User:Ldeasey/Ballistic Transistor 2

Ballistic Transistor

A ballistic transistor is a type of electronic component that will lead to smaller and faster integrated circuits. A typical transistor starts and stops the electron stream into a collector where no electrons collected is a logical 0, and a collection of electrons is a logical 1. The ballistic transistor differs from a typical transistor because it uses electromagnetic forces to steer each electron to bounce off of a deflecting obstacle either to the logical 0 side or the logical 1 side of the transistor. This transistor operates at far greater speeds and a lot less noise than a typical transistor. This new transistor will eventually lead to enormous improvements to the electronics world, but as of now it is still in the prototyping stage.

Operation

The Ballistic Deflection Transistor, or more commonly abbreviated as BDT, resembles a four way intersection, but it has a triangular obstacle in the middle. From the “south” road an electron is fired into the transistor and encounters an electromagnetic field along the “south” road that slightly steers it either to the left or right. When the electron reaches the middle of the intersection, it hits the left or right side of the obstacle and veers into the left or right path. If the electron goes down the left path, a logical 0 is asserted by the transistor, but if it goes down the right path, a logical 1 is asserted. The operation is described as being like a game of atomic billiards. A typical traditional transistor operates by moving a stream of electrons over a capacitor. If the capacitor “collects” a number of electrons, it asserts a logical 1, and then when those electrons are moved off the capacitor, it asserts a logical 0. This operation is described as a stream of water collecting and emptying from a bucket.

Advantages

Smaller

What makes a BDT ballistic is the material it is made out of and how it is formed. A technique of “growing” a gate oxide on a silicon wafer was created by Bell Labs that created a smooth path of travel for the electrons. Making the channels the electrons travelled through shorter and smoother allowed the electrons to encounter less resistance and move faster. This then allowed transistors to be made much smaller and still operate at the proper speeds. The way that the BDT is designed on a nano-scale level was all but impossible a couple years ago. The way the “large” prototype is being built is already as small as the smallest and best traditional transistors being made today. The researchers creating this prototype are confident that this design will be able to be downscaled even further in the future.

Faster

The drawback of a traditional transistor is that is takes time to empty and collect that bucket of water that represents the capacitor and takes energy to turn that stream of electrons on and off. The BDT bounces each electron off of the deflecting obstacle using its own energy and momentum and does not have to stop and start the stream of electrons in order to differentiate between the logical 0 and 1 signals. This allows the BDT to operate at much higher speeds. The BDT can operate at such high speeds it is reaching the terahertz level. This is a thousand times faster than a typical transistor and the fact that it is so fast is actually a hurdle the design team has to solve. The BDT operates so fast that a typical oscilloscope used to test transistors can’t be used because it cannot operate at such a high speed.

Less Power

The BDT will produce much less heat and require a lot less power than the typical transistor. This is because the BDT does not need to turn the stream of electrons on and off as it operates which is the source of most of the heat produced and energy used by traditional transistors. The fact that the transistor already produces 5 times less heat than a non-ballistic transistor because the electrons aren’t bouncing off of and catching on rough edges of the path they travel on. The way the BDT operates just decreases that heat produced even less. The voltage that the BDT requires is also very low because of the small amount of energy it requires to work. It is projected to use only 10% the amount of power that a traditional transistor uses. The way the BDT is designed means that this percentage will only improve and the signal will become even more accurate as the design gets smaller.

Future Applications

Right now the BDT is still in its prototype stage. The National Science Foundation awarded the University of Rochester, where the BDT design was created, a $1.1 million grant in order to create this prototype. When the prototype is improved and tested enough to become available to the market the BDT will revolutionize the electronics manufacturing field. The BDT will be used in ultra-high speed analog, digital, and mixed circuits and will operate in the THz range. It will be used in high speed telecommunications and in THz analog to digital converters used in software radio.