China just created the world's smallest transistor gate chip

Moore's Law has powered our lives for a while, and it's not dead yet. Chip manufacturers are trying to speed up the miniaturization of transistors to further write this law.

Recently, a research team in China seems to have created the world's smallest transistors.

China seems to have just created the world's smallest transistors.

Over the past few decades, scientists and engineers have tried to miniaturize transistors to the point where, in their smallest cases, they consist of only dozens of atoms. Since the first integrated circuits appeared in the 1950s, the rate of progress in miniaturizing transistors has followed Moore's Law, which predicts that the density of active components in integrated chips will double. every 2 years.

Unfortunately, progress in this direction has slowed considerably in recent years. The main reason behind this is that we are rapidly approaching the physical limits of the most materials and manufacturing processes available.

Graphene materials and carbon nanotubes are important in making small transistors.

More specifically, we cannot make gate transistors, which control the current from source to groove, smaller than 5nm because something called quantum tunneling prevents them from working as intended.

Materials such as graphene and carbon nanotubes could be important in making smaller transistors due to their physical properties, but creating the devices will take some time.

In a paper released this week, Chinese researchers say they have created a transistor with the smallest gate length ever reported. This milestone was accomplished by using graphene as well as molybdenum disulfide creatively, stacking them in a two-step staircase structure.

At the higher level, we have the source, and at the lower level, we have the groove. Both are made of palladium titanium alloy, separated by the face of the stairs – which is made of a semiconductor material called molybdenum disulfide, which itself sits on top of a layer of hafnium dioxide, which acts as a substance electrical insulation.

This design utilizes the edge of the graphene sheets.

The inside of the higher order is an aluminum sandwich layer, covered with aluminum oxide, which sits on top of a sheet of graphene – a single layer of carbon atoms. Aluminum oxide acts as an insulator, except for a small gap in the vertical wall of the higher order, where the graphene sheet is allowed to come into contact with molybdenum disulfide. This entire staircase structure rests on a thick layer of silicon dioxide.

This design utilizes the edge of the graphene sheets. That means when the gate is set to the 'on' state and is only 0.34nm wide, which is essentially the width of the graphene layer itself. Another notable feature of this 'wall transistor' is the negligible current leakage due to the higher out-of-state resistance.

Manufacturers can take advantage of this result for low-power applications. Best of all, it should be relatively easy to build, although many prototypes require quite a bit of voltage to drive.

A gate size smaller than 0.34nm is almost impossible.

The study's co-author, Tsinghua University researcher Tian-Ling Ren, said that this could be 'the final tipping point for Moore's Law'. He also believes that a gate size smaller than 0.34nm is almost impossible.

Of course, the researchers behind the transistor have only shown that a transistor can be made of a single-atom-thin material, without inventing a new process to precisely position the required layers. Reliable fabrication of these billions of wall transistors is still a distant dream but is an important step in the way forward in hopes of faster, more economical devices in the future.

Meanwhile, Samsung, Intel and TSMC are working hard to make GAA-FET (gate-all-around) transistors a reality, standardizing interconnections for chiplet designs.