Optical semiconductor device and method for manufacturing the same

• Main Authors: Nishikawa, Satoshi, Akiyama, Koichi, Fukunaga, Keigo, Hokama, Yohei, Suzuki, Yosuke, Horiguchi, Yuichiro
• Format: Patent
• Language: English
• Published: 16.11.2021
• Subjects: DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; PERFORMING OPERATIONS; PHYSICS; PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCESIN A PLASTIC STATE; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

An optical semiconductor device includes a semiconductor substrate, a first semiconductor layer provided on the semiconductor substrate, and a mesa waveguide provided on the principal surface of the first semiconductor layer. The semiconductor device also includes a buried layer covering the upper surface of the first semiconductor layer. Part of the upper surface of the first semiconductor layer is exposed. A mesa structure provided at the boundary between a part of the first semiconductor layer is covered with the buried layer and a part of the first semiconductor layer is exposed. One side of the mesa structure is covered with the buried layer, and the other side is exposed. The optical semiconductor device can reduce the generation of stress in the buried layer, for example, to suppress the occurrence of cracks in the buried layer and enhance the reliability.