Substrate transport apparatus

1. A transfer apparatus comprising:

a frame forming a sealed chamber having a chamber atmosphere;

multiple arms connected to the frame and disposed within the sealed chamber, each arm having at least one separate and different end effector, at a distal end of each arm, for supporting a substrate thereon and an independent drive motor for independently extending and retracting the at least one separate and different end effector of the respective arm;

a first drive section disposed outside the sealed chamber and connected to the multiple arms for moving the multiple arms about a common axis; and

a second drive section disposed inside the sealed chamber, the second drive section including a sealed housing configured to hold a sealed atmosphere different than the chamber atmosphere;

wherein the sealed housing has a first sealed portion including a first drive motor that independently effects a first degree of freedom of motion for at least one arm of the multiple arms and a second sealed portion in sealed communication with the first sealed portion and including a second drive motor that independently effects a second degree of freedom of motion for the at least one arm of the multiple arms.

2. The transfer apparatus of claim 1 , wherein at least one of the multiple arms includes another degree of freedom of motion independent of the drive motor for extending and retracting the at least one separate and different end effector of the respective arm.

3. The transfer apparatus of claim 2 , wherein the another degree of freedom of motion effects automatic workpiece centering.

4. The transfer apparatus of claim 2 , wherein the another degree of freedom of motion effects independent workpiece placement adjustment for workpiece holding station location variations.

5. The transfer apparatus of claim 1 , wherein the sealed housing includes an opening in the sealed housing through which the second sealed portion communicates with the first sealed portion.

6. The transfer apparatus of claim 1 , wherein at least one of the first and second degree of freedom of motion is angled with respect to an axis of extension and retraction of a respective arm.

7. The transfer apparatus of claim 1 , wherein at least one of the first and second degree of freedom of motion is coplanar with a seating plane of the end effector.

8. The transfer apparatus of claim 1 , wherein at least one of the first and second degree of freedom of motion is angled with respect to other independent degrees of freedom.

9. The transfer apparatus of claim 1 , wherein at least one of the first and second degree of freedom of motion is parallel with respect to other independent degrees of freedom.

10. The transfer apparatus of claim 1 , wherein the first drive section includes a common rotational drive motor configured to rotate the multiple arms in unison about a common axis of rotation.

11. The transfer apparatus of claim 1 , wherein the multiple arms are telescoping arms.

12. A transfer apparatus comprising:

a frame forming a sealed chamber having a chamber atmosphere;

multiple arms connected to the frame and disposed within the sealed chamber, each arm having at least one separate and different substrate holder at a distal end of each arm and an independent drive motor for independently extending and retracting the at least one separate and different substrate holder of the respective arm;

a first drive section disposed outside the sealed chamber and connected to the multiple arms for moving the multiple arms about a common axis; and

a second drive section disposed inside the sealed chamber and having

a first sealed portion including a first drive motor that independently effects a first degree of freedom of motion for at least one arm of the multiple arms, and

a second sealed portion in sealed communication with the first sealed portion and including a second drive motor that independently effects a second degree of freedom of motion of at least another arm of the multiple arms, the second sealed portion being movably coupled to the first sealed portion by a movable coupling so as to change a spatial relationship of the second degree of freedom of motion relative to the first degree of freedom of motion.

13. The transfer apparatus of claim 12 , wherein the movable coupling is independent of the drive motor for extending and retracting the respective at least one separate and different substrate holder of the multiple arms.

14. The transfer apparatus of claim 13 , wherein the movable coupling effects automatic workpiece centering.

15. The transfer apparatus of claim 13 , wherein the movable coupling effects independent workpiece placement adjustment for workpiece holding station location variations.

16. The transfer apparatus of claim 12 , wherein the sealed housing includes an opening in the sealed housing through which the second sealed portion communicates with the first sealed portion.

17. The transfer apparatus of claim 12 , wherein at least one of the first degree of freedom and the second degree of freedom of motion is angled with respect to an axis of extension and retraction of a respective arm.

18. The transfer apparatus of claim 12 , wherein at least one of the first degree of freedom and the second degree of freedom of motion is coplanar with a seating plane of the at least one separate and different substrate holder.

19. The transfer apparatus of claim 12 , wherein at least one of the first degree of freedom of motion and the second degree of freedom of motion is angled with respect to other independent degrees of freedom of the transfer apparatus.

20. The transfer apparatus of claim 12 , wherein at least one of the first and second degree of freedom of motion is parallel with respect to other independent degrees of freedom of motion.