Sensors including complementary lateral bipolar junction transistors

• Main Authors: Tak Hung Ning, Michael Gordon, Kenneth Parker Rodbell, Jeng-Bang Yau
• Format: Patent
• Language: English
• Published: 19.04.2017
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; MEASUREMENT OF NUCLEAR OR X-RADIATION; MEASURING; PHYSICS; SEMICONDUCTOR DEVICES; TESTING

A monolithic integrated radiation sensor or dosimeter (and manufacturing method) to detect environmental radiation (e.g ionizing radiation, neutrons) includes a sensing structure (e.g SOI insulating buried oxide layer, BOX 22) and first and second lateral bipolar junction transistors (BJT, LBJT) of opposite polarity (i.e NPN and PNP BJT devices). The first lateral BJT 30 (Q1) acts as the radiation sensor; its base 33 electrically coupled to the sensing structure 22 (e.g BOX 22 or upper oxide 132 fig 5) and produces an output signal as the stored charge changes within sensing structure. The second lateral BJT acts as an amplifier whilst the polarity is such that the ionizing effect is minimized. At least one of the lateral BJTs has an inverted (base) configuration (122 fig 2). The base of the second LBJT amplifier is electrically connected to an output of the first sensing lateral BJT (e.g base/collector). The doping concentration of the base of the second LBJT is higher (e.g by a factor of ten) than that of the base. The output of the first sensing BJT is configured to pass current directly into the base of the second lateral BJT, and the output (collector) of the second BJT corresponds to the output of the second amplifying BJT device. The integrated radiation sensor may include a neutron conversion layer within the buried oxide layer or an oxide layer on top of the LBJT sensor base.