Abstract
In recent years, integrated circuits technology has been improved according to Moore’s Law, but the speed of this trend becomes slower. In addition to the process issue of transistors miniaturization, the yield of the 3C products decreases because of the heating problem generated during circuit operation. Therefore, a new technology is needed to overcome the difficulties. The silicon substrate is the most commonly used material for modern integrated circuits technology because the cost and high integration level. However, the heating problem in silicon IC is still a concern. In this thesis, we focus on the AlN substrate which has better thermal conductivity and the cost is even lower than the Si substrate. This thesis focuses on design and analysis of the Integrated Passive Device (IPD) in AlN substrate. The device performance is expected to be improved for microwave applications. First, we use transmission line structure to analyze and optimize the process. Second, we design three IPDs in AlN substrate. The first device is Wilkinson power divider. The measurement result is with an insertion loss of -5.8dB and an input return loss of -9.6dB at 24GHz. The second type of devices are half-wave antenna and quarter-wave antenna. The measurement result shows an input return loss of -13.067dB at 23.3GHz for half-wave antenna and a input return loss of -14.465dB at 23.2GHz for the quarter-wave antenna. The third device is a IPD transformer to be integrated with CMOS PA by flip-chip. The measurement result of sample 1 shows an input return loss of -14.5dB at 20.6GHz and a output return loss of -2.39dB at 24GHz. The measurement result of sample 2 is with an input return loss of -0.28dB at 24GHz and a output return loss of -15.5dB at 20.9GHz. However, the PA did not show the expected amplification characteristics due to the contact problem in flip-chip process. By using HFSS and Sonnet, we analyze the impact of process and geometry on electrical characteristics of IPD in the AlN substrate for microwave applications. In the future, we can design more IPDs in AlN substrate according to this analysis result and improve heating problem for different applications.