High density interconnect verification using voltage contrast electron beam

High reliability testing of multi-chip module (MCM) substrates has been demonstrated using voltage contrast electron beam (VCEB) open-shorts testing. Features as small as 100 μm are probed over an area of 10 cm×10 cm in a tool developed by installing high-precision digital electronics and a novel large field of view secondary electron analyzer into a conventional scanning electron microscope. These modifications in conjunction with sophisticated calibration and data analysis techniques have produced the research tool which is now routinely used to test substrates fabricated at Microelectronics and Computer Technology Corporation (MCC) as well as many fabricated by MCC´s shareholders. The performance of the system was assessed by testing MCM product substrates and special test substrates. Various combinations of conductors and insulators were tested. The test targets were designed with numerous feature sizes over the entire field of view so that probing accuracy and test uniformity could be characterized