Correlating defects to functional and I/sub DDQ/ tests

Abstract

Functional tests and IDDQ tests are studied to determine their effectiveness toward screening failures. A model is presented for curve jitting correlation data between fault coverages and defect quality employing the Williams and Brown defect level to fault coverage equation. The model is used for multiple test types. Empirical data were gathered to demonstrate its effectiveness over functional and IDDQ tests. IDDQ test data demonstrates two categories of IDDQ defects: pattem sensitive and pattem insensitive defects.trade-off between functional and I D m tests for at least one ASIC technology.

On-chip I/sub DDQ/ testing in the AE11 fail-stop controller

“…As demonstrated by Powell et al, 10 this method maximizes the obtained test coverage, assuming that the pseudorandom pattern generator can stimulate as many different states in the circuitry as possible. Bardell et al 2 …”

Experimental results for IDDQ and VLV testing

“…Maxwell et al have shown the relative performance of several tests [5]. Powell et al have analyzed some experimental data to correlate defects to functional and IDDQ tests [6]. In ITC'96, we only showed the statistics of defect classes [4].…”