In situ film growth sensor assembly, apparatus, and methods
Embodiments disclosed herein generally relate to in situ monitoring of film growth in processing chambers. In some examples, a sensor assembly for a processing chamber includes a sensor tube including silicon carbide and having an optical path therein and a sensor window including crystalline silicon carbide and having a proximal side coupled to a distal end of the sensor tube. The sensor window covers the optical path, and a distal side of the sensor window facing away from the proximal side is perpendicular to a center axis of the optical path.
1 . A processing chamber suitable for use in semiconductor manufacturing, comprising:
a susceptor; and
a sensor assembly, comprising:
a sensor tube comprising silicon carbide and having an optical path therein, the sensor tube disposed through a body of a pre-heat ring disposed outwardly of the susceptor;
a sensor window comprising crystalline silicon carbide and having a proximal side coupled to a distal end of the sensor tube, wherein the sensor window covers the optical path, and wherein a distal side of the sensor window facing away from the proximal side is perpendicular to a center axis of the optical path;
a sleeve disposed around a proximal end of the sensor tube, the sleeve comprising a vent formed in a wall of the sleeve, the vent including an opening extending from an outer surface of the wall and to an inner surface of the wall; and
one or more fiber optic cables disposed in tubing, the one or more fiber optic cables operable to transmit light.
2 . The processing chamber of claim 1 , wherein the sensor tube comprises sintered silicon carbide.
3 . The processing chamber of claim 1 , wherein the crystalline silicon carbide of the sensor window comprises at least one of a 6H, 4H, or 3C crystalline structure.
4 . The processing chamber of claim 1 , wherein the sleeve comprises at least one of silicon carbide, black quartz, or opaque quartz.
5 . The processing chamber of claim 1 , wherein the sensor tube and the sleeve are movable relative to each other in a direction parallel to the center axis of the optical path.
6 . The processing chamber of claim 5 , further comprising a radial gap disposed between overlapping portions of the sensor tube and sleeve.
7 . The processing chamber of claim 1 , wherein a joint couples the sensor window to the sensor tube, and the joint has a filler material.
8 . The processing chamber of claim 7 , wherein the filler material comprises silicon carbide.
9 . The processing chamber of claim 1 , wherein the vent includes an opening formed below the proximal end of the sensor tube.
10 . The processing chamber of claim 1 , wherein:
the sensor tube extends into a distal end of the sleeve; and
the one or more fiber optic cables are positioned at a spacing from the sleeve.
11 . The processing chamber of claim 1 , wherein the one or more fiber optic cables are disposed outside of the sensor tube and the sleeve.
12 . A processing chamber suitable for use in semiconductor manufacturing, comprising:
a chamber body, comprising:
an upper window, a lower window, and a side wall defining a processing region;
a process gas inlet formed through the side wall;
a susceptor disposed in the processing region and having a substrate-receiving top surface;
a pre-heat ring surrounding the susceptor;
a rotatable shaft supporting the susceptor; and
a sensor assembly, comprising:
a sensor tube comprising silicon carbide and having an optical path therein, the sensor tube disposed through a body of the pre-heat ring; and
a sensor window comprising crystalline silicon carbide and having a proximal side coupled to a distal end of the sensor tube, wherein the sensor window covers the optical path, and wherein a distal side of the sensor window facing away from the proximal side is perpendicular to a center axis of the optical path;
a sleeve disposed around a proximal end of the sensor tube, the sensor tube extending into a distal end of the sleeve, the sleeve comprising a vent formed in a wall of the sleeve, the vent including an opening extending from an outer surface of the wall and to an inner surface of the wall, and the sleeve and the sensor tube disposed between the lower window and the upper window of the chamber body; and
one or more fiber optic cables disposed in tubing, the one or more fiber optic cables operable to transmit light, and the tubing and the one or more fiber optic cables disposed outside of the lower window.
13 . The processing chamber of claim 12 , wherein a proximal end of the sleeve is coupled to an inside of the lower window.
14 . The processing chamber of claim 12 , wherein the distal side of the sensor window is parallel to a plane of the pre-heat ring.
15 . The processing chamber of claim 12 , wherein the one or more fiber optic cables are optically coupled to the optical path of the sensor tube.
16 . The processing chamber of claim 12 , wherein the sensor tube and the sleeve are movable relative to each other in a direction parallel to the center axis of the optical path.
17 . The processing chamber of claim 16 , further comprising a radial gap disposed between overlapping portions of the sensor tube and sleeve.