Abstract: An ultrasonic cleaning method in which ultrasonic cleaning of a contamination attached to a surface of an object to be cleaned is performed by directing toward the object to be cleaned, a cleaning liquid to which ultrasonic waves are applied by alternately focusing first ultrasonic waves having a frequency of 1 to 10 MHz and second ultrasonic waves having a frequency equal to or lower than ½ of that of the first ultrasonic waves. A focus position adjustment device is used to adjust the distance of the focus position relative to the surface of the object to be cleaned, and a moving device is used to movie at least one of the ultrasonic wave generation device and a support base for the object so that the effect of the ultrasonic waves generated by the ultrasonic wave generation device on the surface of the object to be cleaned is uniform.

Abstract: An ultrasonic cleaning apparatus which performs ultrasonic cleaning of a contamination attached to a surface of an object to be cleaned, by using a cleaning liquid to which ultrasonic waves are applied has a cleaning bath pooling the cleaning liquid, a support base on which the object to be cleaned is supported in the cleaning liquid, ultrasonic wave generation device for alternately focusing first ultrasonic waves having a frequency of 1 to 10 MHz and second ultrasonic waves having a frequency equal to or lower than ½ of that of the first ultrasonic waves toward the object to be cleaned, a focus position adjustment device of adjusting the distance between a focus position for the focus and the surface of the object to be cleaned, and moving device of moving at least any one of the ultrasonic wave generation device and the support base so that the effect on the surface of the object to be cleaned of the ultrasonic waves generated by the ultrasonic wave generation device is uniform.

Abstract: A draft chamber is located within a clean room for sequentially immersing and processing carriers such as silicone wafers in a plurality of solution vessels provided in the draft chamber. In the draft chamber, a first air flow moves in a substantially horizontal direction from the front portion of the draft chamber toward the rear portion above the surfaces of solutions contained in chemical solution vessels which generate toxic gasses and a second air flow moves downward from the ceiling of the draft chamber. Thus, the toxic gasses generated from the chemical solution vessels are prevented from leaking into the clean room.