited. The first and second position detectors 9a and 9b for sensing the capacitance of the series capacitor C1 and the parallel capacitor C2 and setting the home position in matching radio frequencies from the sensed capacitance are The set home position is fed back to the servo card 3. In this case, since the capacitance of the series capacitor C1 and the parallel capacitor C2 does not vary above a limited value, the radio frequency power generated from the radio frequency power generator may not be accurately transmitted to the electrode in the chamber. Therefore, by additionally providing a variable resistor (5) that can vary the capacitance of the series capacitor (C1) and parallel capacitor (C2), it is possible to accurately transmit radio frequency power to the electrode in the chamber. The variable resistor (5) is preferably mounted in the servo card (3), the variable resistance regulator 11 that can adjust the variable resistor (5) to the outside of the etching equipment so that the operator can operate from the outside. It is preferable to install.

The present invention is not limited to the above embodiments, and modifications and improvements are possible at the level of those skilled in the art.

According to the present invention as described above, by providing a variable resistor capable of varying the capacity of the series capacitor and the parallel capacitor, it is possible to accurately transmit the radio frequency power generated from the radio frequency power generator to the electrode in the chamber.

Claims (1)

A phase / amplitude detector which senses the magnitude of the phase / amplitude of the radio frequency power and outputs the result; A series capacitor connected to the output terminal of the phase / amplitude detector; An inductively coupled resonator connected to an output of the phase / amplitude detector; A servo card that adjusts the capacitance of the series capacitor and the capacitance of a parallel capacitor constituting the inductively coupled resonator by inputting a phase difference sensed from the phase / amplitude detector; A first position sensor for sensing a capacitance of the series capacitor to set a first home position and to feed back the set first home position to the servo card; A second position sensor for sensing a capacitance of the parallel capacitor to set a second home position and to feed back the set second home position to the servo card; And And a variable resistor capable of varying the capacitance of the series capacitor and the parallel capacitor.