1. A method of removing particles from a chamber of a plasma processing apparatus, wherein the chamber is connected to a gas exhaust port and a plasma of a processing gas is generated in the chamber to plasma process a substrate to be processed, the method comprising:
positively charging the particles at a first region of the chamber by applying a first negative voltage to a first charging electrode installed in a first portion of an inner wall of the chamber;
drift-transferring the positively charged particles towards a second region of the chamber by applying a second negative voltage to a second charging electrode installed in a second portion of the inner wall of the chamber;
guiding the drift-transferred positively charged particles towards the gas exhaust port along the inner wall of the chamber; and
discharging the guided positively charged particles from the chamber through the gas exhaust port,
wherein said applying the first negative voltage attracts positive ions toward the first charging electrode and the particles are positively charged by colliding with the positive ions,
wherein the second portion is closer to the gas exhaust port than the first portion and wherein the second negative voltage has an absolute value greater than the absolute value of the first negative voltage.
2. The method of claim 1, wherein each of the first and the second charging electrode is embedded in an insulator, and
wherein said applying the first negative voltage attracts the positive ions and the particles positively charged by colliding with the positive ions toward the first portion of the inner wall of the chamber.
3. The method of claim 1, wherein the gas exhaust port is disposed around a lower part of the inner wall of the chamber, and the positively charged particles are guided towards the gas exhaust port while moving down along the inner wall of the chamber.
4. The method of claim 3, wherein a baffle plate for providing a gas exhaust path of a low conductance is installed in the vicinity of an entrance side of the gas exhaust port, and a negative potential is applied to the baffle plate.
5. A method for performing a plasma process on a substrate to be processed by generating a plasma of a processing gas in a vacuum evacuable chamber connected to a gas exhaust port, the method comprising:
depressurizing the chamber accommodating the substrate therein;
removing particles generated in the chamber by applying a negative voltage to a charging electrode installed in an inner wall of the chamber;
processing the substrate by generating the plasma in the chamber by way of introducing the processing gas into the chamber and supplying a high frequency power into the chamber;
stopping, after said processing the substrate, said introducing the processing gas and said supplying the high frequency power;
grounding the charging electrode; and
transferring the substrate out of the chamber,
wherein said removing the particles includes:
positively charging particles generated within the chamber by attracting positive ions to an ion sheath region, the ion sheath region being formed in a region other than the vicinity of the substrate when the plasma is generated;
guiding positively charged particles towards the gas exhaust port via the ion sheath region; and
discharging the positively charged particles from the chamber through the gas exhaust port,
wherein the charging electrode is electrically divided into a plurality of regions depending on a distance from the gas exhaust port, and independent negative potentials are applied to the respective regions, and
wherein said applying the negative voltage attracts the positive ions toward the charging electrode and the particles are positively charged by colliding with the positive ions,
wherein the plurality of regions comprise a first region with a first negative voltage and a second region with a second negative voltage, wherein the second region is closer to the gas exhaust port than the first region, and wherein the second negative voltage has an absolute value greater than the absolute value of the first negative voltage.
6. A method for performing a plasma process on a substrate to be processed by generating a plasma of a processing gas in a vacuum evacuable chamber connected to a gas exhaust port, the method comprising:
depressurizing the chamber accommodating the substrate therein;
removing particles generated in the chamber;
processing the substrate by generating the plasma in the chamber by way of introducing the processing gas into the chamber and supplying a high frequency power into the chamber;
stopping, after said processing the substrate, said introducing the processing gas and said supplying the high frequency power;
grounding the charging electrode; and
transferring the substrate out of the chamber,
wherein said removing the particles includes:
positively charging the particles at a first region of the chamber by applying a first negative voltage to a first charging electrode installed in a first portion of an inner wall of the chamber;
drift-transferring the positively charged particles towards a second region of the chamber by applying a second negative voltage to a second charging electrode installed in a second portion of the inner wall of the chamber;
guiding the drift-transferred positively charged particles towards the gas exhaust port along the inner wall of the chamber; and
discharging the guided positively charged particles from the chamber through the gas exhaust port,
wherein an absolute value of the second negative voltage is greater than that of the first negative voltage, and
wherein the first portion is an inner ceiling wall of the chamber and the second portion is an inner sidewall of the chamber, and wherein the second portion is closer to the gas exhaust port than the first portion.
