Transistors are very important electronic circuit elements. They form the heart of the central processing units. It is thought that the electronic component, that is, the new generation transistors, will cause a revolutionary change in technology. These transistors can be adapted to perform very different tasks. Normally computer chips are made up of electronic components that always do the same thing. But in the future, it is thought to have more flexibility. In a sense, we can say "Smart Transistor is Coming".
New types of adaptive transistors can be dynamically changed as they perform their operation to perform different logic tasks. These types of transistors can fundamentally change the possibilities of chip design.
It will open up completely new opportunities in the field of artificial intelligence, neural networks and even logic that works with values of 0 and more than 1.
To achieve this, scientists at TU Wien (Vienna) relied not on the usual silicon technology, but on germanium. It was an insignificant success.
The world's most flexible transistor is now made using germanium. The study is presented in the journal ACS Nano.
The unique nature of germanium also made it possible to create a prototype that could usher in a new era of chip technology.
Germanium Used in Transistors Revolutionized
The transistor is the foundation of every modern electronic device. Depending on whether an electrical voltage is applied to a control electrode, it either allows current to flow or blocks the flow of current.
The ability to control the current makes it possible to store information as well as the establishment of simple logic circuits.
How the electrical charge is carried in the transistor depends on the material used.
While there may be free moving electrons carrying negative charge in the structure of the transistors, it is also possible for atoms to work in the form of an electron deficient state. With the lack of electrons, these points are positively charged.
These gaps in the orbits of atoms are called holes. These holes can also move in the material.
In the new transistor at TU Wien, both electrons and holes are manipulated simultaneously in a very special way.
Dr. Masiar Sistani explains the mechanism in the structure they have established as follows.
“We connect the two electrodes with an extremely thin wire made of germanium through extremely clean, high-quality interfaces. Above the germanium segment we place a gate electrode like those found in conventional transistors.
What is decisive is that our transistor has another control electrode placed at the interfaces between germanium and metal. It can dynamically program the function of the transistor”.
This device architecture makes it possible to control electrons and holes separately.
“It is a decisive advantage that we use germenium,” says Masiar Sistani. “This is because germanium has a very specific electronic structure.
When you apply voltage, the current flow initially increases as you would expect. But after a certain threshold the current flow decreases again.
This is called negative differential resistance. With the help of the control electrode, we can modulate what voltage this threshold is at.
This process gives freedom to the transistor.”
In this way, for example, a NAND gate can be converted to a NOR gate. NAND and NOR are gates used in logic circuits.
“Until now, the intelligence of electronics came from the interconnections of several transistors, each with a rather primitive functionality. In the future, this intelligence can be transferred to the adaptability of the new transistor itself,” says Prof. Walter Weber.
“Arithmetic operations that previously required 160 transistors are possible with 24 transistors thanks to this increased adaptability.
In this way, the speed and energy efficiency of the circuits can be increased significantly.”
prof. Weber has made an international name for his work on new, reconfigurable electronics.
Dr. Masiar Sistani is an expert in germanium electronics and specializes in researching electronic transport phenomena.
These two areas of expertise are a perfect match to make the adaptive germanium transistor possible.
“Some details still need to be optimized, but with our first programmable germanium transistor we have proven that the basic idea really works. This is a decisive development for us,” says Masiar Sistani.
These new possibilities are of particular interest for applications in the field of artificial intelligence.
“Human intelligence is based on dynamically changing circuits between nerve cells. With the new adaptive transistors, it will now be possible to purposefully modify circuits directly on the chip.
It can be adapted in this way in logical operations. So circuits that work not only with 0 and 1, but also with a larger number of possible states.
A rapid industrial application of this new technology is realistic.
The materials used are already used in the semiconductor industry today and completely new manufacturing processes are not required.
Semiconductor materials are not pure. That is, it is enriched with foreign atoms. In germanium based transistor this is not necessary. Pure germanium can be used.
“We don't want to completely replace the embedded silicon-based transistor technology with our new transistor, that would be arrogant,” says Masiar Sistani.
“The new technology is more likely to be incorporated into computer chips as an add-on in the future.
For some applications, it would just be more energy efficient and convenient to rely on adaptive transistors.” also warns.