Planar Field-effect Transistors Research Articles

Extremely high frequency hybrid integration—basis of progress in extremely high frequency device technology : R. Kuhn. Nachrichtentechnik: Elektronik25 (12), 445 (1975). (In German)

We report an experimental project to incorporate double-barrier tunnel structures into three-terminal devices. These devices have the negative-differential-resistance (NDR) features of the double barrier, and the added flexibility of a third controlling electrode. One way to make such a device involves the series combination of a double-barrier tunnel structure with a field-effect transistor. We have realized this concept in two types of devices, using samples grown by metalorganic chemical vapor deposition. The devices consist of a GaAsAlxGa1−xAs double-barrier tunneling heterostructure, the current through which is controlled by either an integrated vertical field-effect transistor or a planar metal-semiconductor field effect transistor. The voltage location and peak-to-valley current ratio of the NDR present in the source-drain circuit can be modulated with gate voltage. Experimental results for four samples are presented.

The cylindrical field-effect transistor

The characteristics of a cylindrical field-effect transistor are derived analytically on the basis of Shockley's theory of the planar field-effect transistor. It is found that the cylindrical device is capable of giving twice the (voltage) amplification factor of that of the planar device. Its frequency behavior should be comparable to that of the Shockley unit. Because of the loss of one degree of freedom, the transconductance and power characteristics of the cylindrical field-effect transistor are sharply limited. Experimental data support the analytical results.