Substrate processing apparatus and substrate processing method
View Patent ↗To effectively prevent a micro arc causing damage to an apparatus and a substrate, by detecting a generation of the micro arc. A substrate processing apparatus is constituted so as to generate a plasma P, by applying a high frequency power to an electrode 210 provided in a processing chamber 200 from a high frequency power supply part 100 through a matching unit 300 . A directional coupler 121 is provided between a high frequency power source 111 and the matching unit 300 , so that a reflected wave reflected from the electrode 210 and a traveling wave advancing toward the electrode 210 are coupled to a detector 122 . The detector 122 outputs a detection signal, when a level of a reflected wave Pr and a differential level thereof exceed each set value. In order to place an initial period of discharge out of a detection period, a delay traveling wave, which is a delayed traveling wave, is also outputted. A controller 130 determines the generation of a harmful micro arc, when coincidence of three detection signals outputted from the detector 122 is obtained, supplies an RF cut signal to a CPU 116 , and temporarily stops or temporarily decreases a high frequency power from the high frequency power source 111.
1. A substrate processing apparatus, which has a high frequency power supply part with a controllable high frequency power source, applies a high frequency power from the high frequency power source to a discharge electrode provided in a processing chamber through a matching unit, and generates a plasma in the processing chamber, comprising:
a detector that detects a traveling wave of the high frequency power applied to the discharge electrode and a reflected wave of the high frequency power reflected from the discharge electrode between the high frequency power source and the matching unit, or between the matching unit and the discharge electrode; and
a controller that controls the high frequency power source so as to temporarily stop or temporarily decrease an application of the high frequency power to the discharge electrode, in accordance with a detection result of the reflected wave,
wherein
the detector:
outputs a level detection signal when the level of a detection output of the reflected wave is more than a level set value, and outputs a differential detection signal when the level obtained by differentiating a detection output of the reflected wave is more than the differential set value, and a fluctuation of the reflected wave is thereby detected, and
delays a detection output of the traveling wave for a predetermined time period, and
the controller:
controls the high frequency power source so as to temporarily stop or temporarily decrease an application of the high frequency power to the discharge electrode, when the level detection signal and the differential detection signal are simultaneously output from the same detector, and
when the high frequency power is applied again after temporarily stopping or temporarily decreasing the application of the high frequency power to the discharge electrode, controls the high frequency power source so as to continuously apply the high frequency power without temporarily stopping or temporarily decreasing the application of the high frequency power before the predetermined time period passes in accordance with a delaying result of the traveling wave, and after the predetermined time period passes, temporarily stop or temporarily decrease the application of the high frequency power to the discharge electrode when the level detection signal and the differential detection signal are simultaneously outputted from the detector.
2. The substrate processing apparatus according to claim 1 , wherein the controller outputs a control signal as a monitor signal.
3. The substrate processing apparatus according to claim 1 , wherein time for temporarily stopping or temporarily decreasing the high frequency power is 100 to 300 μseconds.