Process monitor test chip and methodology

摘要

A process monitor test chip and methodology allows process-related manufacturing defects to be quickly identified and isolated. A basic circuit block of a test chip having a number of inverter cells serially connected with a corresponding number of observation points before the input of each inverter cell provides for the inverter cells in the basic circuit block to be probed and thus observed by e-beam technology. Any required number of basic circuit blocks may be serially connected end to end to constitute a chain circuit. Within the test chip itself, a plurality of chain circuits may be connected serially or in parallel to accomplish different testing goals. By controlling an input signal and a control signal of a multiplexing element associated with each chain circuit, the plurality of chain circuits can be forced into a serial connection or a parallel connection. In a serial mode, the plurality of chain circuits are serially connected with one input signal and one output signal of the test chip; the serial connection may be used during burn-in of the test chip to test for whether the test chip contains any process-related manufacturing defects. Once it has been determined that the test chip does contain process-related manufacturing defects, the parallel connection allows the defects of the test chip to be quickly isolated.