Semiconductor laser diode and method for manufacturing the same

A semiconductor laser diode assembly comprising:

• a semiconductor laser diode and a submount to which the semiconductor laser diode is flip-chip bonded,
• the semiconductor laser diode including:
• a first material layer, an active layer, and a second material layer that are sequentially formed on a substrate;
• a ridge portion and a protrusion portion that are formed on the second material layer in a direction perpendicular to the active layer, the protrusion portion being formed at one side of the ridge portion;
• a second electrode layer formed in contact with a top surface of the ridge portion;
• a current restricting layer formed on an entire surface of the second material layer and exposing the second electrode layer;
• a protective layer formed only on a surface of the current restricting layer above the protrusion portion and having an etch selectivity different from that of the current restricting layer;
• a bonding metal layer formed on the current restricting layer and the protective layer in electrical connection with the second electrode layer;
• and
• a first electrode layer formed on an exposed surface of the first material layer, the exposed surface being formed at the other side of the ridge portion, the submount including:
• a first solder layer bonded to the first electrode layer;
• and
• a second solder layer bonded to the bonding metal layer above the ridge portion and the protrusion portion.

A semiconductor laser diode assembly comprising:

• a semiconductor laser diode and a submount to which the semiconductor laser diode is flip-chip bonded,
• the semiconductor laser diode including:
• a first material layer, an active layer, and a second material layer that are sequentially formed on a substrate;
• a ridge portion and a first protrusion portion that are formed on the second material layer in a direction perpendicular to the active layer, the first protrusion portion being formed at one side of the ridge portion;
• a second protrusion formed at the other side of the ridge portion and separated from the ridge portion by a trench defined therebetween to expose the first material layer;
• a second electrode layer formed in contact with a top surface of the ridge portion;
• a current restricting layer formed on an entire surface of the second material layer and exposing the second electrode layer;
• a protective layer formed only on a surface of the current restricting layer above the first protrusion portion and having an etch selectivity different from that of the current restricting layer;
• a bonding metal layer formed on the current restricting layer and the protective layer in electrical connection with the second electrode layer;
• and
• a first electrode layer formed on the current restricting layer above the second protrusion portion in electrical connection with the exposed surface of the first material layer,
• the submount including:
• a first solder layer bonded to the first electrode layer located above the second protrusion;
• and
• a second solder layer bonded to the bonding metal layer located above the ridge portion and the first protrusion portion.

A method for manufacturing a semiconductor laser diode, comprising:

• sequentially forming a first material layer, an active layer, a second material layer, and an electrode layer on a substrate;
• forming a ridge portion and a protrusion portion on upper portions of the second material layer by sequentially etching the electrode layer and the second material layer;
• forming a current restricting layer to cover the second material layer and the electrode layer;
• forming a protective layer only on the current restricting layer above the protrusion portion, the protective layer being formed of material having an etch selectivity different from that of the current restricting layer;
• exposing the protective layer and the electrode layer formed on the ridge portion through planarization;
• and
• forming a bonding metal layer on the current restricting layer to cover the electrode layer and the protective layer.

A method for manufacturing a semiconductor laser diode, comprising:

• sequentially forming a first material layer, an active layer, and a second material layer on a substrate;
• forming a ridge portion and a first protrusion portion on the second material layer in a direction perpendicular to the active layer, the first protrusion portion being formed at one side of the ridge portion;
• forming a second electrode layer in contact with a top surface of the ridge portion;
• forming a current restricting layer on an entire surface of the second material layer and exposing the second electrode layer;
• forming a protective layer only on a surface of the current restricting layer above the first protrusion portion and having an etch selectivity different from that of the current restricting layer;
• and
• forming a bonding metal layer on the current restricting layer and the protective layer in electrical connection with the second electrode layer.