In semiconductor industries, development of new technologies and new products generally follows a phase of yield improvement where Failure Analysis expertise is used to locate and fix killer defects and for design debug. When process and design reach a certain level of maturity, a second phase of optimization, qualification and reliability is executed in which Failure Analysis expertise is used for internal timing characterization of integrated circuit and results are compared with design/process simulations. In order to reduce the cost of testing during manufacturing, circuits embed Built in Self Timing Characterizer (BISC) for timing measurements inside critical functional blocks. Thanks to advanced integration, the last CMOS technologies allow high performance in terms of speed. Arithmetic and Logical Units (ALU) are able to work at frequencies greater than few GHz and some memories’ access time is lower than hundreds picoseconds. In the CMOS 40nm analysis case study presented in this paper, a BISC measurement of memories’ access times gives different results than what was expected from simulation. Internal probing becomes mandatory to understand this critical timing issue. A complete comparison is done between the 3 contactless probing techniques available in our laboratory which are the E-Beam Testing (EBT), Time Resolved Emission (TRE) and the recent Laser Voltage Probing (LVP) to highlight strength and weakness of each probing techniques in front of this timing related defect. We demonstrate that the LVP is an inevitable technique to address the nanometer-scale technologies in terms of spatial resolution, low voltage measurements and timing performance.