In this paper we evaluate the possibility of extending Time Resolved Emission (TRE) technology towards future low voltage SOI technologies. In particular, we investigate and quantify the gain offered by the InGaAs detector improvements devised by Credence Corp., now DCG Systems, the manufacturer of the Emiscope III PICA system used in this analysis. Experiments on a test chip fabricated in the IBM SOI 65 nm technology will demonstrate that the improved tool guarantees the same Signal-to-Noise Ratio (SNR) even at ~90 mV lower supply voltages. In the second part of the paper we also discuss various other acquisition optimizations of the system. Although the analysis presented here refers to a specific tool, the large majority of the results and discussions can easily be generalized and applied to other PICA systems and detectors, as well as low voltage bulk silicon technologies.

Ultra low voltage probing by time resolved emission (TRE) technology below 1.0V is very challenging for micro-processor debug in practical operation condition. This is because the photo-emission rate reduces exponentially as the power supply voltage decreases. In this paper, a novel technology with improved detector in solid immersion lens (SIL) TRE system was demonstrated for low voltage and small node probing. An improved detecting scheme was developed to collect 30% more photon detection efficiency than the previous system. The SIL TRE with low dark noise detector technology has been successfully applied to optical probing for 45nm product debug. The performance gain improvement in strong and weak signal regime has been demonstrated against the current detector technology. It has also demonstrated the capability on probing the ultra low voltage at 0.75 V for sub micron node of 45nm process.

Internal node timing probing of silicon integrated circuits (ICs) has been a mainstay of the microelectronics industry since very early in its history. In recent years, however, due in part to the increase in the number of interconnection layers and continued proliferation of packaging techniques exposing only the silicon substrate, conventional probing technologies such as e-beam and mechanical probing have become cumbersome or impractical. In an effort to continue transistor-level probing, backside optical probing technologies have been developed and adopted [1]. Chronologically, such techniques include picosecond image circuit analysis (PICA)[2], laser voltage probing (LVP)[3], and dynamic or time-resolved emission (TRE)[4]. In typical examples of backside probing the device under test (DUT) relies on device stimulation from automatic test equipment (ATE) or equivalent bench top setup. This generally requires a specially designed DUT card designed to accommodate a low-profile socket and lid. The DUT card, which is significantly smaller than the tester motherboard, is designed to fit within the chamber opening of the probe system in order to interact with the optical column. Tester stimulation of packaged parts, however, does not address the need to probe the DUT in-situ and in the intended application, such as a PC board. It is often desirable to probe the DUT under conditions typical of the final product or running standardized application based tests. We present here this application and have addressed some of the challenges associated with PC card based optical probing and show successfully performed time-resolved emission on a second-generation advanced graphics processor in a standard graphics card.