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Screening Method for Selection of GaAs-based Semiconductors

IP.com Disclosure Number: IPCOM000104175D
Original Publication Date: 1993-Mar-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 2 page(s) / 47K

Publishing Venue

IBM

Related People

Forster, T: AUTHOR [+3]

Abstract

Reliable long-term performance of laser diodes requires device selection or screening to eliminate those with high probability for early failing. The reliability of GaAs-based laser diodes is strongly related to the long-term stability of their mirrors.

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This is the abbreviated version, containing approximately 60% of the total text.

Screening Method for Selection of GaAs-based Semiconductors

      Reliable long-term performance of laser diodes requires device
selection or screening to eliminate those with high probability for
early failing.  The reliability of GaAs-based laser diodes is
strongly related to the long-term stability of their mirrors.

      A screening technique for such lasers with potential of high
efficiency without adding significantly to the overall cost makes use
of a tracer material at the laser facets.  Suitable tracing materials
are elements which modify the laser-mirror areas with high
susceptibility to degradation, without negatively affecting
good-performing devices.  For AlGaAs/GaAs, sulfur has been found to
be such an element, but certainly other elements can be found.
Sulfide solution treatments effectively improve GaAs surface
properties and are, therefore, used to passivate mirrors of
AlGaAs/GaAs laser diodes.  The effect of the tracing element on the
mirror quality of such lasers can be monitored with an appropriate
microscopic method, for example, EBIC (scanning electron- microscopy
working in the electron beam induced current mode).

      On  operation, mirrors with a high density of defects behave
unstable, and their temperature can increase significantly.  Under
such conditions accelerated diffusion/migration of sulfur into the
crystal occurs.  This results in a shift of the p-n junction out of
its original position, which can be easily detected b...