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US 5,472,550 AGranted
Method and apparatus for protecting a substrate surface from contamination using the photophoretic effect
AssigneeResearch Triangle Institute
InventorRavindran Periasamy
Life of this patent
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Abstract
An apparatus for processing a substrate surface in a process chamber wherein during chemical or physical altering of the substrate surface a laser beam is projected inside the processing chamber and along a trajectory which does not contact the substrate surface in order to capture particles by means of the photophoretic effect, particles which would otherwise impinge upon and contaminate the substrate surface.
Claims24
An apparatus for processing a substrate surface of a substrate, comprising:
- a process chamber;
- means for processing the substrate surface by chemically or physically altering the substrate surface;
- a substrate fixture for holding the substrate in the processing chamber so that the substrate surface is exposed to the inside of the processing chamber;
- means for inhibiting contamination of the substrate surface by particles, comprising:
- (a) means for forming a first laser beam;
- (b) means for forming a second laser beam;
- (c) means for scanning the first laser beam along first scanning trajectories which do not contact the substrate surface, wherein each of the first scanning trajectories has a segment disposed closer to a point on the substrate surface than all opposing structural elements in the processing chamber which are opposed to the substrate surface;
- (d) means for scanning the second laser beam along second scanning trajectories which do not contact the substrate surface, wherein each of the second scanning trajectories has a segment disposed closer to a point on the substrate surface than all opposing structural elements in the processing chamber which are opposed to the substrate surface;
- and
- wherein at least some of the second scanning trajectories and at least some of the first scanning trajectories cross to provide a tent-like cover over the substrate surface;
- wherein a vector that is collinear with any of said first scanning trajectories and which points along the direction of propagation of said first laser beam at a point that opposes the substrate surface has a vector component that is perpendicular to the substrate surface that points away from the substrate surface;
- wherein a vector that is collinear with any of said second scanning trajectories and which points along the direction of propagation of said second laser beam at a point that opposes the substrate surface has a vector component which is perpendicular to the substrate surface that points away from the substrate surface.
9 more elements
An apparatus for processing a substrate surface of a substrate, comprising:.
- a process chamber;
- means for processing the substrate surface by chemically or physically altering the substrate surface;
- a substrate fixture for holding the substrate in the processing chamber so that the substrate surface is exposed to the inside of the processing chamber;
- means for inhibiting contamination of the substrate surface by particles, comprising:
- (a) means for forming a first laser beam,
- (b) means for forming a second laser beam;
- (c) means for fanning out the first laser beam into a first fan shaped laser beam along a first trajectory which does not contact the substrate surface;
- (d) means for fanning out the second laser beam into a second fan shaped laser beam along a second trajectory which does not contact the substrate surface;
- wherein the first fan shaped laser beam and the second fan shaped laser beam cross inside the processing chamber to provide a tent-like cover over the substrate surface such that a vector pointing along any direction of propagation of either the first fan shaped laser beam or the second fan shaped laser beam at a point that opposes the substrate surface has a vector component in a direction that is perpendicular to the substrate surface that points away from the substrate surface.
6 more elements
Dependencies are inferred from the claim text.