PLASMA PROCESSING DEVICE AND METHOD OF MONITORING DISCHARGE STATE IN PLASMA PROCESSING DEVICE
First Claim
1. A plasma processing device comprising:
- a vacuum chamber that forms a processing chamber;
an electrode portion arranged in the processing chamber and electrically isolated from the vacuum chamber;
an vacuum exhaust portion configured to exhaust a gas from the processing chamber by vacuum;
a gas supply portion configured to supply a gas which is used for plasma generation into the processing chamber;
a high frequency power supply portion configured to generate plasma discharge in the processing chamber when a high frequency voltage is impressed onto the electrode portion;
a matching device configured to match an impedance of a plasma discharge circuit configured to generate the plasma discharge with an impedance of the high frequency power supply portion;
a discharge detection sensor comprising, at least, a plate-shaped dielectric member arranged such that one surface thereof opposes plasma discharge generated in the processing chamber, and a probe electrode arranged on the other surface of the dielectric member; and
a signal analyzing portion configured to detect a signal of a potential change induced in the probe electrode in response to a change in the plasma discharge and execute analysis processing for monitoring a state of discharge, wherein said plasma processing device is configured to execute plasma processing for an object to be processed which is placed on the electrode portion to plasma processing, andwherein the signal analyzing portion comprises;
a first detector configured to detect a signal of a potential change induced by first arc discharge generated between the electrode portion and the object to be processed;
a second detector configured to detect a signal of a potential change induced by second arc discharge other than the first arc discharge; and
an abnormal discharge determining portion configured to obtain a difference between a number of detections by the first detector and a number of detections by the second detector within predetermined time and to determine whether there is a possibility of generation of abnormal discharge in the processing chamber based on the difference.
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Accused Products
Abstract
An object is to provide a plasma processing device capable of properly monitoring a state of plasma discharge and detecting a precursor to abnormal discharge, and a method of monitoring the state of discharge in the plasma processing device. In analysis processing for monitoring executed by detecting, by a signal analyzing portion 30, a signal of a potential change induced in a discharge detection sensor 23 in response to a change in plasma discharge of the inside of a processing chamber and recorded in a signal recorder 20, based on a counter value N3 obtained by detecting a signal of abnormal discharge (first arc discharge) generated between an electrode portion and an object to be processed by a first detector 33 and a counter value N4 obtained by detecting a signal of micro-arc discharge (second arc discharge) generated by deposition of a foreign substance in the processing chamber by a second detector 35, an abnormal discharge determining portion 39 calculates a difference (N3−N4) and compares the difference (N3−N4) with a threshold value a2 for determination and determines whether there is a possibility of generation of abnormal discharge in the processing chamber.
17 Citations
6 Claims
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1. A plasma processing device comprising:
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a vacuum chamber that forms a processing chamber; an electrode portion arranged in the processing chamber and electrically isolated from the vacuum chamber; an vacuum exhaust portion configured to exhaust a gas from the processing chamber by vacuum; a gas supply portion configured to supply a gas which is used for plasma generation into the processing chamber; a high frequency power supply portion configured to generate plasma discharge in the processing chamber when a high frequency voltage is impressed onto the electrode portion; a matching device configured to match an impedance of a plasma discharge circuit configured to generate the plasma discharge with an impedance of the high frequency power supply portion; a discharge detection sensor comprising, at least, a plate-shaped dielectric member arranged such that one surface thereof opposes plasma discharge generated in the processing chamber, and a probe electrode arranged on the other surface of the dielectric member; and a signal analyzing portion configured to detect a signal of a potential change induced in the probe electrode in response to a change in the plasma discharge and execute analysis processing for monitoring a state of discharge, wherein said plasma processing device is configured to execute plasma processing for an object to be processed which is placed on the electrode portion to plasma processing, and wherein the signal analyzing portion comprises; a first detector configured to detect a signal of a potential change induced by first arc discharge generated between the electrode portion and the object to be processed; a second detector configured to detect a signal of a potential change induced by second arc discharge other than the first arc discharge; and an abnormal discharge determining portion configured to obtain a difference between a number of detections by the first detector and a number of detections by the second detector within predetermined time and to determine whether there is a possibility of generation of abnormal discharge in the processing chamber based on the difference. - View Dependent Claims (2, 3)
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4. A method of monitoring a state of discharge in a plasma processing device, the plasma processing device comprising:
- a vacuum chamber that forms a processing chamber;
an electrode portion arranged in the processing chamber and electrically isolated from the vacuum chamber;
an vacuum exhaust portion configured to exhaust a gas from the processing chamber vacuum;
a gas supply portion configured to supply a gas which is used for plasma generation into the processing chamber;
a high frequency power supply portion configured to generate plasma discharge in the processing chamber when a high frequency voltage is impressed onto the electrode portion;
a matching device configured to match an impedance of a plasma discharge circuit configured to generate the plasma discharge with an impedance of the high frequency power supply portion; and
a discharge detection sensor comprising, at least, a plate-shaped dielectric member attached to the vacuum chamber such that one surface thereof opposes plasma discharge generated in the processing chamber, and a probe electrode arranged on the other surface of the dielectric member, wherein said plasma processing device monitors the state of the plasma discharge in the processing chamber, said method comprising;a signal recording step of receiving a signal of a potential change induced in the probe electrode in response to a change in the plasma discharge, and temporarily storing the signal as signal data indicating the potential change, and a signal analysis step of executing analysis processing for monitoring a state of the plasma discharge with reference to the temporarily stored signal data, wherein the signal analysis step comprises; detecting, by a first detector, a signal of a potential change induced by first arc discharge generated between the electrode portion and an object to be processed; detecting, by a second detector, a signal of a potential change induced by second arc discharge other than the first arc discharge; obtaining a difference between a number of detections by the first detector and a number of detections by the second detector within predetermined time; and determining whether there is a possibility of generation of abnormal discharge, based on the difference. - View Dependent Claims (5, 6)
- a vacuum chamber that forms a processing chamber;
Specification