Abstract
For this dissertation, the radio frequency (RF) and millimeter wave circuits of transceivers were considered in order to analyze reliability issues with regard to the complementary-metal–oxide–semiconductor (CMOS) process. Three circuits were considered: a power amplifier (PA), voltage control oscillator (VCO), and mixer. In a stress experiment, the operation voltage was varied for the stress source, and the degradation of the circuit was monitored to analyze phenomena that degraded the device and circuit performance. The stress source conditions were controlled by the input power and voltage of instruments that were biased towards the gate and drain of the CMOS device on the circuits. In reliability experiments, acceptable values for the stress source were applied to the circuits to induce long-term stress. In the PA circuit topology, stage 1 was a driver stage, and stage 2 was a cascode structure. The circuit operation frequency was 5.2 GHz for a TSMC CMOS 0.18 µm 1P6M process. A cascode class-E PA was designed for fabrication because the amplifier was operated under high input power conditions. The input power, gain, gate–source voltages, and drain–source voltages had large values when switching during the transient state. Thus, the cascode transistor could suffer from the hot-electron effect and the degradation of the circuit performance. The experimental results were compared with those of a technology computer-aided design (TCAD) simulation to examine the reasons for the degradation of the circuit performance. The design and reliability of a CMOS current-reuse LC-loaded VCO based on the TSMC CMOS 0.18 µm 1P6M process were considered. The circuit comprised an n-channel MOS and p-channel MOS cross pair with a single current path oscillator structure, which allowed it to have low power consumption. The varactor component of the LC resonator was designed with a P-MOS device having low noise characteristics. The operation frequency was determined by the LC resonator, and a suitable VDD voltage led to low power consumption and low phase noise for the VCO. The negative-bias temperature instability (NBTI) affected the current for the reused VCO, which consisted of p-channel transistors. Previous studies had not examined the circuit topology experimentally, which provided motivation for this dissertation. Hot carrier issues for the degradation of the phase noise, transconductor, and threshold were considered. Finally, a millimeter wave mixer was considered for the TSMC CMOS 65 nm 1P6M process at conversion gains of larger than -5 dB. The coverage frequency was from 64 GHz to 75 GHz, and the maximum conversion gain was -0.96 dB. Two built-in Marchand baluns were used to convert the LO and RF port from single to differential. This can simplify the external passive parts and instruments used for the millimeter-wave band. The IF port provided excellent performance characteristic for the external passive parts and instruments. The IF port retained differential characteristics, which can be advantageous for circuit measurement during experiments. In this experiment, the mixer was operated at millimeter wave frequency range. Long-term and dynamic stresses on the n-channel metal–oxide–semiconductor field-effect transistor (MOSFET) device resulted in the hot carrier effect, which degraded the mixer performance. This increased the threshold voltage and gate leakage current and decreased the drain current. A stress measurement experiment was performed under different stress conditions for the n-channel MOSFET. The results showed how mechanisms such as a hot carrier and high electric field influenced the device characteristics under long-term stress.