Semiconductor device and method for manufacturing same
View Patent ↗To suppress or prevent erosion (decrease in film thickness), water absorption, or cracking of a DBR film surface in washing or etching treatment in a downstream process. The DBR film structure of a DBR film 7 D includes a pair of or a plurality of pairs of a deposited SiO 2 film and a deposited TiO 2 film. Such a top layer of DBR film structures has hitherto been a deposited SiO 2 film that provides high reflectance. In order to prevent erosion while maintaining high reflectance, the top layer herein is a high-refractive-index thin film (for example, a deposited TiO 2 film) having a thickness in the range of 1 to 13 nm, and a tapered DBR end portion (a slope having a taper angle in the range of 15 to 45 degrees) is formed by vapor deposition in a lift-off process. The high-refractive-index thin film is overlaid with a reflective metal film 8 D serving as a first layer.
1. A semiconductor light-emitting device, comprising:
a light-emitting structural body including an active layer that emits light; and
a DBR film structure serving as a reflective film, the DBR film structure including:
an inner low-refractive-index film;
a pair of or a plurality of continuously formed pairs of a high-refractive-index film and a low-refractive-index film formed on the inner low-refractive-index film in this order from an inner side to an outer side; and
a thin film with a high-refractive-index formed on the low-refractive-index film in the pair of or an outermost pair among the plurality of continuously formed pairs of the high-refractive-index film and the low-refractive-index film; wherein
the thin film with the high-refractive-index is thinner than the high-refractive-index film, and formed, as a final outermost film serving as a surface of the DBR film structure, to protect the interior of the DBR film structure;
the inner low-refractive-index film is closer to the active layer than any other film included in the DBR film structure; and
the final outermost film is farther from the active layer than an other film included in the DBR film structure.
2. The semiconductor light-emitting device according to claim 1 , wherein the low-refractive-index film is a SiO 2 film, the high-refractive-index film is a TiO 2 film, and the thin film with the high-refractive-index is a TiO 2 film having a thickness in the range of 1 to 13 nm.
3. The semiconductor light-emitting device according to claim 1 , wherein the DBR film structure has a sloped pattern edge portion, and the thickness of the pattern edge portion decreases toward an edge at a cross-sectional taper angle in the range of 15 to 45 degrees.
4. The semiconductor light-emitting device according to claim 1 , further comprising a metal film on the DBR film structure and on an underlayer of the DBR film structure.
5. A method for producing the semiconductor light-emitting device according to claim 3 , comprising a lift-off process of forming a resist pattern having an overhang in cross-section, forming the slope of the DBR film structure around the overhang of the resist pattern by DBR vapor deposition treatment, and removing the resist pattern.