Method and apparatus for displaying process endpoint signal based on emission concentration within a processing chamber

Claim 1

A method for displaying a signal which represents the variation of light intensity over time in a processing chamber comprising the steps of: (a) detecting the light intensity within the process chamber to produce a voltage signal with a voltage amplitude varying with the light intensity within the process chamber; (b) digitally sampling the voltage amplitude of the voltage signal at a sampling interval (I) to obtain sample values (S x ); (c) displaying in a graph sequential values of the voltage signal along a y-axis versus time along an x-axis; (d) superimposing over the graph a rectangular box having a height H representing an amount of light intensity extending in the direction of the y-axis and a width W representing an amount of time extending in the direction of the x-axis that includes earlier displayed voltage signals and placed so that the midpoint of the left side of the rectangular box is coincident with an earlier displayed voltage signal; (e) waiting for one of a positive slope, a negative slope and a zero slope; (f) detecting whether a newly displayed voltage signal exits to the right of the rectangular box, above the rectangular box or below the rectangular box; (g) when the newly displayed discrete value of the voltage signal is at the right of the rectangular box, designating the slope of the graph at the discrete value as having a zero slope; (h) when the newly displayed discrete value of the voltage signal is above the rectangular box, designating the slope of the graph at the discrete value as having a positive slope; (i) when the newly displayed discrete value of the voltage signal is below the rectangular box, designating the slope of the graph at the discrete value as having a negative slope; and (j) highlighting the rectangular box when the slope designated in steps (g), (h) and (i) is the waited for slope of step (e).

Claim 2

A method for displaying a signal which represents the variation of light intensity over time in a processing chamber comprising the steps of: (a) detecting the light intensity within the process chamber to produce a voltage signal with a voltage amplitude varying with the light intensity within the process chamber; (b) digitally sampling the voltage amplitude of the voltage signal at a sampling interval (I) to obtain sample values (S x ); (c) displaying in a graph sequential values of the voltage signal along a y-axis versus time along an x-axis; (d) superimposing over the graph a rectangular box having a height H representing an amount of light intensity extending in the direction of the y-axis and a width W representing an amount of time extending in the direction of the x-axis that includes earlier displayed voltage signals and placed so that the midpoint of the left side of the rectangular box is coincident with an earlier displayed voltage signal; (e) waiting for one of a positive slope, a negative slope and a zero slope; (f) detecting whether a newly displayed voltage signal exits to the right of the rectangular box, above the rectangular box or below the rectangular box; (g) when the newly displayed discrete value of the voltage signal is at the right of the rectangular box, designating the slope of the graph at the discrete value as having a zero slope; (h) when the newly displayed discrete value of the voltage signal is above the rectangular box, designating the slope of the graph at the discrete value as having a positive slope; (i) when the newly displayed discrete value of the voltage signal is below the rectangular box, designating the slope of the graph at the discrete value as having a negative slope; and (j) highlighting the rectangular box when the slope designated in steps (g), (h) and (i) is the waited for slope of step (e).

Claim 5

An apparatus for displaying a signal which represents the variation of light intensity in a processing chamber over time comprising: (a) detecting means, coupled to the processing chamber, for detecting the light intensity within the process chamber to produce a voltage signal with a voltage amplitude varying with the light intensity within the processing chamber; (b) sampling means coupled to the detecting means for digitally sampling the voltage amplitude of the voltage signal at a sampling interval (I) to obtain samples values (S x ); (c) display means for displaying in a graph sequential values of the voltage signal along a y-axis versus time along an x-axis and for highlighting a change in the slope of the graph; and (d) means for changing the processing conditions within said chamber in response to step (c).

Claim 6

An apparatus for displaying a signal which represents the variation of light intensity in a processing chamber over time comprising: (a) detecting means, coupled to the processing chamber, for detecting the light intensity within the process chamber to produce a voltage signal with a voltage amplitude varying with the light intensity within the processing chamber; (b) sampling means coupled to the detecting means for digitally sampling the voltage amplitude of the voltage signal at a sampling interval (I) to obtain samples values (S x ); (c) display means for displaying in a graph sequential values of the voltage signal along a y-axis versus time along an x-axis and for highlighting a change in the slope of the graph; and (d) means for changing the processing conditions within said chamber in response to step (c).

Claim 9

A method for monitoring a process within a reaction chamber comprising (a) detecting light intensity of a plasma in the reaction chamber to produce a voltage signal with a voltage amplitude varying with the light intensity; (b) displaying in a graph sequential values of the voltage signal along a y-axis versus time along an x-axis; (c) superimposing over the graph a rectangular box having a height H representing an amount of light intensity extending in the direction of the y-axis, and a width W representing an amount of time extending in the direction of the x-axis that includes earlier displayed voltage signals and placed so that the midpoint of the left side of the rectangular box is coincident with an earlier displayed voltage signal; (d) programming a computer to monitor and display changes in the slope of the graph; and (e) intervening in said process when an anticipated sequence of one or more slopes has been displayed.

Claim 10

A method for monitoring a process within a reaction chamber comprising (a) detecting light intensity of a plasma in the reaction chamber to produce a voltage signal with a voltage amplitude varying with the light intensity; (b) displaying in a graph sequential values of the voltage signal along a y-axis versus time along an x-axis; (c) superimposing over the graph a rectangular box having a height H representing an amount of light intensity extending in the direction of the y-axis, and a width W representing an amount of time extending in the direction of the x-axis that includes earlier displayed voltage signals and placed so that the midpoint of the left side of the rectangular box is coincident with an earlier displayed voltage signal; (d) programming a computer to monitor and display changes in the slope of the graph; and (e) intervening in said process when an anticipated sequence of one or more slopes has been displayed.

Claim 13

A method for displaying a filtered signal which represents the variation of light intensity over time in a processing chamber wherein a magnetic field generated by a signal with a period T causes plasma to rotate within the processing chamber, comprising the steps of: (a) detecting the light intensity within the process chamber to produce a voltage signal with a voltage amplitude varying with the light intensity within the process chamber; (b) digitally sampling the voltage amplitude of the voltage signal at a sampling interval (I) to obtain sample values (S x ); (c) calculating running averages (R y ) of a preselected number (N) of sample values (S y ); (d) setting the period T equal to the preselected number (N) times the sampling interval (I) times an integer; (e) displaying in a graph sequential values of the voltage signal along a y-axis versus time along an x-axis.

Claim 14

A method for displaying a filtered signal which represents the variation of light intensity over time in a processing chamber wherein a magnetic field generated by a signal with a period T causes plasma to rotate within the processing chamber, comprising the steps of: (a) detecting the light intensity within the process chamber to produce a voltage signal with a voltage amplitude varying with the light intensity within the process chamber; (b) digitally sampling the voltage amplitude of the voltage signal at a sampling interval (I) to obtain sample values (S x ); (c) calculating running averages (R y ) of a preselected number (N) of sample values (S y ); (d) setting the period T equal to the preselected number (N) times the sampling interval (I) times an integer; (e) displaying in a graph sequential values of the voltage signal along a y-axis versus time along an x-axis.