Extract IC through its backside and acquire its firmware is quite normal in the IC extracting industry.
Carry out the same operation through the bottom side of IC can achieve the extracting result too. But the IC extracting operation could be more difficult than from the top side. From one aspect, it is not easy to find the security fuse location from the IC backside. From the other side, IC extracter can use brutal mechanical force to de-capsulate the IC which can avoid the usage of strong acid solution. Anyway, IC extracter can take the top side optical photography as reference to locate its security fuse, or use infrared lens to locate it.
Although there is not enough 1 to 1.1 microns infrared light can be obtained from halogen light bulbs which will be used to ionized effective zone of transistor from the backside of IC when IC extract, but tremendous ions pair of holes from the silicon button will fall onto the effective area before mutual combination.
Unfortunately, this kind of IC extract method can’t deal with the modern low featured size IC. Top metal layer can prevent the light from reaching the effective area, complanation can decrease the transparency of oxidation layer when extract IC, and strength the light separation. High doping potency can decrease the light penetration from backside of IC when extract it. Smaller transistor requires to use stronger radiation to extract IC.
Ultraviolet EEPROM memorizer unit is not so sensitive to the light IC extract method, as a result of that, IC extracter need to more powerful current to stimulate it. However, the fact is flash lamp or general light bulb can be used to extract the IC security fuse, and still need to design the security method to keep away from the IC extract carefully. For instance, security fuse shouldn’t be placed in the area where is far away from the main memorizer which can cause the extract IC become easier. At the same time, light and radiation sensor can use to inspect the ion radiation, reset the IC before the sensitive and important information being released.
