Method of manufacturing semiconductor optical device

A method of manufacturing a semiconductor optical device having a first substrate and a chip including a III-V compound semiconductor, the method comprising:

• forming a first semiconductor layer on a second substrate;
• forming a second semiconductor layer on the first semiconductor layer;
• forming, on the second substrate, a mesa including a portion of the second semiconductor layer;
• cutting the second substrate to form a chip including the mesa and the second substrate;
• bonding the mesa of the chip to the first substrate;
• after the bonding, removing the second substrate by etching;
• and
• after the removing the second substrate, removing the first semiconductor layer,
• wherein the etching in the removing the second substrate proceeds more easily in a second direction crossing a first direction than in the first direction, and
• after the cutting, a length of the mesa in the first direction is equal to or less than a length of the second substrate in the first direction.