Monolithic temperature compensation scheme for field effect transistor integrated circuits
AssigneeHRL Laboratories, LLC
InventorsCarl W. Pobanz, Mehran M. Matloubian
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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.
Claims17
An apparatus comprising a temperature compensating epitaxial resistor having a first resistive component and a second resistive component, wherein said first resistive component includes gallium and arsenic and includes an electrically isolated semi-conducting channel wherein said channel has:
- a width and a length;
- an electrical resistance functionally dependent on channel geometry;
- and said second resistive component is comprised of a substantially conducting material and a plurality of ohmic contacts, wherein said ohmic contacts are functionally interfaced with said first resistive component, and wherein said second resistive component has electrical resistance that is functionally dependent on temperature and geometry and wherein said first and second resistive components have opposite, and independently adjustable, functional temperature dependences.
An apparatus for locally measuring temperature within a circuit, wherein said apparatus comprises two or more reference resistors and two or more temperature indicating resistors, wherein said two or more reference resistors are thermally invariant;
- and are configured as a bridge;
- and wherein said two or more temperature indicating resistors have opposite temperature dependences;
- and wherein one or more of the electrical properties of said two or more temperature indicating resistors and said two or more reference resistors are compared to provide a temperature signal.
Dependencies are inferred from the claim text.