InGaN/GaN/AlGaN-based laser diodes grown on epitaxially laterally
overgrown GaN
S. Nakamura
(Nichia Chemical Industries, Ltd.)
Epitaxially laterally overgrown GaN on sapphire was used to reduce
the number of threading dislocations originating from the interface of
the GaN epilayer with the sapphire substrate. The GaN layer above the SiO2
mask area surrounding the window and corresponding to the lateral overgrowth
was nearly free of threading dislocations. A high density of threading
dislocations was observed in the vicinity of GaN grown in the window regions.
InGaN multiquantum-well-structure laser diodes (LDs) grown on pure GaN
substrates, which were fabricated by removing the sapphire substrate, were
demonstrated. The LDs with output power of 5 mW exhibited a lifetime of
more than 290 h and an estimated lifetime of 10,000 hours despite a relatively
large threshold current density. The far-field pattern of the LDs with
a cleaved mirror facet revealed single-mode emission without any interference
effects.
Order No.: JA907-006 © 1999 MRS