Abstract: A substrate transfer system comprises plural end-effectors that are placed so as to touch a periphery of a cone having a vertical angle at a 2&thgr; angle with respect to a central axis at an arbitrary &thgr; angle to a horizontal plane, wherein substrates are interchanged and simultaneously transferred where the end-effectors are in a horizontal position. Besides, since the end-effectors are vertically located, the minimum rotational radius of the system that is projected to a horizontal plane, can be reduced. This contributes toward the reduction of an installation area for a substrate processing equipment in which the substrate transfer system is equipped.

Abstract: A substrate transfer system employs a robot hand which is composed such that a sum length of a first arm and a third arm equal a length of a second arm, and a length of the first arm becomes longer than a length of the third arm. A ratio between arm lengths is determined such that a distal end portion of the first arm, a distal end portion of the second arm, a distal end portion of the third arm, and a distal end portion of the workpiece held by the end effector are inscribed in a track circle around a rotational axis of the first arm as a center. The ratio of the first, second and third arm lengths is approximately 1:({square root over ( )}5+1)/2:({square root over ( )}5−1)/2. This optimized ratio of the arm lengths allows the arm rotational radius to be smaller than the conventional value, and makes it possible to achieve a longer transfer distance in an equal installation area.

Abstract: A substrate transfer system comprises plural end-effectors that are placed so as to touch a periphery of a cone having a vertical angle at a 2&thgr; angle with respect to a central axis at an arbitrary 0 angle to a horizontal plane, wherein substrates are interchanged and simultaneously transferred where the end-effectors are in a horizontal position. Besides, since the end-effectors are vertically located, the minimum rotational radius of the system that is projected to a horizontal plane, can be reduced. This contributes toward the reduction of an installation area for a substrate processing equipment in which the substrate transfer system is equipped.