| Over the past decade or so, the Power Integrated Circuit (PIC) market has emerged as an area with the potential for rapid growth. By combining one or more power devices with logic and control circuitry on the same die, PICs offer simplified design, reduced system costs, and increased reliability. However, the expansion of this market has been checked, in part, by the shortcomings of the traditional Junction-Isolation (JI) scheme used to isolate the power devices from the logic and control circuitry. Fortunately, recent advances in the fabrication of Silicon-on-Insulator (SOI) substrates promise to bring affordable dielectric-isolation for PICs in the near future.; To take full advantage of the synergy between PICs and SOI substrates, it is first necessary to investigate the physics and technology of power devices in SOI substrates. Specifically, the physics of lateral power devices, which are dominant in PIC applications, must be addressed. This research was undertaken to explore the changes in the physics of lateral power devices due to fabrication in SOI substrates. To achieve this goal, analytical models have been derived and correlated with device simulations and experimental results. The devices which were studied include the Lateral Double-diffused MOS (LDMOS) transistor, the Lateral Insulated-Gate Bipolar Transistor (LIGBT) and the Lateral MOS-Controlled Thyristor (LMCT). New device structures have also been explored in an effort to exploit the advantages or mitigate the deleterious effects of the SOI substrate.; The significant contributions of this research include an analysis of the breakdown voltage of lateral power devices in SOI substrates, models for the on-resistance of LDMOS devices as a function of SOI layer thickness and substrate potential, the demonstration of several new LIGBT structures which offer improved immunity to latch-up, an analysis of the turn-off transient of minority-carrier power devices in SOI substrates, and the demonstration of several SOI LMCT structures. These investigations have found that, compared to equivalent JI devices, SOI devices offer improved high-side switches, faster switching minority-carrier devices, and superior LMCT structures. |
