Low-k test regime spots defects on wafers

Columbia's innovation
Columbia uses photo-induced current (via UV lights) and laser-based second-harmonic generation in a photo-excitement approach that can be performed quickly, without requiring contact probes. "We have shown that if you photo excite the carriers, you can accelerate the normal TDDB testing regime down from years to days," said Robert Laibowitz, a senior research scientist at Columbia. "Our techniques are also suitable for testing in a fab, because they are contactless. For instance, in one test we just shine the laser on the finished wafer and study the reflections from the surface" to detect traps.

The three-year SRC contract runs through January 2011, at which time Columbia is expected to provide SRC members with a regime for determining electron barrier heights, trap levels and trap densities in any low-k dielectric thin film, as well as within the interfaces between the film and adjacent materials.

SRC members include Advanced Micro Devices, Applied Materials, Axcelis Technologies, Cadence Design Systems, Freescale Semiconductor, Hewlett-Packard, IBM, Intel, LSI Corp., Mentor Graphics, Micron Technology, Mitre, Novellus Systems, Rohm and Haas Electronic Materials, Texas Instruments, Tokyo Electron and Xilinx.