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%.