| CPC H01L 21/68 (2013.01) [G01S 15/08 (2013.01); G01S 15/88 (2013.01); H01L 21/67196 (2013.01); H01L 21/67706 (2013.01); H01L 21/6773 (2013.01); H01L 21/67745 (2013.01); H01L 21/67766 (2013.01)] | 12 Claims |
|
1. A substrate transport apparatus comprising:
a support configured to support a substrate;
a moving mechanism configured to move the support in a lateral direction in order to transport the substrate from a first placement portion to a second placement portion, each of the first placement portion and the second placement portion being configured to place thereon the substrate; and
an ultrasonic sensor provided on the support, configured to detect the substrate placed on the first placement portion, configured to emit ultrasonic waves upward, and configured to detect a distance to the substrate placed on the first placement portion,
wherein the support is further configured to be moved by the moving mechanism such that the ultrasonic waves are emitted to different positions on the substrate placed on the first placement portion,
wherein the substrate transport apparatus further comprises: a transport determinator configured to determine whether or not to transport the substrate from the first placement portion based on the distance detected from each of the positions at which the ultrasonic waves are emitted by the ultrasonic sensor,
wherein the moving mechanism operates such that, in a state in which the ultrasonic waves have been emitted from the ultrasonic sensor, a first step is performed, wherein the first step is detecting the distance by the ultrasonic sensor while moving the support from a transport region outside the substrate to a position that is located below the substrate and overlaps the substrate in a plan view,
wherein the transport determinator is further configured to determine whether or not to transport the substrate from the first placement portion based on the distance detected in the first step,
wherein, when a moving direction of the support in the first step is forward, the ultrasonic sensor includes a first ultrasonic sensor and a second ultrasonic sensor which are provided on a left side and a right side of the support, respectively,
wherein the transport determinator is further configured to acquire a position of a center of the substrate based on a peripheral end position of the substrate detected in the first step,
wherein, among a step in which the support is moved such that the first ultrasonic sensor moves along a first arc forming a left side of a circle centered on the center of the substrate in a plan view so that a distance to a peripheral edge portion of the substrate is acquired by the first ultrasonic sensor, and a step in which the support is moved such that the second ultrasonic sensor moves along a second arc forming a right side of the circle so that a distance to the peripheral edge portion of the substrate is acquired by the second ultrasonic sensor, one step is performed as a second step and the other step is performed as a third step following the second step, and
wherein the transport determinator is further configured to determine whether or not to transport the substrate from the first placement portion based on the distances acquired in the second step and the third step.
|