Plasma monitoring method and plasma monitoring system
View Patent ↗A plasma monitoring method using a sensor, the sensor having a substrate; a first electrode, the first electrode being a conductive electrode and formed on the substrate while being isolated from the substrate; an insulating film formed on the first electrode; a contact hole formed in the insulating film and having a depth from a surface of the insulating film to the first electrode; and a second electrode, the second electrode being a conductive electrode, formed on the surface of the insulating film, and faced to plasma during a plasma process, the plasma monitoring method including measuring and monitoring potentials of the first electrode and the second electrode or a potential difference between the first electrode and the second electrode during the plasma process is disclosed. A plasma monitoring system carrying out the plasma monitoring method is also disclosed.
1. A plasma monitoring system comprising:
sensors each having
a substrate;
a first electrode formed on the substrate;
an insulating film that is formed on the first electrode and has a contact hole formed therein, the contact hole exposing a part of a surface of the first electrode; and
a second electrode that is formed on the insulating film and is electrically separated from the first electrode, and facing a plasma during a plasma process;
voltmeters monitoring the plasma during the plasma process by measuring, for each respective sensor of the sensors, potentials of the respective first electrode and the respective second electrode, or a potential difference between the respective first electrode and the respective second electrode to determine charge-up; and
a determination unit determining a dependence of charge-up on a pattern-ratio by comparing charge-up changes during a first plasma processing of the plasma process and a second plasma processing of the plasma process, wherein the second plasma processing is performed before the first plasma processing or after the first plasma processing,
wherein in the first plasma processing, a plurality of the sensors is arranged and bonded on a first wafer,
wherein in the second plasma processing, a group of the sensors is arranged and bonded at a plurality of different positions on a second wafer, a total number of the group of the sensors arranged and bonded on the second wafer is different from a total number of the plurality of sensors arranged and bonded on the first wafer.
2. The plasma monitoring system of claim 1 , further comprising another wafer upon which at least one of the sensors is arranged at each of one or more predetermined positions.
3. The plasma monitoring system of claim 2 , further comprising:
a plasma chamber accommodating the another wafer, and irradiating the another wafer with a plasma during the plasma process.
4. The plasma monitoring system of claim 1 ,
wherein each of the sensors has one or more third electrodes arranged between the first electrode and the second electrode and electrically isolated from the first electrode and the second electrode, and
the voltmeters measure for each sensor, potentials of the respective first electrode, the respective second electrode, and the respective one or more third electrodes, or a potential difference among the respective first electrode, the respective second electrode, and the respective one or more third electrodes.
5. The plasma monitoring system of claim 2 ,
wherein each of the sensors has one or more third electrodes arranged between the first electrode and the second electrode and electrically isolated from the first electrode and the second electrode, and
the voltmeters measure for each sensor, potentials of the respective first electrode, the respective second electrode, and the respective one or more third electrodes, or a potential difference among the respective first electrode, the respective second electrode, and the respective one or more third electrodes.
6. The plasma monitoring system of claim 3 ,
wherein each of the sensors has one or more third electrodes arranged between the first electrode and the second electrode and electrically isolated from the first electrode and the second electrode, and
the voltmeters measure for each sensor, potentials of the respective first electrode, the respective second electrode, and the respective one or more third electrodes, or a potential difference among the respective first electrode, the respective second electrode, and the respective one or more third electrodes.
7. A plasma monitoring system comprising:
sensors each having
a substrate;
a first electrode;
an insulating film that is formed on the first electrode and has a contact hole formed therein, the contact hole exposing a part of a surface of the first electrode; and
a second electrode that is formed on the insulating film and is electrically separated from the first electrode, and facing a plasma during a plasma process;
voltmeters monitoring the plasma during first and second plasma processing of the plasma process, by measuring, for each respective sensor of the sensors, potentials of the respective first electrode and the respective second electrode, or a potential difference between the respective first electrode and the respective second electrode to determine charge-up;
a first wafer, wherein in the first plasma processing, a plurality of the sensors is arranged and bonded on the first wafer; and
a second wafer, wherein in the second plasma processing, a group of the sensors is arranged and bonded at a plurality of different positions on the second wafer, a total number of the group of the sensors arranged and bonded on the second wafer is different from a total number of the plurality of the sensors arranged and bonded on the first wafer.