Multilayer Field Effect Transistor Channel Resistance Control
Original Publication Date: 1986-Dec-01
Included in the Prior Art Database: 2005-Mar-09
Publishing Venue
IBM
Related People
Frank, DJ: AUTHOR [+3]
Abstract
The resistance in a multilayer field effect transistor channel can be lowered through appropriate potential and charge levels in a surface layer.
Multilayer Field Effect Transistor Channel Resistance Control
The resistance in a multilayer field effect transistor channel can be lowered through appropriate potential and charge levels in a surface layer.
The improvement is shown in the figure for a GaAs surface layer on an AlGaAs underlayer on a GaAs substrate.
(Image Omitted)
In the absence of the GaAs surface layer, surface states in the gap region of the above device operate to pin the Fermi level at the surface and reduce the number of carriers in the channel in the gap region of the device, thus increasing its resistance. The surface layer reduces this effect. The surface layer thickness and doping are chosen such that, under normal operatin conditions, the surface layer is fully depleted and non-conductive, and the charge of the depleted surface layer substanti counteracts the charge of the surface states. In this way, the number of carriers in the gap region channel is not reduced as far, resulting in lower resistance.
Disclosed anonymously.
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