Abstract:
A method and apparatus for substantially canceling the effects of temperature on the electrical performance of Field Effect Transistor (FET) integrated circuits (IC's) by exploiting a subtle feature of an epitaxial resistor implemented in an FET process. Specifically, the invention takes advantage of two constituent epitaxial resistor components having resistances that vary monotonically in opposite directions as functions of temperature. The invention includes a method for selecting the geometry of such an epitaxial resistor to give it either temperature invariance or a specific, useful functional temperature dependence.
Abstract:
A method and apparatus of substantially canceling the effects of temperature on the electrical performance of Field Effect Transistor (FET) integrated circuits (IC's) by exploiting a subtle feature of an epitaxial resistor implemented in an FET process. Specifically, the invention takes advantage of two constituent epitaxial resistor components having resistances that vary monotonically in opposite directions as functions of temperature. The essential components include: a plurality of ohmic contacts (100), and an isolated semi-conductor channel (102) residing in a layered semiconductor. The resistance of the epitaxial resistor R of the invention is comprised of an aggregate of resistances (FIG. 1c). The invention includes a method for selecting the geometry of such an epitaxial resistor to give it either temperature invariance or a specific, useful functional temperature dependence.