Dynamic Thermal Laser Stimulation Theory and Applications

Abstract

Thermal Laser Stimulation (TLS) techniques have demonstrated their ability to detect and locate defects in integrated circuits (IC). Optical Beam Induced Resistance Change (OBIRCH) and all derivatives are based on the same physical principle: local laser heating of integrated circuits.The purpose of this paper is to synthesize the extensive work done in this area in order to highlight the essential physical principles. With this knowledge Dynamic Thermal Laser Stimulation (D-TLS) applications can then be tackled, optimizing parameters such as laser dwell time for sufficient heating. Finally, applications will be presented on 180nm, 120nm and 90nm, comparing the sensitivity of Dynamic Thermal Laser Stimulation with respect to light emission.

Fault localization by Dynamic Laser Stimulation extended testing

“…DLS approaches based on analog information rather than on binary pass or fail information have been proposed [13,14,15]. Those analog Variation Mapping techniques can be referred to as xVM where x being the analyzed parameter.…”

“…Any critical parameter could be monitored according to the device or test structure under test. For instance, it could be the Delay (D), the Frequency (F), or the Phase (P) which we respectively refer to as DVM [13], FVM [14] and PVM [15].…”

Dynamic laser stimulation techniques for advanced failure analysis and design debug applications

“…TLS will also cause timing variations but to a lesser extent. However in the presence of defects the thermally induced resistance changes can significantly affect the device dynamic behavior [12].…”

“…Dynamic Laser Stimulation approaches based on analog information rather than on binary pass or fail information have been proposed [10][11][12][13][14][15]. Those analog Variation Mapping techniques can be referred to as xVM where x being the analyzed parameter.…”

A challenging case study resolved by using the Dynamic Laser Stimulation technique

“…Dynamic Laser Stimulation (DLS) [1][2][3] techniques are used to highlight and localize defects that appear when the device is running. These kinds of defects are called soft defects [4].…”