CMOS radiation sensor design in 130nm CMOS technology : a thesis presented in partial fulfillment of the requirements for the degree of Master of Engineering in Electronics and Computer Engineering at School of Engineering and Advanced Technology, Massey University, Albany Campus

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Massey University
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This research work deals with a CMOS radiation sensor design, which covers a new open source floating-gate MOSFET (FGMOSFET) device model for analog circuit design, Floating Gate Radiation Field Effect Transistor (FGRADFET) design, FGRADFET sensor output circuit design and their layout implementation using the 130nm IBM CMOS process. At first, a new FGMOSFET device model to facilitate circuit design is presented. In this model, the floating gate is charged by the Fowler-Nordheim tunneling effect. The equations representing the new device model were explored and verified on MATLAB. Verilog-A script was employed to transfer the equations and build the complete device model. The new FGMOSFET circuit model was plugged-in as a pop-up menu component in a standard 130 nm CMOS technology design library so that it can be instanced directly on a schematic editor palette for analog circuit simulation and design in a similar fashion as the standard MOSFET devices. Furthermore, the thesis describes the radiation sensor of FGRADFET that has an extra silicon area (125μm×200μm) as an antenna to sense the radiation from the environment. There are 16 PMOS transistors (1μm×2μm each) beneath the edge of the antenna to charge the floating gate. A radiation sensor readout circuit is also designed for this sensor. This circuit includes differentiator, pre-amplify buffer, chopper amplifier, low-pass filter and single-ended output amplifier. This integrated dosimeter has a 3.205mW power consumption and 2.33mGy -23mGy measuring range (The single-ended output voltage changes from 226mV to 967mV), which could be used for tremendous radiation exposure applications such as radiation therapy.
The following Figures were removed for copyright reasons: 2.5 (=Fröhlich et al., 2013 Fig 2), 2.6 (=Vasović & Ristić, 2012 Fig 1), 4.2 & 4.3 (=Garcia-Moreno et al., 2013 Figs 2 & 8).
Instruments, Research Subject Categories::TECHNOLOGY::Electrical engineering, electronics and photonics::Electronic measurement and instrumentation, Ionising radiation, Dosimeters, Detectors