ural space environment (e.g., protons, neutrons, alpha particles, or other heavy ions) strike sensitive regions of a microelectronic circuit. Depending on several factors, the particle strike may cause no observable effect, a temporary disruption of circuit operation, or even permanent damage to the device or integrated circuit (IC). Single-event effects may be broadly characterized as either non-destructive or destructive SEE. Examples of non-destructive SEE include single-event upset in logic or memory circuits (SEU, or equivalently, soft errors) and single-event current transients (SET) in photodetectors. Destructive SEE include such phenomena as single-event latchup (SEL, which can be either destructive or non-destructive depending on circuit design), single-event burnout (SEB), and single-event gate rupture (SEGR). Any of these effects can cause unacceptable system performance in space applications, and possibly jeopardize mission success. In this short course segment, we will examine the basic physical mechanisms causing single- event effects in microelectronics for spaceborne applications. We start with a brief overview of the particle environment encountered in space in order to get to know the enemy. We will then discuss the mechanisms and characteristics of many of the non-destructive and destructive SEE mentioned above in detail, including techniques for mitigation. Next we review modeling and simulation methods that have proved useful for gaining physical insight and predicting SEE in microelectronics. We conclude with a look into technology trends that may affect future device susceptibility to SEE and areas of emerging concern. Reflecting their relative importance in the commercial marketplace, most of this short course segment will focus on silicon MOS devices and circuits, but where appropriate we will examine other technologies of interest. BRIEF OVERVIEW OF ENVIRONMENTS Previous NSREC Short Course segments have given excellent detailed descriptions of the space radiation environment [1,2]. Sever