| Comparing with the traditional semiconductor devices, such as GaAs and GaN HEMTs, InAs/AlSb HEMTs considered as typical Antimony based compound semiconductor (ABCS) devices possess very high electron mobility and saturation velocity, making them advantageous in high-speed, low power dissipation, and low noise applications. Especially, InAs/AlSb HEMTs present a very great developing prospect to be a good candidate of LNA in deep space exploration. Therefore, InAs/AlSb HEMTs are studied on the characteristics, device modeling, circuit design, and fabrication in this dissertation, which fills in the gaps of this field in our country.In this dissertation, the operational principle of InAs/AlSb HEMTs is presented, and the characteristics are analyzed in detail. It is found that the InAs/AlSb HEMTs suffer from gate leakage current and are influenced by the impact ionization effect because of its narrow band gap channel and Ⅱ energy band staggered structure, which degrading the DC and RF performances of the devices. Based on these special characteristics, three kinds of improved small-signal equivalent circuit models are established. Also the improved models can suggest the influence of the leakage current and the impact ionization effect on RF performance of the device obviously, and the S-parameter, Y-parameter, stability factor K, the current gain and mason’s gain can be predicated by using the improved models. Additionally, the noise model of InAs/AlSb HEMTs is studied and an improved noise model is developed.According to the above modeling method, the model parameters for small signal noise equivalent circuit are extracted based on published data from literature for InAs/AlSb HEMTs, and a Ku-band LNA is designed. The LNA is realized by two steps of cascade to form with inductance feedback in source, in which the first step focuses on low noise realization, and the second step is to enhance the gain performance. The simulated results show that the LNA has a very good performance in 12-18 GHz frequency range, including a high gain above 15 dB with flatness below 1 dBc, a very low noise figure below 1.5 dB, and a good reflect coefficient S11 and S22 below-10 dB.Based on the fabrication process of the traditional Schottky InAs/AlSb HEMTs and discussion of the characteristics of the fabricated device, a method is proposed to improve the gate leakage current by using InAs/AlSb MOS HEMTs to replace the traditional Schottky InAs/AlSb HEMTs, in which an isolated gate with high-k/MOS capacitor is used to replace the Schottky gate. A HfO2/InAlAs MOS capacitor is fabricated to analyze the gate characteristics. Comparing with the conventional Schottky metal and semiconductor capacitor, the MOS capacitor shows obviously low leakage current in the magnitude order of 10-5 A-cm-2. In the other hand, the leakage current mechanism is analyzed for the HfO2/InAlAs MOS capacitor with 10 nm oxide layer thickness, and it is found that the Schottky emission and F-N tunneling dominate the leakage current in the low bias and the high voltage conditions respectively. InAs/AlSb MOS-HEMTs with HfO2/InAlAs MOS isolated gate is simulated by using ISE software. The simulated results show that the gate control ability of InAs/AlSb MOS-HEMT is degraded comparing with the conventional Schottky InAs/AlSb HEMTs, however, the DC and RF performances are not changed a lot, which will provide a theoretical evidence for the further fabrication and applications of InAs/AlSb MOS-HEMTs.
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