Reliable Method of Catastrophic Optical Mirror Damage Identification in Semiconductor Laser Diodes
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Jakubowicz, A: AUTHOR [+2]
A microscopy method is described which allows to identify catastrophic optical mirror damages in semiconductor laser diodes.
Reliable Method of Catastrophic Optical Mirror Damage
in Semiconductor Laser Diodes
method is described which allows to identify
catastrophic optical mirror damages in semiconductor laser diodes.
Optical Mirror Damage (COMD) is a major failure
mode of GaAs-based laser diodes, and thus it is a major limiting
factor in terms of reliability of these devices. Therefore many
efforts have been made in the past, and are still made, to eliminate
COMD. Since COMD is only one among several failure modes of laser
diodes, there is a need for fast and non-destructive methods which
allow its unambiguous identification. In this respect the most
reliable technique seems to be the inspection of the laser mirror
with a standard Scanning Electron Microscope (SEM). Due to the SEMs
high resolution it is easy to detect the mechanical damage of the
mirror. However, this is true only in the case of uncoated mirrors.
When the mirrors are coated (e.g., with insulating layers), the
coating can mask the mechanical damage of the semiconductor's mirror
facet. Thus, as long as the coating is not damaged, it is very
difficult to identify unambiguously the occurrence of COMD.
microscopy method is proposed which makes possible
an unambiguous identification of the occurrence of COMD. The
proposed method is non-destructive, fast, and can be applied in
reliability studies of laser diodes routinely.