Method for radiation monitoring
A radiation dosimeter includes a semiconductor substrate and a buried insulator layer disposed on the semiconductor substrate. The buried insulator layer has a plurality of charge traps. A semiconductor layer is disposed on the buried insulator layer. The semiconductor layer has an emitter, an intrinsic base, and a collector laterally arranged with respect to one another. In response to radiation exposure by the radiation dosimeter, positive charges are trapped in the plurality of charge traps in the buried insulator layer, the amount of positive charge trapped being used to determine the amount of radiation exposure. A method for radiation dosimetry includes providing a radiation dosimeter, where the radiation dosimeter includes a lateral silicon-on-insulator bipolar junction transistor having a buried insulator layer; exposing the radiation dosimeter to ionizing radiation; determining a change in one of the collector current and current gain of the radiation dosimeter; and determining an amount of the radiation dose based on the change in one of the collector current and current gain.
1. A method for radiation monitoring, said method comprising:
providing a radiation dosimeter, said radiation dosimeter including a semiconductor substrate; a buried insulator layer disposed on said semiconductor substrate, said buried insulator layer comprising a plurality of charge traps; and a semiconductor layer disposed on said buried insulator layer, said semiconductor layer having an emitter, an intrinsic base, and a collector laterally arranged with respect to one another, and an extrinsic base in electrical contact with said intrinsic base;
exposing said radiation dosimeter to ionizing radiation;
determining a change in one of the collector current and the current gain of said radiation dosimeter; and
determining an amount of the radiation dose based on the change in one of the collector current and the current gain.
2. The method as claimed in claim 1 , further comprising the step of applying a positive back gate voltage to a substrate of said bipolar junction transistor.
3. The method as claimed in claim 1 , wherein the change in one of the collector current and the current gain is determined for a preselected value of a biasing voltage of a base/emitter junction of said bipolar junction transistor.
4. The method as claimed in claim 3 , wherein one of the collector current and the current gain is determined before and after the radiation dosimeter is exposed to ionizing radiation and the change in one of the collector current and the current gain is obtained by calculating the difference.
5. The method as claimed in claim 2 , wherein the back gate voltage is applied to a back contact, said back contact being electrically connected to a semiconductor substrate of the bipolar junction transistor.
6. The method as claimed in claim 1 , wherein one of the collector current and the current gain increases based on the amount of positive charge trapped in a buried insulator layer of the bipolar junction transistor.
7. The method as claimed in claim 1 , further comprising placing said radiation dosimeter inside a body to determine a dose of radiation received by the body.
8. The method as claimed in claim 7 , wherein said radiation dosimeter is placed proximate to a tumor in the body to determine a dose of radiation received by the tumor.
9. The method as claimed in claim 1 , further comprising placing said radiation dosimeter proximate to a body to determine a dose of radiation received by the body during medical imaging.
10. The method as claimed in claim 1 , further comprising placing at least one filter layer between the radiation dosimeter and a source of the radiation.
11. The method as claimed in claim 10 , wherein said at least one filter layer prevents some of the radiation from passing through the radiation dosimeter.
12. The method as claimed in claim 10 , wherein said at least one filter layer makes the radiation dosimeter more or less sensitive to some component of the radiation.
13. The method as claimed in claim 1 , further comprising incorporating the radiation dosimeter into one of an automobile, a building, an air filter, a portable electronic device, such as a computer, cell phone, music player, PDA or GPS, a passport, credit card, or driver license.