| Summary: | 碩士 === 國立雲林科技大學 === 光學電子工程研究所 === 95 === Heterojunction bipolar transistors (HBTs) have the advantage of low turn-on voltage, high cutoff frequency and high power density because of their superior material characteristics and structures. There are several material systems based on different substrate materials, and each shows a unique characteristic. For example, the well-known characteristic of negative difference resistance (NDR) in GaAs-based HBTs may not exist in InP-based HBTs. The different properties attribute to the different materials and layer structures of emitter, base and collector.
In this thesis, DC parameters and thermal parameters are extracted and applied to the VBIC model. A DC model without non-ideal effect is built first, and then non-ideal effects are considered later. Form the collect current (IC) versus collector-emitter voltage (VCE) characteristic, if we observe a positive slope in the low collect-emitter biasing region, it can be attributed to Early effect. If the IC rises remarkably in the high collect-emitter bias region, then we are assured that the device is influenced simultaneously by self-heating effect and avalanche breakdown. According to the different device characteristic in each non-ideal effect, we are able to establish a procedure to separate the non-ideal effect effectively and to describe the device performance in the VBIC model.
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