Silicon Oxide Works as a Memristor and Resistive RAMCategory: Science & Technology
Posted: May 21, 2012 10:22AM
While working with silicon oxide to develop silicon-based LEDs, researchers at the University College London constantly ran into problems and it appeared their devices were unstable. Naturally one of the PhD students was instructed to analyze the material's electrical properties and found that it was switching from a conductive to a resistive state, which was causing the problems. However, the material was not unstable. Quite the opposite as these flips were happening in a predictable way, and now the researchers have used it to create the first pure silicon oxide-based Resistive RAM (ReRAM).
The key to the ReRAM is that the silicon in the silicon oxide will spontaneously form filaments within the crystal structure, when a voltage is applied. These filaments conduct electricity better than the silicon oxide around them, so their presence represents the switch between states. This allows the memory to operate on just a thousandth of the power Flash memory requires, while also being 100 times faster. Another major development with this though is that it can operate in ambient conditions. Current ReRAM designs require the device be in a vacuum, which makes the system fragile.
While we may first see this silicon oxide material used in ReRAM, it also has promise as a memristor. Memristors remember the last voltage applied to them, which may allow electronics to mimic neurons in the human brain. The key is that this material's resistance lies on a continuum and can be set by the last voltage applied to it. Also, as the material is transparent, we may see it used in transparent electronics sometime in the future.