US 11,817,674 B2
Semiconductor optical device and method for manufacturing the same
Ryosuke Nakajima, Kanagawa (JP); Yasushi Sakuma, Tokyo (JP); and Shigetaka Hamada, Kanagawa (JP)
Assigned to Lumentum Japan, Inc., Kanagawa (JP)
Filed by Lumentum Japan, Inc., Kanagawa (JP)
Filed on Dec. 7, 2020, as Appl. No. 17/247,317.
Claims priority of application No. 2020-109389 (JP), filed on Jun. 25, 2020; and application No. 2020-139167 (JP), filed on Aug. 20, 2020.
Prior Publication US 2021/0408760 A1, Dec. 30, 2021
Int. Cl. H01S 5/028 (2006.01); H01S 5/042 (2006.01); H01S 5/22 (2006.01); H01S 5/34 (2006.01); G02F 1/017 (2006.01)
CPC H01S 5/04256 (2019.08) [H01S 5/0282 (2013.01); H01S 5/22 (2013.01); G02F 1/017 (2013.01); G02F 2202/102 (2013.01); H01S 5/34 (2013.01); H01S 2301/176 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A semiconductor optical device, comprising:
a semiconductor substrate;
a compound semiconductor layer on the semiconductor substrate, the compound semiconductor layer having a mesa portion extending in a stripe shape in a first direction, the compound semiconductor layer having a pedestal portion adjacent to the mesa portion in a second direction perpendicular to the first direction;
an additional insulating film on the pedestal portion of the compound semiconductor layer, the additional insulating film having an upper surface and a side surface at an inner obtuse angle between the upper surface and the side surface;
a passivation film covering the compound semiconductor layer and the additional insulating film except at least part of the mesa portion, the passivation film having a protrusion raised by overlapping with the additional insulating film;
a mesa electrode on the at least part of the mesa portion;
a pad electrode on the passivation film within the protrusion; and
an extraction electrode on the passivation film, the extraction electrode being continuous within and outside the protrusion, the extraction electrode connecting the pad electrode and the mesa electrode, the extraction electrode being narrower in width than the pad electrode.