Pinpointing Timing Delays Can Improve Chip Reliability


Growing pressure to improve IC reliability in safety- and mission-critical applications is fueling demand for custom automated test pattern generation (ATPG) to detect small timing delays, and for chip telemetry circuits that can assess timing margin over a chip's lifetime. Knowing the timing margin in signal paths has become an essential component in that reliability. Timing relationships a... » read more

Geo-Spatial Outlier Detection


Comparing die test results with other die on a wafer helps identify outliers, but combining that data with the exact location of an outlier offers a much deeper understanding of what can go wrong and why. The main idea in outlier detection is to find something in or on a die that is different from all the other dies on a wafer. Doing this in the context of a die’s neighbor has become easie... » read more

Better Inspection, Higher Yield


Wafers can be inspected for large, obvious defects, or for small, subtle ones. The former is referred to as macro-inspection, while the latter is micro-inspection. These processes use different machines with different capital and operating costs, and they might look like competing approaches with different economic returns. In fact, they are complementary tactics that can be balanced within an ... » read more

Pattern Matching in Design and Verification


Pattern matching (PM) was first introduced as the semiconductor industry began to shift from simple one-dimensional rule checks to the two-dimensional checks required by sub-resolution lithography. These rule checks proved far more complex to write, hard to code for fast runtimes, and difficult to debug. Incorporating an automated visual capture and compare process enabled designers to define t... » read more

Yield Ramp Challenges Increase


As semiconductor manufacturing moves down to smaller process nodes, there’s no doubt that it is increasingly difficult to ramp both test and manufacturing yields. One reason for this is simply scale. Smaller nodes translate into more steps and greater complexity in the manufacturing process, with attendant process variations. “Smaller process nodes increase the amount of embedded mem... » read more