Hot Electron Injection Field Effect Transistor ("HEIFET")

The purpose of the proposed research is to experimentally prove the idea that the upper frequency limit of a field effect transistor can be significantly increased by replacing the highly doped source contact by a hot elctron injection contact of the type used in the planar injection limited Gunn diode, also called "field effect controlled transferred electron device" or "FECTED". The injection limiting contact which consists of an ohmic contact and an overlapping Schottky gate injects hot and, hence, fast electrons into the FET-channel thereby drastically reducing the total transit time through the channel. The new FET, which is called "hot electron injection field effect transistor" or "HEIFET" is not subject to the slow acceleration process electrons experience when injected from a highly doped source contact (the standard source contact of conventional field effect transistors) where the electric field and, hence, the velocity of electrons is very low. A patent on the HEIFET is pending. In order to achieve the objective of the proposed research a 60GHz HEIFET will be designed, fabricated and tested. The main goal of this project is to achieve several milliwatts of oscillatory output power with efficiencies of more than 5% at 60GHz. If such a high performance could be obtained the device would be an attractive candidate for developing low-cost multi-purpose distance sensors for industrial, automotive and domestic use.