Plasma processing apparatus, plasma processing method and plasma processing analysis method

A plasma processing apparatus which performs plasma processing on a specimen with Advanced Process Control (APC) in use as control to suppress fluctuations in plasma processing by feedback control or feedforward control, the apparatus comprising:

• an analysis unit configured to select a combination for the APC of plasma emission wavelength, time interval for the plasma emission wavelength, and a parameter for the plasma processing,
• wherein the analysis unit is configured to
• obtain a first regression equation representing correlation between a plasma emission intensity and a plasma processing result from temporal change data of the plasma processing according to a fixed recipe;
• obtain a second regression equation representing correlation between the plasma emission intensity and the plasma processing result according to a changed recipe based on experimental data;
• and
• select the combination for the APC of plasma emission wavelength, time interval for the plasma emission wavelength, and a parameter for the plasma processing so as to
• make a coefficient of correlation of the first regression equation higher than a first prescribed value;
• and
• make a difference between a gradient of the first regression equation and the gradient of the second regression equation smaller than a second prescribed value.

A plasma processing apparatus which performs plasma processing on a specimen with Advanced Process Control (APC) in use as control to suppress fluctuations in plasma processing by feedback control or feedforward control and is connected to an analysis unit configured to select a combination for the APC of plasma emission wavelength, time interval for the plasma emission wavelength, and a parameter for the plasma processing, the apparatus comprising:

• the analysis unit further configured to
• obtain a first regression equation representing correlation between a plasma emission intensity and a plasma processing result from temporal change data of the plasma processing according to a fixed recipe;
• obtain a second regression equation representing correlation between the plasma emission intensity and plasma processing result according to a changed recipe based on experimental data;
• select the combination for the APC of plasma emission wavelength, time interval for the plasma emission wavelength, and a parameter for the plasma processing so as to
• make a coefficient of correlation of the first regression equation higher than a first prescribed value;
• and
• make a difference between a gradient of the first regression equation and the gradient of the second regression equation smaller than a second prescribed value.

An analysis unit comprising:

• the analysis unit configured to select a combination of plasma emission wavelength, time interval for the plasma emission wavelength, and a parameter for plasma processing to suppress fluctuations under control in the plasma processing by feedback control or feedforward control,
• wherein a first regression equation representing correlation between a plasma emission intensity and a plasma processing result is obtained from temporal change data of the plasma processing according to a fixed recipe,
• wherein a second regression equation representing a correlation between the plasma emission intensity and plasma processing result is obtained according to a changed recipe based on experimental data, and
• wherein the combination of plasma emission wavelength, time interval for the plasma emission wavelength, and a parameter for plasma processing is selected so as to
• make a coefficient of correlation of the first regression equation higher than a first prescribed value;
• and
• make a difference between a gradient of the first regression equation and the gradient of the second regression equation smaller than a second prescribed value.

A plasma processing method using a plasma processing apparatus which performs plasma processing on a specimen with Advanced Process Control (APC) in use as control to suppress fluctuations in plasma processing by feedback control or feedforward control and comprises an analysis unit to find a combination for the APC of plasma emission wavelength, time interval for the plasma emission wavelength, and a parameter for the plasma processing, the method comprising the steps of:

• obtaining a first regression equation representing correlation between a plasma emission intensity and a plasma processing result from temporal change data of the plasma processing according to a fixed recipe;
• obtaining a second regression equation representing correlation between the plasma emission intensity and plasma processing result according to a changed recipe based on experimental data;
• and
• selecting the combination for the APC of plasma emission wavelength, time interval for the plasma emission wavelength, and a parameter for the plasma processing so as to
• make a coefficient of correlation of the first regression equation higher than a first prescribed value;
• and
• make a difference between a gradient of the first regression equation and the gradient of the second regression equation smaller than a second prescribed value.

An analysis method comprising:

• finding a combination of plasma emission wavelength, time interval for the plasma emission wavelength, and a parameter for plasma processing to suppress fluctuations under control in the plasma processing by feedback control or feedforward control,
• wherein a first regression equation representing a correlation between a plasma emission intensity and a plasma processing result is obtained from temporal change data of the plasma processing according to a fixed recipe,
• wherein a second regression equation representing correlation between the plasma emission intensity and plasma processing result is obtained according to a changed recipe based on experimental data, and
• wherein the combination of plasma emission wavelength, time interval for the plasma emission wavelength, and a parameter for plasma processing is selected so as to
• make a coefficient of correlation of the first regression equation higher than a first prescribed value;
• and
• make a difference between a gradient of the first regression equation and the gradient of the second regression equation smaller than a second prescribed value.