Chapter 10
Reliability Analysis of Group III Nitride
LEDs Devices
In addition to productivity and energy saving, another outstanding advantage of IIInitride LEDs is its long lifetime predicted to reach a record of over 10,000 h. Under
normal circumstances, the LEDs would not be instantly total failure, but decays after
a period of operation due to the improper design or production process which may
not meet the operating requirements. In the IES LM-80, the LEDs’ lifetime was
defined as the time required by initial value of light intensity decaying to 70% or
50%. In practical applications, LEDs reliability is closely related to various factors
such as material growth, preparation technology, and packaging process. Therefore,
the overall device performance will be affected by any weakness involved in these
steps. It’s of great importance to raise luminous efficiency and cut the cost for the
further application of III-nitride LEDs. Moreover, how to ensure high reliability and
predict the lifetime of LEDs is becoming increasingly prominent.
Reliability analysis is a multidisciplinary performance test, comprising semiconductor optics, electrics, thermodynamics, chemistry, etc. Reliability analysis generally studies the photoelectric decay properties of LEDs devices through aging tests.
Based on such test, people could predict the lifetime of the LEDs, analyze its decay
mechanism, and find weak steps. People could apply these results in material growth,
chip preparation, packaging technology, etc., to improve the overall reliability of
LEDs devices.
10.1 Failure Mode and Failure Analysis
Because of the complex structure and process of power-type white LEDs devices
represented by GaN-based heterostructures, researchers have also studied the failure
mechanism of GaN-based white LEDs while further improving the luminous efficiency. Studies show the failures that affect GaN-based white LEDs devices can be
divided into two categories: one is the decay or failure of light due to factors such
© Science Press and Springer Nature Singapore Pte Ltd. 2020
J. Li et al., III-Nitrides Light Emitting Diodes: Technology and Applications,
Springer Series in Materials Science 306,
https://doi.org/10.1007/978-981-15-7949-3_10
203
Reliability Analysis of Group III Nitride
LEDs Devices
In addition to productivity and energy saving, another outstanding advantage of IIInitride LEDs is its long lifetime predicted to reach a record of over 10,000 h. Under
normal circumstances, the LEDs would not be instantly total failure, but decays after
a period of operation due to the improper design or production process which may
not meet the operating requirements. In the IES LM-80, the LEDs’ lifetime was
defined as the time required by initial value of light intensity decaying to 70% or
50%. In practical applications, LEDs reliability is closely related to various factors
such as material growth, preparation technology, and packaging process. Therefore,
the overall device performance will be affected by any weakness involved in these
steps. It’s of great importance to raise luminous efficiency and cut the cost for the
further application of III-nitride LEDs. Moreover, how to ensure high reliability and
predict the lifetime of LEDs is becoming increasingly prominent.
Reliability analysis is a multidisciplinary performance test, comprising semiconductor optics, electrics, thermodynamics, chemistry, etc. Reliability analysis generally studies the photoelectric decay properties of LEDs devices through aging tests.
Based on such test, people could predict the lifetime of the LEDs, analyze its decay
mechanism, and find weak steps. People could apply these results in material growth,
chip preparation, packaging technology, etc., to improve the overall reliability of
LEDs devices.
10.1 Failure Mode and Failure Analysis
Because of the complex structure and process of power-type white LEDs devices
represented by GaN-based heterostructures, researchers have also studied the failure
mechanism of GaN-based white LEDs while further improving the luminous efficiency. Studies show the failures that affect GaN-based white LEDs devices can be
divided into two categories: one is the decay or failure of light due to factors such
© Science Press and Springer Nature Singapore Pte Ltd. 2020
J. Li et al., III-Nitrides Light Emitting Diodes: Technology and Applications,
Springer Series in Materials Science 306,
https://doi.org/10.1007/978-981-15-7949-3_10
203