Optical recording medium, manufacturing method thereof, recording material for optical recording medium, and sputtering target for optical recording medium

A manufacturing method of an optical recording medium, comprising:

• forming a recording layer by sputtering a target while introducing a process gas, wherein
• the target contains an oxide of Bi and an oxide of Al,
• a ratio of a first amount of the oxide of Al in the target to a second amount of the oxide of Bi and the oxide of Al in the target is 15 vol % or more and 50 vol % or less,
• the process gas contains a rare gas and oxygen, and
• a flow rate ratio of the oxygen to the rare gas (an oxygen flow rate/a rare gas flow rate) is 0.15 or more.

A recording material for an optical recording medium, containing:

• an oxide of Bi;
• and
• an oxide of Al, wherein
• a ratio of a first amount of the oxide of Al in the recording material to a second amount of the oxide of Bi and the oxide of Al in the recording material is 15 vol % or more and 50 vol % or less.

A sputtering target for an optical recording medium, containing:

• an oxide of Bi;
• and
• an oxide of Al, wherein
• a ratio of a first amount of the oxide of Al in the sputtering target to a second amount of the oxide of Bi and the oxide of Al in the sputtering target is 15 vol % or more and 50 vol % or less.