Method and apparatus for detecting optimal endpoints in plasma etch processes

An apparatus for detecting an endpoint for terminating a process, comprising:

• means for defining the endpoint in the form of a mode, a minimum value of a delay count, and a threshold;
• means for producing a set of samples;
• means for processing the samples;
• means for incrementing the delay count when the threshold has been exceeded by a predefined number and the mode is met, otherwise setting the delay count equal to zero;
• means for repeating said processing step for each set of samples until the delay count reaches or exceeds the minimum value;
• and
• means for terminating the process when the delay count reaches or exceeds the minimum value.

A method of detecting an endpoint for terminating a process, said method comprising the steps of:

• defining the endpoint in the form of a mode, a minimum value of a delay count, and a threshold;
• producing a set of samples;
• processing the samples;
• determining a first parameter associated with an immediately preceding sample set;
• determining a second parameter associated with a current sample set;
• incrementing the delay count when the threshold has been exceeded by a predefined number and the mode is met, otherwise setting the delay count equal to zero, wherein the mode is met when the first parameter is less than the second parameter;
• repeating said processing step for each set of samples until the delay count reaches or exceeds the minimum value;
• and
• terminating the process when the delay count reaches or exceeds the minimum value.

A method of detecting an endpoint for terminating a process, said method comprising the steps of:

• defining the endpoint in the form of a mode, a minimum value of a delay count, and a threshold;
• producing a set of samples;
• processing the samples;
• determining a first parameter associated with an immediately preceding sample set;
• determining a second parameter associated with a current sample set;
• incrementing the delay count when the threshold has been exceeded by a predefined number and the mode is met, otherwise setting the delay count equal to zero, wherein the mode is met when the first parameter is greater than the second parameter;
• repeating said processing step for each set of samples until the delay count reaches or exceeds the minimum value;
• and
• terminating the process when the delay count reaches or exceeds the minimum value.

A method of detecting an endpoint for terminating a process, said method comprising the steps of:

• defining the endpoint in the form of a mode, a minimum value of a delay count, and a threshold;
• producing a set of samples;
• processing the samples;
• determining a first parameter associated with an immediately preceding sample set;
• determining a second parameter associated with a current sample set;
• incrementing the delay count when the threshold has been exceeded by a predefined number and the mode is met, otherwise setting the delay count equal to zero, wherein the mode is met when the first parameter is less than the threshold and is less than the second parameter;
• repeating said processing step for each set of samples until the delay count reaches or exceeds the minimum value;
• and
• terminating the process when the delay count reaches or exceeds the minimum value.

An apparatus for detecting an endpoint for terminating a process, comprising:

• means for defining the endpoint in the form of a mode, a minimum value of a delay count, and a threshold;
• means for producing a set of samples;
• means for processing the samples;
• means for determining a first parameter associated with an immediately preceding sample set;
• means for determining a second paragraph associated with a current sample set;
• means for incrementing the delay count when the threshold has been exceeded by a predefined number and the mode is met, otherwise setting the delay count equal to zero, wherein the mode is met when the first parameter is less than the second parameter;
• means for repeating said processing step for each set of samples until the delay count reaches or exceeds the minimum value;
• and
• means for terminating the process when the delay count reaches or exceeds the minimum value.

An apparatus for detecting an endpoint for terminating a process, comprising:

• means for defining the endpoint in the form of a mode, a minimum value of a delay count, and a threshold;
• means for producing a set of samples;
• means for processing the samples;
• means for determining a first parameter associated with an immediately preceding sample set;
• means for determining a second paragraph associated with a current sample set;
• means for incrementing a delay count when the threshold has been exceeded by a predefined number and the mode is met, otherwise setting the delay count equal to zero, wherein the mode is met when the first parameter is greater than the second parameter;
• means for repeating said processing step for each set of samples until the delay count reaches or exceeds the minimum value;
• and
• means for terminating the process when the delay count reaches or exceeds the minimum value.

An apparatus for detecting an endpoint for terminating a process, comprising:

• means for defining the endpoint in the form of a mode, a minimum value of a delay count, and a threshold;
• means for producing a set of samples;
• means for processing the samples;
• means for determining a first parameter associated with an immediately preceding sample set;
• means for determining a second paragraph associated with a current sample set;
• means for incrementing the delay count when the threshold has been exceeded by a predefined number and the mode is met, otherwise setting the delay count equal to zero, wherein the mode is met when the first parameter is less than the threshold and less than the second parameter;
• means for repeating said processing step for each step of samples until the delay count reaches or exceeds the minimum value;
• and
• means for terminating the process when the delay count reaches or exceeds the minimum value.