Metrology enclosure including spectral reflectometry system for plasma processing system using direct-drive radiofrequency power supply
A plasma processing chamber has an upper window with a coil disposed above the upper window. A coil connection enclosure is disposed above the coil. A metrology enclosure is disposed above the coil connection enclosure. A spectral reflectometry system is disposed within the metrology enclosure. The spectral reflectometry system includes an optical collimator positioned to direct a beam of light through an opening in the metrology enclosure, an opening in the coil connection enclosure, and the upper window into the plasma processing chamber. The optical collimator is also configured to receive reflected light from within the plasma processing chamber, where the reflected light passes through the upper window and through the opening in the coil connection enclosure and through the opening in the metrology enclosure. A tip angle and a tilt angle of the optical collimator are remotely adjusted to optimize an orientation of the optical collimator.
1 . A plasma processing system, comprising:
a plasma processing chamber having an upper window;
a coil disposed above the upper window;
a coil connection enclosure disposed above the coil;
a metrology enclosure disposed above the coil connection enclosure; and
a spectral reflectometry system disposed within the metrology enclosure, the spectral reflectometry system including:
an optical collimator positioned to direct a beam of light through an opening in the metrology enclosure, an opening in the coil connection enclosure, and the upper window into the plasma processing chamber, the optical collimator configured to receive reflected light from within the plasma processing chamber, the reflected light passing through the upper window and through the opening in the coil connection enclosure and through the opening in the metrology enclosure; and
an orientation control stage for the optical collimator, the orientation control stage including a lower member and an upper member, the lower member having an upper surface configured as a portion of a spherical cap, the upper member having a lower surface shaped conformally to the upper surface of the lower member, the upper member movable relative to the lower member.
2 . The plasma processing system as recited in claim 1 , wherein the spectral reflectometry system within the metrology enclosure includes a lamp, a power supply, and a spectrometer.
3 . The plasma processing system as recited in claim 2 , wherein a direct-drive radiofrequency power supply is positioned above the metrology enclosure, the direct-drive radiofrequency power supply connected to transmit radiofrequency power to the coil.
4 . The plasma processing system as recited in claim 1 , the orientation control stage further including a tip adjustment device for controlling a tip angle of the optical collimator within a first vertical reference plane.
5 . The plasma processing system as recited in claim 4 , the orientation control stage further including a tilt adjustment device for controlling a tilt angle of the optical collimator within a second vertical reference plane, the second vertical reference plane perpendicular to the first vertical reference plane.
6 . The plasma processing system as recited in claim 5 , the spectral reflectometry system further including a first adjustment mechanism extending from outside of the metrology enclosure to the tip adjustment device, the first adjustment mechanism configured to provide for manual adjustment of the tip angle of the optical collimator from a first location outside of the metrology enclosure.
7 . The plasma processing system as recited in claim 6 , the spectral reflectometry system further including a second adjustment mechanism extending from outside of the metrology enclosure to the tilt adjustment device, the second adjustment mechanism configured to provide for manual adjustment of the tilt angle of the optical collimator from a second location outside of the metrology enclosure.
8 . The plasma processing system as recited in claim 7 , the first adjustment mechanism including a first rod extending from the first location to a first rotational transfer device configured to translate rotation of the first rod into rotation of a first screw within the tip adjustment device.
9 . The plasma processing system as recited in claim 8 , the second adjustment mechanism including a second rod extending from the second location to a second rotational transfer device configured to translate rotation of the second rod into rotation of a second screw within the tilt adjustment device.
10 . The plasma processing system as recited in claim 9 , the first rotational transfer device including a first gear box.
11 . The plasma processing system as recited in claim 10 , the second rotational transfer device including a second gear box.
12 . The plasma processing system as recited in claim 5 , the spectral reflectometry system further including a first motorized adjustment mechanism connected for control of the tip adjustment device, the first motorized adjustment mechanism configured to provide for remote adjustment of the tip angle of the optical collimator in response to a first electrical control signal.
13 . The plasma processing system as recited in claim 12 , the spectral reflectometry system further including a second motorized adjustment mechanism connected for control of the tilt adjustment device, the second motorized adjustment mechanism configured to provide for remote adjustment of the tilt angle of the optical collimator in response to a second electrical control signal.
14 . The plasma processing system as recited in claim 1 , wherein a position of the orientation control stage relative to the metrology enclosure is remotely adjustable.
15 . The plasma processing system as recited in claim 1 , the upper member movable relative to the lower member to control a tip angle of the optical collimator within a first vertical reference plane.
16 . The plasma processing system as recited in claim 15 , the upper member also movable relative to the lower member to control a tilt angle of the optical collimator within a second vertical reference plane, the second vertical reference plane perpendicular to the first vertical reference plane.
17 . The plasma processing system as recited in claim 16 , the spectral reflectometry system including a first motorized adjustment mechanism connected to provide for positioning of the upper member relative to the lower member to control the tilt angle of the optical collimator within the second vertical reference plane, the first motorized adjustment mechanism operable in response to a first electrical control signal.
18 . The plasma processing system as recited in claim 17 , the spectral reflectometry system further including a second motorized adjustment mechanism connected to provide for positioning of the upper member relative to the lower member to control the tip angle of the optical collimator within the first vertical reference plane, the second motorized adjustment mechanism operable in response to a second electrical control signal.