Chemically flexible precursors allow low-temperature silicon-nitride deposition process

Alain Kaloyeros and colleagues at the Center for Advanced Thin Film Technology at the University at Albany--State University of New York (Albany, NY) deposited silicon nitride (SiN) films by a cost-effective, low-temperature thermal-atmospheric-pressure-chemical-vapor-deposition—AP-CVD—method. The researchers used a novel group of precursors to deposit the SiN at temperatures below 450°C. At the Materials Research Society meeting (Boston, MA) last December, Kaloyeros said that current thermally based deposition technologies for silicon-based compounds often require prohibitively high processing temperatures—typically more than 700°C. And although plasma-based deposition techniques allow lower process temperatures—less than 450°C—the risk of damage and contamination is higher. And developing technologies in optoelectronics and flat-panel displays will require even lower temperatures.

The AP-CVD method is unique because it takes advantage of the low dissociation energy of the primary bonds in the source precursors. These precursors are chemically flexible, which means that silicon, silicon nitride, or silicon dioxide can be deposited depending on whether hydrogen, oxygen, or ammonia is used as the reactant. Kaloyeros says that the potentially low cost of ownership of an AP-CVD system is a key consideration and that the technology can be extended to low-pressure chemical-vapor-deposition cluster tools.