Temperature control with a thermoelectric cooler (TEC) during laser decapsulation of plastic packages
Ablation was carried out on high voltage Schottky rectifiers at 25°C and −5°C (with a thermoelectric cooler or TEC), at 1.0 W and 3.9 W of laser power. In-situ measurement of the reverse current was conducted and correlated to the device junction temperature. It was found that the usage of a TEC increases the number of laser scans to reach the set current compliance of 100 µA after exposing the die, for ablation at 3.9 W, although eventual damage to the device is still unavoidable. The incorporation of a TEC below the sample is also demonstrated to be effective in reducing the device junction temperature during laser ablation.
Laser decapsulation of plastic packages for failure analysis: Process control and artefact investigations
Laser ablation is a recent pre-decapsulation technique, which is used for sample preparation in failure analysis. This process works with speed and accuracy. These are key parameters for getting successful observation and defect localization. This can be used to have a precise opening on the die. However, this technique can create thermal stresses to the device. In order to minimize this stress, we have investigated methods for controlling the thermal effect of the laser on the component. This paper presents the experimental setup and the study of an electrical artefact that influences the interpretation of our thermal data.
Anomalous Annealing Behavior of Arsenic Implanted Silicon as a Function of Dose and Energy
Anomalous annealing behavior of damage in As implanted Si has been investigated by channeling effect measurements. Room temperature As implants with doses from 1014 to 2 × 1016cm-2 at energies ranging from 50 to 250 keV into Si were annealed over the range of 600°C to 1100°C. Anneal temperatures ≥ 950°C reduce the disorder for ion doses of 0.5 to 1 × 1016 cm-2 at energies between 50 and 250 keV. Anomalously high residual disorder was found for the intermediate doses of 2 × 1014 to 2 × 10/cm2 implanted above 100 keV. For this intermediate dose, annealing of implants performed at liquid nitrogen temperatures did not show significant reduction in this damage. However implants at 200° to 300°C indicate a lower amount of damage compared to the room temperature implants.