7. A method of removing particles from a chamber of a plasma processing apparatus, wherein the chamber is connected to a gas exhaust port and a plasma of a processing gas is generated in the chamber to plasma process a substrate to be processed, the method comprising:
positively charging the particles at a first region of the chamber by applying a first negative voltage to a first charging electrode installed in a first portion of an inner wall of the chamber;
drift-transferring the positively charged particles towards a second region of the chamber by applying a second negative voltage to a second charging electrode installed in a second portion of the inner wall of the chamber;
guiding the drift-transferred positively charged particles towards the gas exhaust port along the inner wall of the chamber; and
discharging the guided positively charged particles from the chamber through the gas exhaust port,
wherein an absolute value of the second negative voltage is greater than that of the first negative voltage, and
wherein the first portion is an inner ceiling wall of the chamber and the second portion is an inner sidewall of the chamber,
wherein the positively charged particles are generated by colliding particles with positive ions attracted to the first charging electrode, and wherein the second portion is closer to the gas exhaust port than the first portion.
8. The method of claim 1, wherein said positively charging the particles, said drift-transferring the positively charged particles, said guiding the positively charged particles and said discharging the positively charged particles are performed during plasma processing.
9. The method of claim 5, wherein said positively charging the particles, said guiding the positively charged particles and said discharging the positively charged particles are performed during plasma processing.
10. The method of claim 6, wherein said positively charging the particles, said drift-transferring the positively charged particles, said guiding the positively charged particles and said discharging the positively charged particles are performed during plasma processing.
11. The method of claim 7, wherein said positively charging the particles, said drift-transferring the positively charged particles, said guiding the positively charged particles and said discharging the positively charged particles are performed during plasma processing.
12. The method of claim 1, wherein the first charging electrode is attached to a substantial entirety of an inner ceiling wall of the chamber.
13. The method of claim 6, wherein the first charging electrode is attached to a substantial entirety of the inner ceiling wall of the chamber.
14. The method of claim 7, wherein the first charging electrode is attached to a substantial entirety of the inner ceiling wall of the chamber.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An emission current adjusting method for an optical disk device, which is irradiated with a laser beam to perform recording and reproduction of data, the laser beam is driven by emission currents including a current for generating a peak level emission intensity; a current for generating a minimum bottom level emission intensity; and a current for generating an erase level emission intensity between the peak and bottom levels, the emission current adjusting method comprising the steps of:
obtaining an ideal value of an erase current after recording is started;
measuring an erase current after recording is started; and
determining an emission current after recording is started based on,
wherein a bottom current is defined as the current which generates the minimum bottom level emission intensity, an erase current is defined by subtracting the bottom current from the current which generates the erase level emission intensity, and a peak current is defined by subtracting the erase current from the current which generates the peak level emission intensity.
2. The emission current adjusting method as claimed in claim 1, wherein a bottom current after recording is started is determined based on the measured value and the ideal value of the erase current after recording is started.
3. The emission current adjusting method as claimed in claim 1, wherein a bottom current adjustment value after recording is started is determined based on a measured value and an ideal value of the erase current after recording is started.
4. The emission current adjusting method as claimed in claim 3, wherein a value obtained by adding the adjustment value to a bottom current at starting of recording is set as a bottom current after recording is started, and the erase current ideal value is set as an erase current after recording is started.
5. The emission current adjusting method as claimed in claim 4, wherein the ideal value of the erase current is obtained by multiplying a ratio of an erase current to a peak current at starting of recording by a peak current after recording is started.
6. The emission current adjusting method as claimed in claim 4, wherein the erase current ideal value is obtained by multiplying a ratio of erase power to peak power calculated from target peak power and target erase power set before starting recording by a peak current after starting recording.
