Why Chips Die


Semiconductor devices contain hundreds of millions of transistors operating at extreme temperatures and in hostile environments, so it should come as no surprise that many of these devices fail to operate as expected or have a finite lifetime. Some devices never make it out of the lab and many others die in the fab. It is hoped that most devices released into products will survive until they be... » read more

Taming NBTI To Improve Device Reliability


Negative-bias temperature instability is a growing issue at the most advanced process nodes, but it also has proven extremely difficult to tame using conventional approaches. That finally may be starting to change. NBTI is an aging mechanism in field-effect transistors that leads to a change of the characteristic curves of a transistor during operation. The result can be a drift toward unint... » read more

Minimizing Chip Aging Effects


Aging kills semiconductors, and it is a growing problem for an increasing number of semiconductor applications—especially as they migrate to more advanced nodes. Additional analysis and prevention methods are becoming necessary for safety critical applications. While some aspects of aging can be mitigated up front, others are tied to the operation of the device. What can an engineering tea... » read more

Chip Aging Becomes Design Problem


Chip aging is a growing problem at advanced nodes, but so far most design teams have not had to deal with it. That will change significantly as new reliability requirements roll out across markets such as automotive, which require a complete analysis of factors that affect aging. Understanding the underlying physics is critical, because it can lead to unexpected results and vulnerabilities. ... » read more

Transistor Aging Intensifies At 10/7nm And Below


Transistor aging and reliability are becoming much more troublesome for design teams at 10nm and below. Concepts like ‘infant mortality’ and 'bathtub curves' are not new to semiconductor design, but they largely dropped out of sight as methodologies and EDA tools improved. To get past infant mortality, a burn-in process would be done, particularly for memories. And for reliability, which... » read more

Improving Transistor Reliability


One of the more important challenges in reliability testing and simulation is the duty cycle dependence of degradation mechanisms such as negative bias temperature instability ([getkc id="278" kc_name="NBTI"]) and hot carrier injection (HCI). For example, as previously discussed, both the shift due to NBTI and the recovery of baseline behavior are very dependent on device workload. This is ... » read more

Thermal Damage To Chips Widens


Heat is becoming a much bigger problem for semiconductor and system design, fueled by higher density and the increasing use of complex chips in markets such as automotive, where reliability is measured in decade-long increments. In the past, heat typically was handled by mechanical engineers, who figured out where to put heat sinks, fans, or holes to funnel heat out of a chassis. But as more... » read more

Reliability After Planar Silicon


Negative bias temperature instability (NBTI) poses a very serious reliability challenge for highly scaled planar silicon transistors, as previously discussed. However, the conventional planar silicon transistor appears to be nearing the end of its life for other reasons, too. The mobility of carriers in silicon limits switching speed even as it becomes more difficult to maintain sufficient elec... » read more

The End Of Silicon?


As transistors shrink, not all device parameters scale at the same rate—and therein lies a potentially huge problem. In recent years, manufacturers have been able to reduce equivalent oxide thickness (EOT) more quickly than operating voltage. As a result, the electric field present in the channel and gate dielectric has been increasing. Moreover, EOT reduction is achieved in part by reduci... » read more