Australia has developed the perfect "single atom transistor"

Australian scientists say they have developed a single-atom transistor consisting of a single phosphor atom etched in a silicon crystal, with gates controlling the current and metal contacts at the atom level, which are expected to become the basic components of the next generation of quantum computers. The study was published in the February 19 issue of Nature Nanotechnology.

In the latest research, scientists used a silicon wafer placed in a vacuum to make the single-atom transistor. In order to observe and manipulate the atoms located on the surface of the silicon wafer, they first cover the transistor with a layer of unreactive hydrogen atoms, and then use the ultra-fine metal tip of the scanning tunneling microscope to precisely select certain regions of hydrogen atoms to be selective. The ground was removed, exposing two pairs of mutually perpendicular silicon ribbons plus a small rectangle of six silicon atoms located at the junction of these silicon ribbons.

Then, the scientists added phosphine (PH3) gas and heated it, causing the phosphorus atoms to attach to the place where the silicon was exposed. Because it is rectangular, only one phosphorus atom enters the silicon network, resulting in four mutually perpendicular phosphorus electrodes. And a phosphorus atom. The distance between a pair of electrodes is 108 nanometers. After a voltage is applied between them, the current can pass through a single phosphorus atom and flow between two other vertical electrodes that are only 20 nanometers apart. In this way, phosphorus atoms act like transistors.

Scientists said that this is not the first single-atom transistor, but the new transistor can be placed more precisely, which makes it more useful.

According to research leader Michel Simmons, director of the Quantum Computing and Communication Center at the University of New South Wales, “Our newly developed equipment is perfect. This is the first time that scientists have demonstrated that they can handle very precisely on a single pedestal. Single atom."

Although the transistor can only operate in temperatures below 1 degree Kelvin (minus 272.15 degrees Celsius), the latest technological advances are expected to allow transistors to reach a single atomic level faster; scientists can also learn that once the device reaches atomic level, they How will it work? Scientists predict that the transistor will reach a single atomic level by 2020 in line with Moore's law.

From the electron tube to the transistor to the integrated circuit, the smaller component volume has always been the goal pursued by computer engineers. Today, scientists only squeeze more components on silicon chips and build more logic circuits in a limited volume to have faster computing speeds. Single-atom based transistors undoubtedly give people reason to expect smaller, faster computers. More importantly, the success of Australian scientists is more derived from accurate design than luck, which makes the reproducibility of single-atom transistors much more likely to go beyond the laboratory.