Radiation sensor and dosimeter incorporating same

Abstract

In a dosimeter probe comprising a semiconductor diode or a field effect transistor for monitoring levels of radiation during medical procedures, such as the treatment of tumors, the transistor or diode is fabricated epitaxially upon a surface of a substrate and a dummy die, i.e., a slab of material similar to that of the substrate, is positioned adjacent the substrate surface so as to overlie an active region of the transistor or diode and a relatively large area of the substrate surrounding the active region. The arrangement is such that, whatever the direction from which the radiation is incident upon the active region, its path through the device before arriving at the active region will have similar characteristics to the path the radiation takes upon leaving the active region.

Dependencies are inferred from the claim text.