Title :
A new design-for-test technique for SRAM core-cell stability faults
Author :
Ney, A. ; Dilillo, L. ; Girard, P. ; Pravossoudovitch, S. ; Virazel, A. ; Bastian, M. ; Gouin, V.
Author_Institution :
LIRMM, Univ. of Montpellier/CNRS, Montpellier
Abstract :
Core-cell stability represents the ability of the core-cell to keep the stored data. With the rapid development of semiconductor memories, their test is becoming a major concern in VDSM technologies. It provides information about the SRAM design reliability, and its effectiveness is therefore mandatory for safety applications. Existing core-cell stability design-for-test (DfT) techniques consist in controlling the voltage levels of bit lines to apply a weak write stress on the core-cell under test. If the core-cell is weak, the weak write stress induces the faulty swap of the core-cell. However, these solutions are costly in terms of area and test application time, and generally require modifications of critical parts of the SRAM (core-cell array and/or the structure generating the internal auto-timing). In this paper, we present a new DfT technique for stability fault detection. It consists in modulating the word line activation in order to perform an adjustable weak write stress on the targeted core-cell for stability fault detection. Compared to existing DfT solutions, the proposed technique offers many advantages: programmability, low area overhead, low test application time. Moreover, it does not require any modification of critical parts of the SRAM.
Keywords :
SRAM chips; circuit stability; design for testability; fault diagnosis; integrated circuit reliability; integrated circuit testing; DfT technique; SRAM core-cell stability faults; SRAM design reliability; VDSM technologies; design-for-test technique; low-test application time; semiconductor memories; stability fault detection; Design for testability; Fault detection; Maintenance; Random access memory; Stability; Stress control; System-on-a-chip; Testing; Uniform resource locators; Voltage;
Conference_Titel :
Design, Automation & Test in Europe Conference & Exhibition, 2009. DATE '09.
Conference_Location :
Nice
Print_ISBN :
978-1-4244-3781-8
DOI :
10.1109/DATE.2009.5090873