The use of optical techniques for attacking integrated circuits (ICs) is increasingly being reported, particularly the nefarious extraction data from embedded SRAM. Such attacks can provide access to highly sensitive information such as encryption keys and bypass various security measures. Attackers usually exploit one of several interactions between light and semiconductors to generate logic-state images that reflect data in memory. Thermal laser stimulation (TLS) and laser probing via electro-optical frequency mapping (EOFM) have been reported in the literature, but photoelectric laser stimulation (PLS) gets little attention. Considering the potential advantages of PLS over other techniques (e.g., less power is required to generate current-voltage changes and the effect can be triggered at shorter wavelengths, which can lead to improved spatial resolution), the authors set out to determine if logic state images can be generated from various types of devices with PLS and assess the strengths and limitations for each case. The results of the investigation are presented in this paper.

Dual-beam focused ion beam (DB-FIB) system is widely used in the semiconductor industry to prepare cross-sections and transmission electron microscopy (TEM) lamellae, modify semiconductor devices and verify layout. One of the factors that limits its success rate is sample charging, which is caused by a lack of conductive path to discharge the accumulated charges. In this paper, an approach using an insitu micromanipulator was investigated to alleviate the charging effects. With this approach, a simple front side semiconductor device modification was carried out and the corresponding stage current was monitored to correlate to the milling process.

Although pre-laser decapsulation reduces the time to acid exposure for subsequent chemical decapsulation of copper wirebonded devices, it can result in severely damaged or broken copper wirebonds if carried out at a focused depth followed by chemical decapsulation. Thin quad flat packages (TQFPs) of dimensions 22 mm × 22 mm, with copper wirebonds were pre-laser decapped (Nd:YAG laser, 1064 nm) at three depths of focus, at focus, (z-0.5) mm and (z-1) mm. Reducing the laser focus depth by 1 mm, followed by subsequent chemical decapsulation, resulted in the least damage to copper wirebonds. Average percentage reduction in copper wirebond diameter after complete (laser and chemical) decapsulation is about 2.30%.

In this paper, the application of pulsed-TIVA for the localization of Cu/low- k interconnect reliability defects in comb test structures is described. Two types of subtle dielectric defects which are otherwise not detectable with conventional TIVA can be detected with pulsed-TIVA.