Defective chips can still be used

Researchers think they have devised a method whereby defective chips can still be used in computers or smartphones. This would not only increase chip yields, but also result in more efficient equipment.

A chip that comes from a wafer and shows defects is currently thrown away in many cases, especially when it concerns processors or socs. Chips that do not function correctly could, however, be used in computers or smartphones, says Andreas Burg. Burg heads the Telecommunications Circuits Lab of the École polytechnique fédérale de Lausanne, a Swiss research institute. His lab is concerned with data transfer and, as with data transmission, tolerance for errors could also be introduced in processors.

That would allow the use of ‘damaged’ chips and thus entail higher ‘yields’ or yields per wafer; fewer defective chips have to be thrown away. Moreover, such chips could be more easily produced on a smaller process, because the associated higher probability of failure does not constitute an obstacle to use. That would make further downsizing of chips more feasible, says Burg. Smaller production processes mean lower energy consumption, making equipment more economical.

By copying fault tolerance from data networks, processors could operate at a very low voltage, with errors occurring more quickly. Especially telephones are cited as an example; which could switch to a low-power mode, where the low operating voltage can cause errors and minor delays. Fault tolerance would allow a phone to still function with a low battery, albeit a little slower to make up for the errors. In a simulation, memory corruption appeared to have little influence on the functioning of a telephone.