Dual multitran robot arm

A substrate transport apparatus comprising:

• a first upper arm mounted on a support rotatable about an upright axis and extending radially therefrom in opposite directions to left and right ends thereof;
• a second upper arm mounted on the support rotatable about the upright axis and extending radially therefrom to a left end thereof;
• a third upper arm mounted on the support rotatable about the upright axis and extending radially therefrom to a right end thereof;
• first and second end effector means for supporting substrates thereon;
• first and second pairs of forearms, each of said first and second pairs of forearms including a left forearm having a left end pivotally connected to said first and second upper arms at said left ends thereof and a right end pivotally connected to said first and second end effector means, respectively, each of said first and second pairs of forearms including a right forearm having a right end pivotally connected to said first and third upper arms at said right ends thereof and a left end pivotally connected to said first and second end effector means, respectively;
• first drive means for rotating said first upper arm about the upright axis selectively either in the clockwise direction or in the counterclockwise direction;
• second drive means for rotating said second upper arm about the upright axis selectively either in the clockwise direction or in the counterclockwise direction;
• third drive means for rotating said third upper arm about the upright axis selectively either in the clockwise direction or in the counterclockwise direction;
• whereby operation of said first and second drive means in the counterclockwise direction and of said third drive means in the clockwise direction causes said first end effector means to move from a retracted position to an extended position and said second end effector means to move from an extended position to a retracted position;
• whereby operation of said first drive means in the clockwise direction and of said second and third drive means in the counterclockwise direction causes said second end effector to move from a retracted position to an extended position and said first end effector means to move from an extended position to a retracted position;
• whereby operation of said first, second, and third drive means in unison in the clockwise direction causes said first, second, and third upper arms to rotate in the clockwise direction;
• and
• whereby operation of said first, second, and third drive means in unison in the counterclockwise direction causes said first, second, and third upper arms to rotate in the counterclockwise direction.

A method of transporting substrates into and out of processing chambers in a substrate processing apparatus, the method comprising the steps of:

• (a) mounting first, second, and third drive arms of a movable arm assembly for independent rotation about a common axis;
• (b) providing a first pair of end effectors on a first side of the movable arm assembly;
• (c) providing a second pair of end effectors on a second side of the movable arm assembly opposite the first side, the end effectors being independently movable along a common path between retracted and extended positions;
• (d) rotating the first, second, and third drive arms about the common axis;
• and
• (e) moving the end effectors along the common path between their respective retracted and extended positions as the first, second, and third drive arms are moved as a result of step (d).