END EFFECTOR TO SUBSTRATE OFFSET DETECTION AND CORRECTION

1 . A port door providing an interface into a processing tool, comprising:

first and second arms pivotably mounted on a top edge of the port door, the first and second arms configured to extend from a plane of the port door towards a carrier containing substrates for the processing tool, the first arm having an emitter transmitting a beam that is split into a plurality of sub-beams within the first arm, the second arm having a plurality of sensors receiving corresponding sub-beams, wherein one of sub-beams provides information as to a position of an end effector relative to a gap between the substrates in the carrier.

2 . The port door of claim 1 , wherein the port door moves in a plane normal to a processing surface of the substrates.

3 . The port door of claim 1 , wherein the first arm includes a plurality of semi-transparent mirrors along a travel path of the beam, the semi-transparent mirrors directing a portion of the beam to a corresponding sensor and a remaining portion of the beam to another semi-transparent mirror.

4 . The port door of claim 1 , wherein the first arm splits the beam into 3 sub-beams, the three sub-beams.

5 . The port door of claim 4 , wherein a first sub-beam detects a position of an end effector, a second sub-beam detects whether a substrate is protruding out of the carrier, and a third sub-beam detects positions of top and bottom surfaces of the substrates.

6 . The port door of claim 1 , wherein the first arm includes a plurality of sensors configured to detect a reflection of the sub-beams from the second arm.

7 . A port door of a processing tool for interfacing with a substrate carrier, comprising:

a planar surface having a top edge;

first and second extensions pivotably mounted on the top edge, the first and second extensions configured to pivot towards the substrate carrier;

an emitter transmitting a beam along a length of the first extension;

a plurality of splitters serially disposed along the length of the first extension, each of the plurality of splitters redirecting a portion of the beam towards the second extension, wherein one of the redirected portions provides information as to a position of an end effector relative to a gap between substrates in the substrate carrier.

8 . The port door of claim 7 , wherein the first extension includes sensors configured to detect corresponding redirected portions after being reflected from reflectors disposed in the second extension.

9 . The port door of claim 7 , wherein the port door is integrated into a loadport and is configured to move in a direction substantially parallel to a z axis of the substrate carrier.

10 . The port door of claim 7 , wherein the second extension includes sensors for receiving each of the redirected portions.

11 . The port door of claim 7 , wherein a first redirected portion detects a position of an end effector, a second redirected portion detects whether a substrate is protruding out of the substrate carrier, and a third redirected portion detects positions of top and bottom surfaces of the substrates.

12 . A method for transferring a substrate from a carrier, comprising:

positioning the carrier onto a carrier interface of a processing tool;

transitioning a door of the processing tool to allow transfer of the substrate, the transitioning including,

pivoting a first and a second extension toward the carrier;

generating a beam from an emitter disposed within the first extension;

splitting the beam into multiple sub-beams;

redirecting each sub-beam toward the second extension;

positioning an end effector to transfer a substrate from the carrier;

determining a position of the end effector relative to a position of the substrate through first and second sub-beams; and

adjusting the position of the end effector when the position of the end effector the position of the substrate coincide.

13 . The method of claim 12 , wherein the adjusting includes correcting a tilt of the end effector.

14 . The method of claim 12 , wherein the adjusting includes adjusting a vertical height of the end effector relative to the substrate.

15 . The method of claim 12 , further comprising;

moving the door of the processing tool substantially parallel to a vertical axis of the substrate carrier.

16 . The method of claim 15 , wherein the positioning the end effector occurs contemporaneously with moving the door of the processing tool.

17 . The method of claim 12 , wherein the transitioning includes,

reflecting each sub-beam to the first extension.

18 . The method of claim 12 , wherein the multiple sub-beams include a first sub-beam and a second sub-beam, the first sub-beam detects positions of a top and a bottom surface of the end effector along an axis substantially parallel to a vertical axis of the substrate carrier.

19 . The method of claim 18 , wherein the second sub-beam detects positions of a top and a bottom surface of the substrate along the axis.