Abstract: It is the object of the present invention to provide a manufacturing method for a compound semiconductor device capable of removing remaining organic substances without deteriorating a characteristic of the compound semiconductor device, wherein a surface of an i-type AlGaAs schottky layer is cleaned in a state where light is blocked using either one of ozonized (O3) water whose ozone concentration is at most 13 mg/L and hydrogenated (H2) water whose hydrogen ion concentration (pH) is from 6 to 8 inclusive, or using both of the ozonized water and the hydrogenated water after a schottky electrode made of Ti/Al/Ti is evaporated onto the exposed i-type AlGaAs schottky layer and a lift-off operation is performed using a remover.

Abstract: It is the object of the present invention to provide a manufacturing method for a compound semiconductor device capable of removing remaining organic substances without deteriorating a characteristic of the compound semiconductor device, wherein a surface of an i-type AlGaAs schottky layer 105 is cleaned in a state where light is blocked using either one of ozone (O3) water whose ozone concentration is 13 mg/L or less and hydrogen (H2) water whose hydrogen ion concentration (pH) is from 6 to 8 inclusive, or using both of the ozone water and the hydrogen water after a schottky electrode 111 made of Ti/Al/Ti is evaporated onto the exposed i-type AlGaAs schottky layer 105 and a lift-off is performed using a remover.

Abstract: The sealing oil in a sealing device for an underwater propeller shaft as maintained at the optimum operating pressure by providing a pressure increasing device in which an oil chamber communicating with the sealing oil and a sea water chamber communicating with the sea water in the vicinity of the propeller shaft are separated by a movable member, e.g., a bellows.