| Silicon is the dominant semiconductor in the microelectronic industry partly because of the stability of its oxide. Fabrication of three-dimensional structures is of particular interest for many new microelectronic applications. Also, the possibility of silicon optical integration is of interest because of the recent observation of luminescence from pores formed by electrochemically etching silicon. Photoelectrochemical (PEC) etching can provide a method for etching these three-dimensional features in silicon at high rates with good spatial selectivity and resolution. In addition PEC etching provides a way of monitoring and controlling the etch process unlike other etchants that require constant observation.;The mechanism for silicon electrochemical etching involves hole transport in the semiconductor, surface reaction and product dissolution. Understanding the sequence of steps and the effects of process conditions is needed for successful development of a controlled etching process with spatial resolution and selectivity. To accomplish this goal, silicon electrochemical dissolution was studied in nonaqueous solutions. Measurement of reaction rates, examination of the role of fluoride, hydroxide competition, and analysis of process variables was performed. In this work, the possibilities of using a more benign complexing agent, the fluoroborate ion (BF... |