7. The emission current adjusting method as claimed in claim 1, wherein the ideal value of the erase current is obtained by multiplying a ratio of an erase current to a peak current at starting of recording by a peak current after recording is started.
8. The emission current adjusting method as claimed in claim 1, wherein the erase current ideal value is obtained by multiplying a ratio of erase power to peak power calculated from target peak power and target erase power set before starting recording by a peak current after starting recording.
9. An optical disk device, comprising:
a sample hold circuit which generates an emission intensity waveform by emission currents including a current for generating a peak level emission intensity, a current for generating a minimum bottom level emission intensity; and a current for generating an erase level emission intensity between the peak and bottom levels, and detects at least an erase level by sampling the emission intensity waveform;
a power control part which calculates an adjustment value of a bottom current after recording is started from a measured value and an ideal value of the erase current after recording is started, and calculates a set value of the bottom current on the basis of the adjustment value; and
a laser driver for generating an emission current on the basis of the set value of the bottom current,
wherein a bottom current is defined as the current which generates the minimum bottom level emission intensity, an erase current is defined by subtracting the bottom current from the current which generates the erase level emission intensity, and a peak current is defined by subtracting the erase current from the current which generates the peak level emission intensity.
10. The optical disk device as claimed in claim 9, wherein the laser driver comprises a bottom current generating digital-to-analog converter, an erase current generating digital-to-analog converter, and a peak current generating digital-to-analog converter, and
emission currents are generated by the respective converters on the basis of the set value of the bottom current determined on the basis of the bottom current adjustment value after recording is started, that is calculated from a measured value and an ideal value of the erase current after recording is started.
11. An optical disk device, comprising:
a sample hold circuit which generates an emission intensity waveform by emission currents including a current for generating a peak level emission intensity, a current for generating a minimum bottom level emission intensity; and a current for generating an erase level emission intensity between the peak and bottom levels, and detects at least an erase level by sampling the emission intensity waveform;
a power control part which calculates an adjustment value of a bottom current after recording is started from a measured value and an ideal value of the erase current after recording is started, and calculates a set value of the erase current on the basis of the adjustment value; and
a laser driver for generating an emission current on the basis of the set value of the erase current,
wherein a bottom current is defined as the current which generates the minimum bottom level emission intensity, an erase current is defined by subtracting the bottom current from the current which generates the erase level emission intensity, and a peak current is defined by subtracting the erase current from the current which generates the peak level emission intensity.
12. The optical disk device as claimed in claim 11, wherein the laser driver comprises a bottom current generating digital-to-analog converter, an erase current generating digital-to-analog converter, and a peak current generating digital-to-analog converter, and
emission currents are generated by the respective converters on the basis of the set value of the erase current determined on the basis of the bottom current adjustment value after recording is started, that is calculated from a measured value and an ideal value of the erase current after recording is started.
13. An optical disk device, comprising:
a sample hold circuit which generates an emission intensity waveform by emission currents including a current for generating a peak level emission intensity, a current for generating a minimum bottom level emission intensity; and a current for generating an erase level emission intensity between the peak and bottom levels, and detects at least an erase level by sampling the emission intensity waveform;
a power control part which calculates an adjustment value of a bottom current after recording is started from a measured value and an ideal value of the erase current after recording is started, and calculates a set value of the peak current on the basis of the adjustment value; and
a laser driver for generating an emission current on the basis of the set value of the peak current,
wherein a bottom current is defined as the current which generates the minimum bottom level emission intensity, an erase current is defined by subtracting the bottom current from the current which generates the erase level emission intensity, and a peak current is defined by subtracting the erase current from the current which generates the peak level emission intensity.
14. The optical disk device as claimed in claim 13, wherein the laser driver comprises a bottom current generating digital-to-analog converter, an erase current generating digital-to-analog converter, and a peak current generating digital-to-analog converter, and
emission currents are generated by the respective converters on the basis of the set value of the peak current determined on the basis of the bottom current adjustment value after recording is started, that is calculated from a measured value and an ideal value of the erase current after recording is started.