Dynamic Laser Stimulation (DLS) techniques proved to be very efficient in soft defect localization bringing a lot of information about the device internal behavior. We need to use external parameter measurements such as frequency, delay, voltage etc to perform these techniques. So they can't be used to study internal signal propagation problems in latched device since signals are resynchronized. We will show that we can use the power analysis coupled with DLS techniques set up to characterize soft defect when we don't have a direct access to monitored signal propagation such as in some transistor transition issues. Laser stimulation in addition of power analysis is used to decrypt security codes in security chip, but in failure analysis it is a new way to reach internal information in order to localize soft defects.

Limitations of backside optical techniques for failure analysis of dynamically activated devices have underlined the need to extend the capabilities of Dynamic Laser Stimulation techniques (DLS). DLS techniques provide a precise localization of the dynamically failing area, but it lacks timing information as the fault is often related to a specific test vector. Optical probing techniques such as TRE and LVP [1, 2] are hardly applicable on cases with long test loop and for which no preliminary information is available on the time window of interest. Defect localization and electrical tests can be coupled in order to provide more accurate information about the failure, especially vector information in addition to x and y localization. We have developed a Full Dynamic Laser Stimulation (F-DLS) approach based on laser modulation by electro optic modulator to face this challenge. The purpose of this paper is to present DLS limitations, our motivations, comparisons with other DLS extensions, FDLS implementation on our system, application example and future F-DLS developments.

A key point to guarantee electronic device quality is device qualification. This part of the process is a significant contributor to the time and cost of the development and production of any electronic device. A device is required to perform a task and its operational lifetime is a key issue for the end user. The more sensitive the qualification technique is, the faster marginalities in the device parameters could be observed. Dynamic Laser Stimulation techniques fill this requirement and could be used in conjunction with traditional qualification procedures.