Microprocessors are the building blocks of modern computers and other processing devices. By miniaturizing hardware, companies like Intel and Apple have managed to put billions of transistors in a narrow few inches behind a screen. Microprocessors normally consist of a few integrated circuits, or even one integrated circuit which has all of the core functionality of a central processing unit.
The first “2D” microprocessor has been created. It has a surface area nearly 100 times larger than modern silicon standards at roughly 0.6mm2, but was designed that way intentionally to account for non fault tolerant processes. The processor was made out of a transition-metal dichalcogenide (TMD) that is used by the Vienna University of Technology. The processor is approximately 3 atoms thick.
What is the microprocessor made of?
TMD consists of a transition metal (normally Tungsten or Molybdenum) and a Chalcogen (elements in group 6A on the periodic table). These elements work together to form a semiconductor as opposed to the constant conductivity of graphene. Of the Molybdenum components produced, only a small percentage were viable for use in the processor.
How does this microprocessor improve on computing?
Though the device can only process one bit of information at a time, it is capable of processing information from external memory and performing four operations on data. Given that previous 2D electronics consisted of sufficient numbers of transistors to be counted on fingers and toes, this device made of 115 transistors has proven to be a true leap in terms of silicon alternative computing as described by The Verge.
Traditional silicon computers are limited to approximately 5 nanometers or 1/20,000th of a human hair in size. Thomas Müller believes that the scaling limit for silicon alternative processors leads down to 1 nanometer, five times smaller than modern silicon components,
Where is this technology headed?
The Register reports that Thomas Müller expects that scaling the 1 bit processor up to an 8 bit processor can be accomplished without significant issue. While this processor does offer significant size benefits, the complexity of producing the components and lack of current fault tolerance has both forced a larger design and lacks the complexity required to compete with modern silicon chipsets.
Silicon alternatives are, however, alternatives, at this time they are being examined to fill in gaps for applications where 3D silicon components are too large or too rigid to be used. Silicon alternatives also provide reduced power consumption for their constituent parts.
Graphene microtransistors have been experimented with, and bi-layer graphene has shown logic switching capabilities as efficient as 10,000 switches on 100 millivolts. The molybdenum disulfide processor proposed by the Müller team has been shown to operate on as little as 60 millivolts per 2,000 to 20,000 switches
TMD processors currently suffer from high rigidity as a result of placement on silicon wafers, innately rigid structures. According to IEEE Spectrum, the Vienna team is working to produce a similar design that relies on molybdenum film collecting directly on silicon wafers as opposed to sapphire and being harvested. If successful, it is expected that production reliability of components will increase significantly.
The power wall discussed in our Light Speed Computing article with respect to silicon components also applies to scalability in terms of size, traditional transistors with thicker structures are much harder to cool and waste significant amounts of energy through waste heat. Transistors capable of operating at the thickness of 3 atoms should, theoretically produce lower concentrations of waste heat which can be dealt with more easily.
Advancements made in recent times in terms of component miniaturization have been significant. If the current trends continue, it may be possible to see commercialized 3 atom thickness processors within this generation. Though they are not likely to overtake silicon-based processors in the short or medium term, they will likely reach maturity with haste as consumer demand continues to increase.